Stuffing Boxes

from the

Sailnet Tayana List

I'm trying to get some sales/technical/installation info on Drip-Free Packing, the blue Teflon/grease that was the subject of a thread on this list a month or so ago. I've contacted the company several times and the info was promised, but nothing has shown up. Does anyone know if the company is having problems or what might be going on?

Second, since this packing seems to stop circulation along the shaft, does this place the shaft in an anaerobic environment that could lead to wastage?

Thanks, Coleman S/V Traveler February 2000

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WEST MARINE sells this packing under their own label, you might contact them for info. I just repacked my stuffing box with it and so far it has worked great; no drips and the shaft is not heating up.

Jim S/V SMILES (T37 Hull 407) February 2000

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Subject: Shaft and stuffing box

After rebuilding my 4-108 and dropping it back in with only removing, not changing the old rusty coupling. I have been able to move back the shaft sufficiently to install the new coupling. I want to get the engine aligned so I can test all is working well under load. The problem is now to get the shaft and the coupling to slide back toward the motor. I tried diving the boat and working it over with a four-pound hammer and a block of wood but it did not budge.

Question: if I remove/replace the packing in the stuffing box will the shaft loosen up enough to be moved fairly easily? (not sure how old the packing is and should probably be replaced anyway). Has anyone tried the dripless packing I have been reading about, and how well does it work? How difficult is it to replace the packing in the water?

Phill T 37 #101 October 2001

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Phill,

Sorry for the misunderstanding. I think I wrote out a overly long description of repacking the stuffing box a few years ago, and at risk of excess redundancy, it's pretty straightforward. It is easy to replace the stuffing. But you are raising two different issues. One is how to get the coupling back to the engine, and the other is how to replace the stuffing. Although they are possibly related, as you indicate, I would not completely remove the stuffing until you get the shaft back to where it can be re-connected to the transmission.

Thus, you can "loosen" the stuffing box collar, but do it very carefully, making sure that your bilge pumps are working reliably. Applying equal pressure on both side of the flange (i.e. on port and starboard sides) with a small jack, you should be able to gradually push the flange towards the engine. This is the point at which you should now carefully re-align your engine mounts. (I assume that you replaced the old mounts with new ones when you re-installed the rebuilt engine.)

Prepare to spend a few hours doing this the first time. Best to get someone who has done it to help, to avoid the possible disconcerted reaction some people have when they suddenly see large quantities of water pouring into your beloved boat.

Make sure that you have adequate electric bilge pump capacity, and that the bilge pumps are all working. Test them repeatedly to give you confidence in their performance.

Based on the age of your boat, I suspect that the stuffing box is built in a manner similar to ours. There are two bolts coming forward from the fixed part of the stuffing box. There is a collar with two ears that slide on the two bolts. The collar has a tube that extends aft into the main part of the stuffing box. The shaft should be 1.25 inches in diameter. The opening in the stuffing box is approximately 1.75 inches in diameter. The tube on the collar is slightly less than 1.75 inches in diameter. Thus you have a space between the shaft the inside of the stuffing box that is about 0.5 inches, or 0.25 inches all around the shaft when centered. This might lead you to assume that the proper wax laden flax should be 0.25 inches so that is will form a snug collar around the shaft. However, you may find it advisable to have two sizes of flax on hand: a roll of 1/4 inch (0.25) and a roll of 3/16 inch. The small size may prove necessary to allow you to fit the material around the shaft and still push in the collar. The 1/4 inch material may make such a tight packing that you will have trouble getting it into place, and will have water pouring in as you find the sweat on your brow turning to a flood with your increasing anxiety. When you push the collar back into the stuffing box, it will compress the flax, and the 3/16 material will be just fine most of the time.

Read Nigel Calder or any other good maintenance manual on how to re-stuff a stuffing box. You will cut a series of pieces of flax so that it exactly completes a single ring around the shaft. Cut the ends on a bias so that it forms a good seal. The length of the flax pieces should not be too long or too short. Cut at least 4-6 pieces and make sure that they are the correct length for a snug fit around the shaft. Buy a good quality spiral tool for removing stuffing at any good chandlery.

Have several tools at hand, particularly a few 14-mm deep sockets to loosen and tighten the nuts on the stuffing box.

Make sure that you have lots of light down below.

Put several drops cloths under the prop shaft forward of the stuffing box. This will trap any tools or nuts that you may drop, and prevent them from sliding all the way down into the bilge. But keep the cloths loose enough to allow water to drain down into the bilge.

Test your bilge pumps again. The boat won't sink, but you will think things will get out of control as you are deep in the bilge and have fantasies of drowning in the lazarette as your boat sinks. Relax. Don't take a drink at this time. You will need all your faculties.

NOW:
Carefully lay out your various tools.

Loosen the nuts on the stuffing box. Place them in a very secure location. Do not drop them into the trough leading to the bilge. But if you do, remember, I suggested that you put some drop cloths in there to catch them.

Carefully slide the collar forward on the shaft. You may find there is an increasing drip of water. Relax, take a deep breath, and let it drip. If all the bilge pumps are working, you are in good control of the situation.

Before you remove any of the stuffing, check to see if the flax you previously cut in careful lengths really will fit. Put a piece around the shaft and push it into the stuffing box with the collar.

Take the spiral tool (looks like a miniature corkscrew) and carefully slide it into the stuffing box. Turn it to snare the piece of stuffing. Pull out the stuffing. You now know how to proceed. Now reach in and using the spiral tool, remove one of the older pieces of stuffing. The rate of flow of water will increase. Take comfort in the operation of your bilge pump. Probe for any additional material. Take a deep breath. No rush.

Now put flax into the stuffing box one ring at a time. After each insertion, tamp it in with the tube extending aft from the collar. Each ring should form a nice snug complete circle. Each circle should start at a different point on the shaft so that the ends are not all at the same point on the shaft to avoid leakage. When you have put in about 3 or 4 rings, make sure that you can still slide the collar on far enough to be able to secure it on the bolts.

Now tighten down the collar, and it should be about 3/4-inch gap between the collar and the fixed portion. If you have to add more rings of flax, do so. If you can't get even three rings in, then you didn't remove all the old flax.

Lean back and relax.

Check engine alignment. This is critical. Secure the coupling flange with the four bolts.

Start the engine and let it warm up. Leave it in neutral. Make sure you are securely tied to the dock.

Have a second person in the cockpit.

You should now go back into the lazarette. Have them put the tranny in gear. Be very careful that you don't have any clothing that could be caught in the rotating shaft before you do that.
Watch the shaft and stuffing box. There should be a slow dripping from the stuffing box. If there is none, the stuffing box may be too tight. Put the tranny in neutral.

Loosen the nuts on the stuffing box ever so slightly. Put the boat in gear and check for dripping. As the flax settles in, it will increase the rate of drip. Now carefully tighten the nuts. It should drip about 2-8 drops per minute.

Do not rush.

Now climb out of the bilge.

Now you have that beer.

regards, Harvey October 2001

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Just at the local boat show. The Shelter Island Boat Yard people had a large booth where they were displaying the PYI PSS dripless stuffing box. The exhibitor then suggested that rather than spending several hundred on the PSS and its installation, I should try out the GFO Gore-Tex and Teflon stuffing material. About $20 worth of material would be enough for the T-37. Very interesting material. I mentioned it to a friend with a big ocean fishing boat, and he said that he had been using it for 4 years, and it ended the Too-Loose/Too-Tight sequence of repeated adjustments immediately. He received a free sample directly from the manufacturer and ended years of fiddling with the stuffing box.

Anybody else had any experience with this material? As with many of the Gore products, they are based on very clever design and application of materials sciences to deal with the various aspects of a problem.

regards, Harvey January 2002

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Bob,

Just managed to find more info on the GFO at the webpage for E.F. Gore, Co.

http://www.gore.com/en_xx/products/sealants/packing/gore-tex_valve_stem_packing.html
I also include a quote from their page on packings.

"Packings"

W. L. Gore & Associates manufactures a full line of high-performance compression packings. These materials are chemically inert, highly abrasion resistant, and able to withstand temperatures up to 550°F (228°C). Our packings can be used in virtually any static or dynamic application requiring compression packing in your facility.

GFO® Packing - Unexpected packing failures are a thing of the past. Reduce downtime and cut maintenance costs with compression packing made from long-lasting non-asbestos GFO® fiber. Chemically inert, with few exceptions, over the entire 0-14 pH range. Withstands temperatures from -400°F to +550°F (-240°C to +288°C). For any type of pump - centrifugal, rotary, turbine, reciprocating. For valves, agitators, mixers, dryers, and refiners.

GFO® Marine Service Packing - Ideal for use in stern tubes and rudder posts. It runs virtually leak free and does not damage expensive propeller shafts. Helps keep bilges dry and lasts longer than flax. GFO® marine service packing cuts easily and is easy to install. When it is time for haul out, GFO® marine service packing is easy to remove from the stuffing box. Used by the U.S. Coast Guard, specified by the U.S. Navy, and approved by the American Bureau of Shipping. "

Harvey J. Karten January 2002

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I found a place in Ft. Lauderdale that sells the GFO. Emarine.

$17-$56 depending on shaft size, etc.

http://www.e-marine-inc.com/products/gfopacking/packing.html

John Reynolds January 2002

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Alan,

We had persistent problems with our stuffing box, with continuous leaking, etc. I was planning to put a PSS seal on our shaft, but the shop that installs them on Shelter Island suggested that I first try using the GFO Teflon braid from Gore-Tex. This is completely different product from the Teflon Stuffing material sold at West Marine and most other places. I've now had it in place for about 1.5 months, and it has finally controlled the leakage, while keeping the shaft cool. The cost of the GFO packing was a total of about $20. The mechanic could have sold me the more expensive PSS plus the installation charges, so this was a trivial cost for a successful (so far!) experiment. You can track down the Gore Company website and find their web page about their GFO packing.

You might try that route. The other advantage of GFO is that this can be repaired even at sea, if it did start leaking. The concern about the PSS expressed by several mechanics is that you have to haul the boat to install it, and if it blows out, you are in real trouble. The PSS/PYI people clearly state that the PSS has to be put in place with the boat on the hard. On the positive side of things, I have not personally heard of any reports of it blowing out. But I did wonder what is wrong with the PSS on Charles Freeman's T37?

regards, Harvey J. Karten February 2002

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Can you provide the dimension on the Gor-Tex packing that you used? I understand that 1/4 is recommended but I understand that others have found 3/16 more user friendly.

Sid Rubin February 2002

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Alan and Sid,

The dimension I used was the 3/16". I had to go to the slightly smaller size as our shaft is somewhat eccentrically placed within the stuffing box. The 1/4" couldn't fit fully around. That meant that I had to use an excess of 3/16" to compensate for the greater gap on one side, but it fit perfectly on the other side. The company says that you should be able to restuff using a single small pack of material. But since I had to use one size smaller, I needed two packs. So far - it works well.

Alan - as far as the vibration is concerned, check several things:

1) Condition of motor mounts. If they are more than 10 years old, they should probably be replaced.

2) Remove all the material from the stuffing box and replace it completely with the GFO Teflon/graphite braid stuffing.

3) Very carefully align the motor relative to the shaft and stuffing box. If you haven't done this before, I suggest that you hire a friendly and skilled mechanic who will show you how to do it properly.

4) After the initial alignment, install a PYI isolation coupler. This serves two purposes - it reduces the prospect of shaft damage in the even that your prop snares an object, and it helps reduce vibration.

5) Check your shaft to make sure that it is true, check the cutlass bearing for wobble

6) Check the prop for imbalance. Once you have the vibration under control, I would also check the accuracy of your Tachometer. We found that after replacing our alternator with a new unit, that our tachometer is reading 20% lower than the actual value.

7) At that point, depending upon the present material used, consider replacing the sound insulation material. Our engine box was "insulated" with cheap acoustic tiles made of some sort of wood particles. The wood fragments dropped into the bilge, and were a source of potential problems for the bilge pump. We replaced it with a modern sound insulation material with foam, weighted middle layer and aluminum reflective foil. I still don't like to motor, but at least it no longer jars my teeth nor deafens me. Engine efficiency has improved.

regards, Harvey February 2002

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I bought from: http://www.e-marine-inc.com/

Jim (SMILES) February 2002

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http://164.109.56.82/english/ipd/sealants/packing_GFO_Marine.cfm
Alan Jett Alliance Studios February 2002

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Hi Rich

Thanks for the information but my shaft does not have a nut on it at the flange end. There is a keyway that I managed to get out yesterday but the flange still eludes me. I am getting to the point that I will probably cut the shaft and have the flange pressed off. After 18 years it's unlikely it will come off any other way.

Andy Windy Blue April 2002

Andy
The shaft is secured to the coupling with a set screw and a key. The coupling is in two parts. One side is secured to the shaft and the second part is secured to the transmission. he two halves bolt together. I have a 4-108 and the flange has 4 bolts that hold the two halves together. These four bolts are the ones being described for removal. Slide the shaft aft with the coupling attached and place a 1/2-inch nut between the two halves of the flange. Using longer bolts, tighten the 2 halves of the flange together. The shaft will move, providing the set screw is removed. Repeat the process with a socket next (a little longer than the nut), then possibly the socket and a nut. The process is tried and it works. It will save a few hundred dollars for a shaft.

Joe Sprouse Sojourn Deltaville, VA April 2002

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We have now had the GFO Teflon packing in place for a few months. Continues to perform well. Shaft remains cool, and almost no moisture comes in through the stuffing box. (Of course the stanchions, chain plates, hawse pipes, and ports left open are another matter!).

After the first week or two as the stuffing was settling into place, I have only had to occasionally touch the adjustment nuts on the stuffing box by less than 1/8th of a turn. The bilge pump rarely goes on any longer. All that money wasted on bilge pumps! (Ha! That's challenging fate!) On a more serious note - assuming that the shaft is OK, I have decided against installing a PSS dripless seal. The problems associated with removing the flange from the shaft, and the recommendation that the PSS only be put on when the boat is on the hard, combined with the uncertainty about difficulties of emergency repairs in the event the bellows leaks when offshore, prompt me to decide in favor of the GFO. The PSS is not Fail-Safe, though it is highly reliable. But if it goes, there is big trouble. The worst that could happen with GFO is that I might have to add some more material. In addition, the price differential is substantial ($20 versus $400 - including parts and labor, but not the cost of hauling the boat). I can recommend GFO highly to those of you who are still considering installing a PSS to avoid the perpetual problem of a leaking stuffing box.

Harvey April 2002

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There was a thread on this bulletin board about a location in Florida that sells it for a reasonable price. About $20 buys enough to do the whole stuffing. I bought it at one of the small shops on Shelter Island. It is made by the Gore Company (of Gore-Tex fame).

I used the 3/16" wide material. Get a diver to pack some wax around the cutlass bearing. Make sure your bilge pump works well. Remove the stuffing box flange, and slide it up the shaft. Remove all the old stuffing. This might test the reliability of your bilge pump.

Put in several rings of the GFO. Push the flange back in, and tighten. If it goes too far in to the point that the flange is almost all the way in, remove the flange and add more stuffing.

Follow the directions about adjusting the stuffing box. After the initial settling in period when you may get a bit of leakage, you can eventually completely stop all leakage, but adjust it so that there is no overheating of the shaft.

That's all that there is to it.

regards, Harvey April 2002

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By the way, I am only referring to the GFO Teflon material from Gore-Tex people. There are other brands of Teflon stuffing material. I found that they were not very good, leaked after a short period of time, were very expensive, and finally had to be pulled out and completely replaced with ordinary flax stuffing.

The Teflon stuffing at West Marine and at Boat/US is not recommended - the GFO is a very intelligent combination of materials and design.

Harvey April 2002

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To buy:

http://www.e-marine-inc.com/products/gfopacking/packing.html
To Install:

ftp://ftp.sailnet.com/tayana/cutlass/GFOpack.pdf

I'm switching from the blue Teflon stuff to GFO

Ray Slaninka Red Bank, NJ April 2002

John:

I guess I'll go with 3/16. I think I could squeeze 1/4 but it might be too tight and I don't want to risk scoring the shaft. I think 3/16 is what most people use. And it is what the spec reads.

Ray Slaninka April 2002

I also noted that the manual says that you should use 3/16" stuffing, not 1/4". If the stuffing box were perfectly aligned to the shaft, 1/4" might be preferred.

The problem with sizing is exaggerated if there is any eccentricity in the centration of the shaft within the stuffing box. And there definitely is in our boat. Thus, the space available on the top of the shaft is slightly more than on the bottom. I can easily fit 1/4" above, but barely 3/16" below. I have had the engine realigned, and have checked the alignment on several occasions. The cutlass bearing is in good shape, and was carefully checked during our recent haul out. The conclusion was that the original installation of the stuffing box was not done with sufficient care and accuracy, so it is slightly eccentric.
I suspect that leaking stuffing box on our boat has been a problem since its original construction. That was also a reason I was considering shifting to PSS, as it provides greater freedom to align the shaft between only two points - the transmission coupling and the cutlass bearing. The stuffing box intrudes into this straight line if it is in any way not only eccentric, but if it is even slightly "off-angle" (i.e. - not perfectly parallel to the shaft, when the shaft is properly balanced between the transmission coupling and the cutlass bearing. Of course this assumes that the cutlass bearing is properly aligned!).

The great virtue of the PSS is that the shaft basically "floats" at that point, so the stuffing box does not have to be as accurately aligned. A great concern would also be that the stuffing box flange scrapes against the shaft, scoring it. The only saving grace might be that the flange is made of softer material than the stainless steel shaft, so that the flange will wear more that the shaft. But not a happy situation.

Packing the stuffing box with traditional flax with wax is a problem as the flax is relatively incompressible and hard, and takes more time to seat properly. It also doesn't conform well to the available space, and permits water to leak past it. The GFO material is apparently made of a fiber material that is far more adaptable, and includes both graphite and Teflon. The combination both lubes the surface of the shaft, and the Teflon apparently seals around it.

By using 3/16" material, you can more easily pack in and compress enough material to halt the leakage. While I felt that I should only use complete rings of material, I found that there was still a gap on the top of the shaft because of the eccentric stuffing box. I therefore added a bit of extra material on the top before putting in the last of the rings of stuffing. I compressed the collar to seat it all, removed the collar and then added a few more rings of GFO. Had I been able to use the 1/4", then a single package of GFO would have been sufficient. But since the 3/16" had to be used, I used two packs of 3/16" GFO. (Each pack is about 24" of material). Just to play is safe, I ended up buying 3 packages. I still have one unopened package, as a backup. The place in Florida sells them for about $9 a package. The place here in San Diego charges about $12 a package (for the 3/16").

regards, Harvey April 2002

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http://www.e-marine-inc.com/
order GFO packing on line. 2 day delivery in Richmond, Va.

Joe Sprouse April 2002

Subject: Rusting Propeller shaft

I have just replaced the propeller shaft and cutlass bearing because the shaft had started to rust in the area of the stuffing gland. The rusted area was about 5" long and extended from just out side the gland to the end of the stuffing material. I noticed last season that there was a leak from the gland and a build-up of a rusty colored paste around the gland. I decided that I would re-pack the gland with GFO after I read about it on this site.

Has anyone else experienced rusting of the shaft. Why should a SS shaft rust especially where it is exposed to air? It has been speculated that it could be electrically induced as followings. The shaft in my case was not bonded since both the flexible coupling to the gear box and the cutlass bearing are both insulating. I have also noticed that when it rains that water leaking into the stern of the boat eventually runs down over the stuffing gland. I have now bonded the shaft with a copper strap across the flexible coupling.

Greg Barnicoat KISH April 2002

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Greg,

Did the rusting begin only after you installed the GFO? Or did you install the GFO after the start of the rust?

regards, Harvey Karten April 2002

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Subject: Rusting Propeller shaft

I replaced my shaft three years ago when I got my boat..... It probably was a 304 0R 302 series stainless and had lots of 'rust bloom' all over the in the bilge exposed area near the stuffing box. Seeing the exterior corrosion, pitting, etc. I removed the shaft for inspection and found the area of the stuffing box packing was severely galled, pitted and corroded (in the section that is between the stuffing box and the cutlass).

At this time, I have the subject old shaft / worthless paperweight in front of me at the moment and report to you that I do have a 'rust bloom' on the area exposed in front of the stuffing box. Testing the rusted areas shows slight magnetic attraction whereas the rest of the shaft does not. Visually the 'rust' looks like a typical chlorine/halide attack on stainless - as would be similarly found vs. deaerated salt water; and, also exhibits surface cratering (chipping/stress corrosion) under the rusted area. It was the 'chipping' that led me to pull the shaft out and inspect it and to ultimately replace it. Fully exposed, I found massive catastrophic surface damage.

My *hunch* (based on long, long past engineering / chemistry experience in the foundry business, etc.) is that the salt water enters the packing area and with poor flow of lubricating water to keep up the needed oxygenation of the stainless surface, the fluid deoxygenates into the surrounding fiberglass, packing material, shaft log, etc. .... and begins fretting, etc. corrosion on the shaft. ...... and that why I prefer to use PTFE coated FLAX packing ... because it leaks a little and such 'sweep' volume of seawater through the packing keeps the shaft oxygenated to maintain the proper oxide coat on the stainless, etc. I currently work with various forms of Gore-Tex, etc. and am quite suspicious that the perfusion of oxygen through the PTFE packing onto the shaft is quite limited - typical gaseous intrusion pressures of such a wetted hydrophobic material are typically 25-75 psi, etc. (Sorry to again run against the crowd on this one).

Note: If I DID install pure Gore-Tex in future, I'd first soak the packing material in isopropyl alcohol to allow the material to wet-out so that the necessary (I believe) perfusion of gases would occur, .....of course it would then leak like regular packing and I would only benefit from the low frictional characteristics of the Gore-Tex but NOT the hydrophobicity.

Anyway it cost me over US$600 for a new shaft .... and it all started by seeing the rust zone on the shaft directly in front of the stuffing box.

BTW... I only use 3 rings of PTFE coated flax packing - 1 drip per 1-2 minutes not running (0,25 - 0,5 Liter/day), 5 drips per minute running..

If you'd like pics of the galling/corrosion I'd be glad to send.....

Rich Hampel April 2002

Hi Rich,

After reading the response from Sandra Blake I am even more convinced of the galvanic corrosion theory. In Dublin I had a swing mooring in the middle of Dun Laoughie Harbour and thus no stray currents. In Stockholm, I have a mooring in a marina with electrical outlets and hence the possibility of stray currents.

I also want to get some clarifications from your description below. In the stuffing gland, I had imagined that seepage of water in the stuffing gland was essentially a boundary effect, i.e. lack of perfect seal between the flax and shaft etc; and not the diffusion of water through the flax.

As for GFO if you believe their literature it has the following advantages over other packing material:

a. high thermal conductivity

b. low expansion

c. low friction, due to PTFE

d. soft/pliable material, hence easily molds into the gland cavity

All of which combine to give the gland a very low seepage rate.

I expect that the Gore-Tex fiber gives the material the high thermal conductivity, but I have not heard of this property before. Can you comment on this.

Greg Kish, Stockholm May 2002

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I just installed GFO packing. I used one package of 1/4" material and I got 4 rings out of it. Yesterday I launched the boat and 4 rings is barely enough as I almost ran out of adjustment before I stopped the flood. Luckily I got 2 packages and I will add more. Then I was reading an old TOG #26 and ran across a warning from a 1984 letter not to use graphite packing. I wonder what they meant back in 1984 by the term graphite packing? GFO has graphite in it. Also does anyone have a copy of the ABYC standards? If so, can you look up P6-6d and look for a warning about graphite corrosion. Derek, are you still reading these?

Back in January 2002, I posted this about graphite:

As far as the graphite in the packing, maybe I'm a little out there on this one, but I was concerned about it because of possible galvanic reactions. Graphite is a conductor. There is a pretty big spread between Silicone Bronze and Graphite in the Galvanic Series, although it is close enough to 316 stainless, it is pretty far from bronze. Graphite is the most noble metal, which means that you could start losing some of your stuffing box and even, to a lesser degree, your shaft. But even as I write this, I have to question how much metal would actually be lost and if it is worth worrying about.

Here's the rub, the 1984 letter warns about the shaft and the packing. Graphite and stainless are closer on the galvanic series than bronze and graphite. Go figure!

Ray Slaninka Tayana 37 May 2002

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We just put new GFO packing in last week also. One thing we discovered on our first roll of GFO was that, because that type of packing has considerable stretch to it, we cut the first batch of rings too short because we apparently pulled the packing a little too snug on the shaft when cutting it. (This was evidenced by the rings not completely joining end-to-end when installed.) We wrapped a little duct tape around the shaft when forming our second batch of rings, and they came out perfect. You might want to check this out before you add more rings.

Regarding your question about galvanic corrosion, I seem to recall reading somewhere, perhaps Calder's book, that ABYC does proscribe the use of graphite packing. I don't think GFO packing has anywhere near as much graphite as the true graphite tape packing that caused all the problems in the past, but I don't know for sure. This is definitely worth checking out. The Gore Company that makes the stuff has an 800 number. I'll see if I can dredge it up and will give them a call.

Dayton Eckerson T-37 #215 May 2002

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Dayton, Ray, and others

The concern about the graphite is probably something that Gore Company can answer. They claim that the U.S. Navy now uses GFO in their stuffing boxes. I would hope that this concern was addressed in the formulation of the MilSpecs on this material. I would hate to think that a Destroyer would suddenly lose its prop shaft while in the midst of a move to avoid a submarine!

Yet another month has gone by and the stuffing box continues to work well without excessive leakage and no heat buildup.

regards, Harvey May 2002

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Protection is provided by the proper zinc mounted on the shaft or prop.

Rich Hampel May 2002

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Saga # 3: The Dripless Seal

Kamaloha had a dripless seal which was rather tired and had no "spring" left to the bellows, and leaked fairly prodigiously while turning. With the boat on the hard it was time to replace it. An easy project, right?

1) Chop off and peen out the corroded split pin.

2) Borrow the world's largest spanners to spin off the prop nuts.

3) Curse and cajole and several hours later finally succeed in banging and gear-pulling the prop off.

4) Remove the batteries to get to the aberrant dripless seal.

5) Try the trick of pinching a sparkplug socket between the tranny and the propshaft to press the flange off the shaft. In your dreams! I now know what it takes to stretch four 3/8" threaded rods to the breaking point. Having done so, borrow the big spanner and gear puller again, then soak the flange in cutting oil, heat with blowtorch while cooling prop shaft. Bang, curse, repeat. Ah, a millimeter movement after only two hours! Repeat cycle. Seven hours later, prop flange finally comes off and shaft is free.

6) Clean up the shaft. Luckily it is corrosion-free and looks quite good. Carefully hone prop flange corrosion out to make a nice snug fit onto shaft.

7) Oops-- misalignment. For those that have never seen the dripless seal, it is fitted by removing the bronze inner flange to the old packing seal and flipping it about so the flanges are tight together, then hose clamping the rubber bellow of the new seal to the old inner flange. Well, careful inspection shows engine has sagged in its mounts over the years, and the hard prop shaft has cleanly worn the bronze flange to a mere paper-thickness on the bottom side. Scary!

8) Find an old bronze pipe-fitting in the junk bin at the machine shop and mill it to make a new cutlass bearing flange.

9) Align shaft.

10) Smooge and attach new seal. Oops... the larger diameter bronze fitting we just made doesn't allow enough space between the old cutlass bearing studs for the bellows to fit. Remove, clean out the smooge, and grind off studs to just long enough for nuts to fit.

11) Now there is just enough room to get the bellows on. Smooge with 4200 this time just to give it that extra little oomph to the seal.

12) Fit prop shaft, flange, and bolt it all together.

13) Hmmm, can't get the leverage required to press SS mating doughnut the required 1" into the bellows. Fiddle with various means of obtaining leverage for another hour.

14) Finally, refit the prop, nuts, zincs, and split pin.

Pretty soon my wife is going to outfit the lazarette with bedding and a stove, I spend so much time down there...

Charlie s/v Kamaloha January 2003

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Charles,

Jeez! You really win the prize for the nightmare story of the day.

The prospect of a dripless bellows rupturing in the ocean was said to be unlikely - by the manufacturer. But a few different boatwrights expressed great concern to me about this prospect. The man I was about to contract to install a PYI dripless seal urged that I first try the Gore-Tex dripless packing. That was a year ago. It cost about $20, rather than $400. Worked beautifully and for the first time since we bought our boat, it no longer produced a steady flow of seawater into the bilge. Works great, and easy to change. I keep my fingers crossed hoping that it is not scoring the propshaft. But the bilge is almost completely dry. (Almost, but not completely! Some comes from rain, some from water that enters when I pull the speedo transducer to clean off crud. )

regards, Harvey January 2003

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I understand the angst over the PSS Seal. However, when you take a close look at them they are essentially the same stuff as the rubber hose used for the raw-water intake, so I figured the likelihood of a rupture was about the same. The old one was on there for 10+ years as near as I can tell, and the rubber had not deteriorated, just lost the "spring" to the bellows so it was hard to put much tension on the seal. I did have sufficient angst over the thing popping off the bronze fitting that I used 4200 to make the connection this time; that stuff is awfully hard to take apart. Plus, the bellows compression puts a lot of pressure on the connection to keep it in place. I assuaged my angst that way. The scariest part was the worn bronze fitting. I suppose you can argue that this problem was hidden by the sealing properties of the PSS seal. Had it still been a regular stuffing box, the wear would still have happened, but it would have shown itself earlier due to the loss of seal and greater leak around the stuffing.

As far as the price goes, the new seal was about $100 on eBay; plus my day's worth of time, plus $25 to mill the bronze junk pipe fitting into a new flange.

I've got three bilge pumps; automatic, manual-electric, and manual arm-powered. I know from experience that the automatic can handle the full flow from a leaking prop seal. Last year the prop-saver sheared off and the whole shaft displaced aft, forcing the SS doughnut on the seal up the shaft and essentially opening up the seal. The bilge pump kicked in and took care of the water flow, a little too silently actually; I couldn't hear it running until I went below decks an hour later after running around trying to sail the boat into a marina slip after the drive failure. Maybe I'll wire the auto-bilge pump to the low-oil-pressure squealer (with diodes) so I really know when it is running.

If I were to try to go back to a regular packing seal at this point I would probably have to replace everything on the inside end of the boat, since I have no matching bronze fittings at this point. My bilge is not totally dry, either. I've got a very, very slow trickle from the rudder shaft packing seal that I didn't pick up on until after we splashed this time (it probably leaked 20ml in two days). Next time she is on the hard I'll tackle repacking that, probably with the Gore-Tex stuff.

Charlie s/v Kamaloha January 2003

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Hi Group,

I just replaced my metric (Tayana) prop shaft with a 1 1/4" shaft with a standard marine taper and standard threads for the nuts. It required that I also replace the coupler. The new coupler has a keyway for the shaft and uses two, 5/16" set screws set in dimples in the shaft to keep it from moving forward or back in the coupler. The keyway keeps it from spinning in the coupler.

Since I intend to order an Autoprop, I had to borrow a (power boat) three blade fixed prop until the Autoprop arrives. When I pulled away from the boatyard the drive train was making a horrible racket. It sounded like something was badly out of balance. I figured that it was the prop, because I had spun the shaft while I was in the yard and turned easily and alignment with the coupler was nearly perfect.

When I had cleared all of the bridges on the Miami River and reached Biscayne Bay, I decided to sail the rest of the way to the marina. After a beautiful sail of a couple of miles, I started the engine to hold me into the wind while I furled the sail. The engine revved all the way up but it was obvious that the prop was not engaging.

Imagine my surprise when I checked the shaft and saw that it had backed completely out of the coupler! The prop was up against the rudder. Fortunately, the Gore GFO packing I had put it was keeping any water from entering the boat. After identifying the problem, I thought it highly unlikely that I would be able to work the shaft back into the coupling by myself with no one to push it forward from outside the boat. I found however, that the packing, without leaking a drop, allowed me to slide the shaft forward to the coupler from inside the boat. Although the alignment was very close, it wasn't close enough to allow me to push the shaft up into the coupler. After scratching my head for a couple of minutes, it came to me that if I loosened the four bolts that connect the coupler to the shaft saver, I might be able to move it around the fraction needed to allow me to shove the shaft back into the coupler.

Unbelievable, it worked! It turned out that the problem was, when I installed the shaft, I had to align the set screws with the matching shaft dimples by feel as I couldn't see into the set screw holes. Apparently I missed the dimples and had tightened the set screws into the smooth part of the shaft where they quickly worked loose. As long as I was moving forward, in gear, the shaft was being pushed up into the coupler. As soon as I stopped the engine and began sailing, the shaft promptly slide back out of the coupler. Anyway, any of you that have ever tried to get a shaft to slide into a coupler on dry land know what a job it can be. It was a piece of incredible luck that I was able to do it while alone on the water.

I owe a large part of the credit to the Gore GFO packing which allowed me to slide the shaft forward, through the stuffing box and cutlass bearing, without allowing a single drop of water into the boat. I am absolutely sold on it. Good Stuff! BTW- no affiliation with Gore. I learned about it on this list, I think it was from you Harvey. I use 5/16"packing. It is tight but goes with just a little coaxing.

Regards, Gary Schieferdecker S/V Bold Venture January 2003

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TOGgers...
FYI, I just repacked Prudence's gland and she took about 7 rings of 1/4" Teflon.

John Kalpus Prudence Tayana 37 San Diego January 2003

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Since the keyway guarantees that the shaft is in the coupling in the right place rotationally, the only variable is the depth. When I reassembled mine I carefully lined up those dimples out of the boat where I could see them and marked the shaft with a scratch as to the proper depth. Then when I had to reassemble it in the boat I just lined up the scratch with the flange. Hopefully this did the trick; it's still in there for now at least. I also safety wired the set screws using my best aviation technique. After all the talk of Gore-Tex packing I can envision myself switching back to a stuffing box on the next haul; however as I mentioned I no longer have mating components of a stuffing box, and I predict that both halves would need to be replaced. Does anyone know if this is a "stock" item, a Grand-Deer never-find-one-again, or what?

Charlie January 2003

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Hi Steve,

I used GFO packing in my Cal 31 ( my last boat) for 2 years. After 2 adjustments it never leaked a drop. I can't wait to put it in my T-42 and dry up the bilge. Look on the net because you can find it considerably cheaper than the West Marine price. My link is corrupt so can't share it at the moment.

Jeff Orca T- 42 CC February 2003

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Nick,
Your note prompts me to add an update and status report on the GFO packing material in a standard stuffing box. After using GFO Teflon Packing for about 16 months, I can report that it really works wonderfully well. I have the original material still in place, the shaft remains cool when under power, and there is absolutely no significant leakage of water that I can detect. There might be a bit of seepage when under power, but the rare number of times that my bilge pump goes off could also be consequent to the gush of water that I get when I pull my speedometer transducer to clean it. I now monitor the bilge pump with a bilge pump counter. I installed it about a week ago, and the bilge pump has not triggered even once during this past week at the dock. There might be a bit more seepage when motoring, but clearly this is a huge improvement over the problems I was having 16 months ago, when I was using the standard flax (with or without Teflon - didn't seem to work very well).

The GFO works so well, that I find little reason any longer to consider installing a PSS dripless stuffing box. For a bilge counter, I found a surplus event counter with a small battery, and added a simple reed relay. When the bilge pump goes on it triggers the reed relay, which advances the bilge counter. The parts were throw-aways in surplus in our electronics shop, but should be easily obtained for only a few bucks at any electronics surplus store. Much cheaper than the $50 or $60 for a bilge counter at West Marine.

regards, Harvey T-37 La Jolla, CA June 2003

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We used some Greenish Blue putty, but paid even more for it. It was a total waste of money. We ended up going back to the regular waxed flax stuffing. But we could never properly control the leak, which was the reason we were considering installing a PSS dripless bellow. Fortunately for us, the man at the boatyard who we contacted about installing the PSS suggested that we first try GFO. It is a braided material with Teflon and carbon. He said that $20 for GFO would be a lot cheaper than $450 for installing a PSS! If it didn't work, he still would be glad to install the PSS. He also pointed out that if the GFO leaked, it would be no worse than with ordinary stuffing, and I could still go to the PSS. But as he also pointed out, even though PSS only rarely fails, when it does, it can be a disaster to deal with at sea.

I spoke with our diver about the idea of packing wax around the cutlass bearing, as he had once described that as a way to stop flooding when I was working on the flexible drive shaft coupling. He used a $2 wax package used as the gasket for seating toilet bowls in homes, purchased at Home Depot. It almost completely stopped water flow as I removed all the old packing. (Or at least, I HOPE I removed all the old packing). Get one of those corkscrew like devices.

Based on the shaft diameter of 1.25" and the internal diameter of the stuffing box of 1.75", that should suggest that we use 1/4" (0.25") GFO. But the shaft was seated somewhat eccentrically in the stuffing box, and I couldn't fit the 1/4" GFO around all parts of the shaft. I also noticed that the box of stuffing flax that was originally on the boat was 3/16". The eccentricity also probably contributed to leakage and inability to get a good seal. I then shifted to 3/16" GFO, and packed a bit of extra material on the side with the bigger gap. Snugged it down and packed in a bit more. Removed the wax seal from the cutlass bearing. Then loosened the nuts on the stuffing box slightly and started the engine. Made sure it was securely tied to the dock, and then put it in gear. Initially there was a very slight amount of seepage of a carbon Teflon mixture. I ran it for a while (?15 minutes?), snugged it down a tad. Ran the engine again. Shaft was ever so slightly warmer just at the stuffing box, but still quite cool.

All serious leakage has been solved since then. After the first week or two with minor adjustment, it has not shown any notable leak. I did let is seep ever so slowly, and the pump may come once every few days for just a few seconds. But that happens only when I shift to a port tack because of the location of the float switch in the bottom of the bilge being affected by the residual water. It stays on for a few seconds. In order to be alerted to the bilge pump going on, I bought a small piezo buzzer at Radio Shack for about $3, and wired it across the automatic bilge pump switch (a black panel switch with 3 positions - Auto, Manual and OFF) located near the electrical panel. It is not very loud, but there is no mistaking it when you hear it.

Our primary bilge pump is a Rule 1100 with a built-in automatic float switch. I chose that unit rather than a separate bilge pump with a separate float switch because I had trouble positioning the float switch in the narrowing and curved bottom of the bilge, in a location that would remain constant relative to the pump. The integrated pump and float switch is a lot easier to deal with.

Harvey June 2003

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Subject: Stuffing box and dripless packing, bilge counter

We also have used the GFO for the last 12 months with great success. I unfortunately failed to record the size of the GFO we used, but I seem to recall that we ordered the 1/4" but they sent us the 3/16" and it fit just fine. Good luck.

Dayton Eckerson T-37 #215 July 2003

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Visit the link below to learn about GFO packing. We used 1/4" 6 rings which is 2 packages:

http://www.e-marine-inc.com/products/gfopacking/packing.html
Joe Sprouse Sojourn July 2003

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We ordered our GFO packing directly from the manufacturer. Go to www.gore.com/sealants/. They had an 800 number on that site and took our credit card order over the phone. Good luck.

Dayton Eckerson T-37 #215 July 2003

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Just a quick update of my stern tube and cutlass bearing replacement project in case someone is contemplating doing it, too.

After breaking three of the four studs which secure the stern tube assembly to the deadwood and then removing all parts of the broken studs from the deadwood area I found that Tayana screwed the studs into deeply (two inches) embedded hex nuts located in the deadwood. All four hex nuts had short pieces of metal rod welded on each side of the nuts as anchors. They were the same deal I found when I replaced all my chain plate studs.

I removed each of nuts and filled the holes with thickened epoxy, a little at a time, until they were full. I am going to drill and tap the epoxy to accept bronze hex cap screws (1/2" x 3") in lieu of the studs. Hopefully, I'll be able to replace the cutlass bearings much easier in the future.

Again, I will post pictures on the ftp site when it is all completed.

Regards, John Keefe CT37 ODYSSEA Youngstown, New York August 2003

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Subject: How to info needed - Stuffing box flax replacement procedure...

On the Norsea it was fairly easy to reach the prop area from an inflatable, especially if I had my kids stand on the bow. I found that wrapping the shaft with strips of old tee shirt so that the shaft and stern tube were well covered and as sealed as possible really helped slow the flow of water into the boat.

John, et al...

If you can reach the prop shaft on the outside of the boat, try covering it with a wax gasket made for a home toilet install. They're dirt-cheap, only a couple of bucks, and are very malleable. You can force it into the area around the prop shaft and stop most of the water from entering while you install your new seals. Good luck....

John Kalpus Prudence Tayana 37 San Diego December 2003

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John,
Just to second the recommendation of John Kalpus. I had the diver pack a $2 toilet bowl wax seal (from Home Depot) around the shaft at the cutlass bearing. This almost completely stops the entry of water, and will allow you to be relaxed about changing the packing. Buy one of those things that look like a small corkscrew that will fit between the shaft and the walls of the stuffing box. Get a few extra packs of the GFO. We used the 3/16" rather than the 1/4", since the shaft was slightly asymmetrically aligned relative to the stuffing box.

You want to really pull out all the old stuffing.

Pre-cut a series of rings, with a slight bias cut to compensate for the fact that the outer edge of the stuffing material will have a larger radius than the inner edge.

Make sure the bilge pumps are working, even though the load on them won't be that serious if you use the wax sealant mentioned above.

Take off the nuts on the collar, and slide the collar forward.

Using the "corkscrew" remove all the packing material in the stuffing box.

Pack in the GFO rings. Start with two and then put on the collar and push the rings back into the stuffing box. Add a few more rings, until you can barely get the collar on far enough to put on the nuts to hold it in place.

Tighten it down moderately.

Remove the wax from the cutlass bearing.

Turn on the engine. Run it in gear while tied up securely to the dock. You will get a bit of leakage. You want it snug, but not so much so that the shaft gets too warm. As it settles in, you may get a bit more leakage.

Shut off the engine and tighten it a bit more. Do this a few times over the next few days. As it settles in, you will reach a point where the shaft is barely warmer than the environment, and you no longer get any leakage. (Well, maybe a drop every few minutes, or even less.) Once it is properly seated, you will only have to check it every few weeks or even every few months.

GFO is really terrific stuff, and vastly better than the junk sold at West Marine.

Harvey Karten December 2003

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Hi Jonathon,

Before you replace your present stuffing box setup with a PSS, if it is because of persistent leakage, I suggest that you first try using the Gore-Tex braided packing. A number of Tayana owners have used that, and found that it is vastly better than any other material, and has effectively stopped almost all leakage from around the packing. It is widely used on Coast Guard vessels these days, requires about $10-$15 worth of material. This is not the simple (but expensive) Teflon stuffing that you usually buy at West Marine.

The PSS is excellent, but expensive to put in, and does have a slight risk of rupturing with age. If it does that, you then have no way to easily control the flooding. If you are at sea, that can be a major
disaster.
We were planning to install the PSS due to persistent leakage, and the boatyard technician who was going to install the PSS, suggested that we first try the Gore-Tex material (even though he wasn't going to make anywhere near the money that he might have made by installing the PSS).

'Twas amazing stuff.

regards, Harvey April 2005

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Subject: Gore-Tex stuffing source

http://www.e-marine-inc.com/products/gfopacking/packing.html

Rich Hampel April 2005

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Jonathan,

I too see no reason to replace a conventional stuffing box in good condition with a PSS shaft seal. I've used 1/4" conventional or PTFE flax packing (replaced annually) for more than 20 years with no significant leaks. The T-37's rigid stuffing box works much like the one pictured in Fig. 9-25A in Nigel Calder's Boatowners Mechanical and Electrical Manual (2nd Ed), page 313. The only difference is that the T-37 uses a flanged compression ring in lieu of a packing nut and compression spacer. If your objective is to keep the bilge dry, why pay $225+ for a shaft seal that can fail catastrophically, when it costs less than $10/year to maintain a conventional stuffing box that gives plenty of warning (to anyone who looks) before it fails?

If your OEM stuffing box is deteriorated (due to corrosion) and it's time to replace it, then a shaft seal is worth considering. As an offshore sailor, however, I prefer the margin of safety that comes with a traditional stuffing box. If you've repacked and adjusted your boat's stuffing box correctly (Calder explains how to do this in his book) and it still leaks, it's time to pull the propeller shaft for inspection. When a stainless steel shaft has been in service 15 years or more, it's not uncommon to find significant pitting corrosion of the shaft inside the stuffing box (due to the lack of oxygen). When this occurs, the shaft's roughened surface will "chew" up the flax packing and the box will increasingly leak. Shaft wear inside the stuffing box (from the compressed flax packing) also leads to increased leaking, although not as much as with a seriously pitted shaft. In both cases, the solution is to replace the shaft (not the stuffing box).

Sue Canfield Aeolus T37 #-305 Annapolis, MD April 2005

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I second Sue's observation, especially about the shafting found in Tayana’s. My shaft was probably 302 (or worse) grade of stainless that was severely galled in the area that is encompassed by the packing, not so much crevice corrosion but simply a very aggressive chloride attack. After what I saw when I pulled my shaft, I would heartily suggest that if you never pulled the shaft for inspection - that you do so.

Incidentally, I had my new shaft polished, passivated and then electro-polished from the stuffing box on back.

Rich Hampel April 2005

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I'm going to be learning how to repack my original equipment stuffing box for the first this spring prior to launch. I want to use the Gore GFO packing material and looking through the archives it looks like 1/4" or 3/16" is the right size depending on the condition/shape of the stuffing box.

It appears to be sold in 2 foot lengths and by my rough calculation that would yield slightly more than 5 rings. Is one 2-foot piece enough? Thanks for the help in advance.

John s/v Tortuga 1979 T37 Ketch #175 April 2005

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Hi John,

If your flange and shaft are eccentric to each other, you will have trouble using the 1/4". In that circumstance, you will have to go to the 3/16", jamming in a bit extra material on one side than the other. But with the smaller size material, we found that we needed almost two full packages of 2 feet each. Still a hell of lot cheaper than a PSS.

regards,Harvey April 2005

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All you need is the 1/4". If because of alignment/tolerance/interference, etc. you need 3/16" just lightly "tamp" the 1/4" with a hammer etc.; but, don’t try to make 3/16" material out of 3/4" material.

Rich Hampel April 2005

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Year and years is the useful life. For packing a stuffing box, consider that GFO etc. is a permanent installation until it ultimately abrades away. The base polymer is tetraflouroethylene (Teflon) one of the most stable organic compounds ever synthesized. In fact there is gaining widespread environmental concern over the stability of these and related compounds (including Scotchguard) as they will essentially never go away and they are rapidly 'accumulating' in the environment.

Rich Hampel April 2005

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Hi John,

I found that I had to add material after about 2.5 years. This is probably due to the off-axis installation of the original stuffing box, relative to the engine shaft. Assuming a cutlass bearing in reasonable condition, and proper alignment of the engine relative to the shaft (should be within a few thousandths), a shaft diameter of 1-1/4" and an internal diameter of the stuffing box of 1-3/4", you should be able to get by with 1/4" stuffing. However, our stuffing box was sufficiently off axis that I couldn't manage to push, squeeze or pound the 1/4" stuffing material (GFO) around all part of the shaft. I finally had to go with the 3/16".

My original notes on this (January 11, 2002):

I bought the 3/16", rather than the 1/4", to match the present stuffing.

If it leaks, I may then try the 1/4". It comes in nominal lengths of 24". Then went back two more lengths. Paid $10 each for the next two pieces.

1/12/02 Saturday- Spent a few hours removing old stuffing and then installing the new GFO stuffing. Each length was ca. 4-3/4" to compensate for the greater outer curvature. Chris Boyd packed the outer
rim of the cutlass bearing with wax to minimize water getting in as I removed all the old stuffing. Make doubly certain that the bilge pump is working properly.

Two problems, as always –

1) Shaft is asymmetric relative to the stuffing box aperture. Narrower on the lower margin. Thus I can barely fit 3/16" stuffing below, while the space above the shaft is roomy enough to accommodate 1/4" or more. Removed about 5 rings of material using the corkscrew-like stuffing puller. Packed in 6 rings of GFO. Initially only had enough for four rings, but then went to get more material. Bought two packages to play safe. Added 3 more rings, but then couldn't insert the collar. Took one out. Total of 6 rings. As I tightened it, the collar was fully inserted. Need to remove collar and add at least one more ring of GFO.

2) Very difficult to reinsert the collar. Then went out to motor. About 1.5 hrs at 1,200 to 2,100 RPM. Only a very small amount of dripping of graphite mixed with water. Shaft is slightly warm, but never hot. Almost a complete success, but not quite. Have to add at least one more ring of GFO. But looks very promising. Might have been better if i had been able to use the 1/4" GFO. Also, the job would go much easier if I could have found my long 1/2" socket wrench. Hope this helps.

regards, Harvey April 2005

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Hi All:

I, too, will repacking my stuffing box next week. I have never done this before, and would like as much advice as I can get before attempting it. So, all of you that have done this one (or many times)
before, and can remember what you didn't know before you did it, please respond.

What specifically should I look for as I attempt this process in terms of wear, potential pitfalls, notes for future maintenance? What tools and extra's should I have handy? Specialized? Homemade? Odd? Can I do this with the boat in the water? If I have to have the boat hauled, how much time should I allow for the process (remember it's my first time)? Size/length of packing material? What am I not asking that I should or could be important?

All your help is much appreciated.

Michael Quirk s/v Vacilando T37, Hull 242 Minnetonka April 2005

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Hi Michael,

Brace yourself if this is the first time you are about to repack your stuffing box. Do it on a day when you have LOTS of time. There is no need to haul out your boat in order to change the stuffing in the
stuffing box. A very simple solution is to go to Home Depot and buy a wax ring used for the base of a toilet bowl. Assuming that the water is reasonably warm, dive the boat, and stuff the wax around the exit point of the shaft at the cutlass bearing. Don't push it in too far, the goal is to minimize the flooding of water when you remove the stuffing. Water pressure will help hold the wax in place. When you are done, remove the wax. This was is so soft that it should not cause a problem, and comes off in a single piece. The wax ring costs about $2.50 - easily the best bargain in boating for reducing stress.

MAKE SURE YOUR BILGE PUMPS ARE ALL WORKING CORRECTLY BEFORE YOU START. I even suggest that you test the ability of your bilge pumps to handle large quantities of water by turning on a hose into the bilge. At the very least, it will help clean out your bilge.

Get all the pieces together before you start:

Wrenches for the nuts on the stuffing box. Note - I used the plural! You are almost sure to drop a wrench at a critical moment, and you don't want to try to find it in the depths of the bilge as water is flowing into the boat. Make sure that the wrenches you choose can actually fit in the available space.

A block of wood and a rubber mallet to tap the flange. Not a good thing to do, but ... Do not hit the flange with a metal hammer when you are trying to get the flange back in place or compressing the stuffing.
The wax ring (see above).

Stuffing hook from your local marine supply store. Get one that is narrow enough and long enough to reach into the depths of the stuffing box.

A flashlight and a small mirror on a rod to try to peer into the stuffing box.

Suitable stuffing material, and enough to finish the job. Get two packs of the GFO. If you don't need it all this time, you will have some extra available for the next time you do it (in about 2-3 years or more).
A wooden stick to push stuffing into the box.

Pre-cut lengths of stuffing material.

Spare nuts to replace those you drop down the bilge while working.

Tape and a felt tip marker

Pre-cut pieces of stuffing to make a snug ring around the shaft.

Lots of good light. Lots of clear space around you with good access to the stuffing box. Lay your tools

out in a neat and orderly manner.

Make yourself comfortable. You will be leaning over in a very contorted position, and you don't want to find yourself worrying about drowning while uncomfortably squeezed in the lazarette. Make sure that the hatch to the lazarette is securely held in the open position. It would not be pleasant to have it suddenly slam closed over you from a passing speedboat's wake, with water surging up from the stuffing box, as the bilge pump plugs and your head is barely above water. Not a bad idea to have a friend sitting in the cockpit to hand you items that you forgot, and also to provide reassurance. If you have a bad back, I strongly suggest that you hire someone else to do this. You have to remain in a painful bent over position for at least 20 minutes.

The rest is easy:

1) Pack the wax around the outside of the cutlass bearing.

2) Remove the nuts holding the stuffing box flange.

3) Make a mark on the top surface of the flange so that you will know the original orientation. The flange may have been distorted over the years, and may only fit in a specific orientation.

4) Remove the flange and slide it up the shaft. Test to see how difficult it will be to get it back into place.

5) Tape the flange high on the shaft to keep it out of your way.

6) Use the stuffing hook to remove the old stuffing. This is actually one of the worst parts of the job, as it requires a unique body shape to be able to get your arms down where they have to be to do this properly.
7) Water will now be flowing in. DO NOT PANIC. Remind yourself that it will be better to let the boat sink, rather than drowning in a dark lazarette. (I hope that your boat and life insurance are paid up!)

8) Fit in the pre-cut pieces of stuffing. Push them in with a small wooden coffee stirrer.

9) After you have put 3 rings of stuffing in place, try to reinsert the flange. You may have to tap the forward face of the flange with the block of wood and mallet, in order to push in the flange and get it to compress the stuffing. If you still have lots of thread showing on the flange bolts, remove the flange and add more rings of stuffing.

10) Snug down the nuts on the flange bolts, but not too tight.

11) Make sure that your boat is well secured to the dock.

12) Remove the wax ring from the outside of the shaft/cutlass.

13) Make sure that you didn't leave anything around the shaft that will foul it when you put the transmission in gear.

14) Start the engine and let it warm up.

15) Cautiously put the engine in gear. Take it out of gear. Were there any unusual noises?

16) Now you will need to have someone you trust in the cockpit. Climb back down into the lazarette.

Position yourself safely. Do not wear clothes with material hanging off.

17) EXTREMELY carefully look at the stuffing box and flange.

18) Have your friend in the cockpit make sure the engine is at idle speed.

19) Put the boat in gear.

20) Is water leaking in?

21) If it is, have your friend put the boat in neutral.

22) Tighten the nuts symmetrically on the flange.

23) Go back to step "16)". Turn off the engine. You should be able to turn the prop shaft without trouble by grabbing the coupling with the transmission.

24) If there is no leakage, does the shaft get hot when rotating.

25) It may take a bit of fiddling, but the shaft should stay barely warm to the touch after it has been running. If it gets hot (and especially if it so hot that you can't hold your hand on it) loosen the flange a bit.
26) Stop.

27) Take the boat out for a short ride around the harbor to help seat the stuffing.

28) Check to see if it is leaking. If so, tighten the flange nuts a very small amount.

29) Nothing wrong with slight seepage of water. That helps flush salts off the shaft. Yes, it is nice to have a perfectly dry bilge. But that isn't always possible on older boats due to wear and tear.

30) Have a cool beer.

Welcome to the club. Hopefully you didn't drown, and your boat is still floating on its waterline.

regards, Harvey April 2005

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I just did mine for the first time. I had a hell of a time finding the right tool to do it. A good spiral pick as recommended by Nigel Calder wouldn't fit in the 1/4" space on my V-42 and West Marine, Boat US & Boater's World no longer sell the cheap picks. However, I found an excellent set of 3 picks at Home Depot that worked very well. They look kind of like dental picks but they are built much stronger and my regular dental picks wouldn't work. Once I got the right picks the job went pretty well. I was on the hard and for my first time I think that was a lot safer.

Harry & Melinda Schell Sea Schell April 2005

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Harvey,
Great job on how to repack a stuffing box. I love all the detail. You need to write a book, Harvey! The ones on sale now always say something simple like, "Remove old stuffing." As you pointed out, there are 25 steps to doing this including tools, lighting, and body positioning. That's why it takes 2 hours to do a 15-minute job on a boat!

Sea story about stuffing boxes: when I got my V-42 long ago, I had it "professionally" commissioned by a Tayana dealer. They hauled my new boat with the sling on the prop vice the keel. As the boat cleared the water, the sling came off the prop and caught on the prop nut with a jerk that bent the shaft like a pretzel. Luckily, the boat stayed put until they got it back in the water. After replacing the shaft, it was "professionally" repacked. I thought the stuffing was too tight. I had heard that it should drip a little when first launched and should only be adjusted to stop the drip after motoring for an hour. Then it should drip twice a minute underway but not at all when docked. I argued with the "professionals" but gave in to their expertise. My first day underway, I put my new boat aground in a marina and momentarily went to full power to get the boat moving. After a short while, I heard the loudest, most agonizing "squeal" from my engine room. After the smoke cleared, you could see a cherry red stuffing box in the dark engine room. The stuffing box overheating and subsequent friction had taken my new Perkins from a full power condition and shut it down completely!

I finally went to a Lasdrop shaft seal 15 years ago. When it was only 5 years old, the plastic collar around the shaft was found cracked during an annual inspection and required replacement. The problem was that the screw that held the collar together may have been too tight. After 10 more years, I replaced the whole thing with a new Lasdrop since the rubber bellows was getting weak and the sealing face sometimes leaked when underway. The new models don't use screws anymore but hose clamps instead. On a couple of occasions while still in the water, I have had to slide the shaft back over a foot to change the transmission. There is a little bit of leakage while moving the shaft but then the bellows can be tensioned and there is no leakage while the shaft remains backed out. Otherwise, the Lasdrop seems to be a satisfactory seal and I never worry about a hot stuffing box.

Wayne V-42 C/C RESTLESS April 2005

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I prefer to pack repack the shaft on the hard, and also like to pull the shaft out for visual inspection. Remove the coupling, depending on clearance when the rudder is full to one side - drop the prop, slide the shaft out to where you can inspect where its riding in the stuffing box. If heavily scored or galled, take to a machine shop and 'dress' and polish the journal surface. Tayana’s don’t seem to have very good quality metal on their propshafts - about $600 for a new shaft.

Haven't checked the shaft on Sojourn yet but it's on the list for next time in the yard. I have had good luck in the past with repairing a galled and pitted shaft with a machine shop process of metal spraying. They turn down the damaged area just a little bit to remove the damage and get a smooth surface, then it's sprayed with stainless steel until it's built up larger then the shaft and then machined down to the required size. I had this done to the transmission shaft on a tractor where the reverse gear had ceased on the bearing surface, it still looked like new 8 or 9 years of hard use when I had to replace a seal in the trans... I was also thinking of having the packing area on the shaft polished next time it's out... Just had the same thing done to save a 400.00 dollar pump motor on a spa, I took it apart and the cost to repair it was 60 bucks with new bearings...

Ventura Bill April 2005

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Everything Harvey wrote sounded reasonable, but it is really not necessary to use the wax ring. The flow of water will not be more than your bilge pump can handle.

BTW, I once had a PSS shaft seal on the prop shaft and I removed it and went back to the Gore-Tex packing while the boat was in the water. In this case I did use a wax ring to seal the shaft and the vent holes in the stern tube from the outside and it worked perfectly.

A couple of extra suggestions:

1. Cut the lengths of packing (before removing the old) by wrapping the packing around the exposed prop shaft and slicing it with a razor blade. This way you will get exact lengths. If you use the little
corkscrew-like tool, remember to get one that is small enough to fit between the shaft and the stuffing box.

2. I've found that a hemostat or needle holder is helpful in pulling the old packing out. Cheap needle holders can be purchased in fishing supply stores.

3. Rather than a stick to push (tamp) the new packing into place, I use a 6" piece of 1" or 1.25" diameter thin wall PVC pipe cut in half length-wise. It fits around the shaft easily and insures that the new packing slides evenly into place around the shaft in the stuffing box.

Jim Smiley (SMILES) April 2005

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We bought a set of picks at Home Depot, too, and they ended up being junk. The picks came out of the handles on two of them. I ended up returning them and going to the local NAPA store and getting their heavier-duty set for about $7, IIRC.

Mark Kaynor "Rachel" April 2005

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Harry, Harry, Melinda, Bill, Jim, Mark, Bruce and others:

With all your help, advice and counsel, I replaced the packing in my stuffing box and all went exactly according to your descriptions. And, I will never again worry about performing this maintenance chore.
To be on the safe side, I bought 3 widths of packing material, and ended up using 1/4". There was enough room to put 7 rings in, so I did, but I suspect that 3 or 4 would have done the trick. The 7 rings used most of 2 packages of stuffing. The toilet base wax ring worked well, but a fair amount of water entered anyway; I wonder how much more would have flowed in w/o the ring??

The whole process took about 45 minutes, not including the dive time. 35 minutes to remove the old packing (I'll be more aggressive next time) and 10 to install the new stuffing and tighten down the flange. Bilge pump cycled about every 2 minutes for 30 seconds after the last old stuffing ring was removed.

After I got done, I wondered if there is a similar stuffing box for the rudder post? Does anyone know how the rudderpost is sealed from the water and is there a maintenance procedure for it?

Thanks again for all the help.

Michael Quirk s/v Vacilando T37, Hull 242 April 2005

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Subject: Rudder Stuffing Box

Is this connection like adjusting the nuts for the packing gland? Yes?

Is there a packing gland of some sort in the rudderpost connection on the inside of the hull? Yes, identical to a regular stuffing box.

Anyone with experience with this? I tighten mine periodically when needed. If you want to know if doing this affects your steering, you can try using a fish scale on the spokes of your wheel. After the wheel is turning, just read the pounds of force required to keep the wheel in motion. Make sure to attach it as far out on the spokes as possible and do it before and after the job. I just overhauled my steering pedestal, had previously replaced the pull-pull cables with Morse cables, and have gone over the entire steering system. It takes 3 1/2 pounds at 29 inches from the center to keep my wheel moving.

I can answer this question for the V-42. Unlike the hose setup on the T-37, it has a fiberglass "pyramid" or "cone (a foot tall) with a standard stuffing box flange on top. The bronze stuffing box flanges are clear of the water at rest but are underwater when moving. Checking for leaks can only be done underway. The same stuffing used for the shaft can be used for the rudder. The rudder shaft is a larger diameter than the prop shaft.

Wayne V-42 C/C RESTLESS April 2005

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Harvey's description of how to replace the packing was just fabulous. I had all the right tools, parts and pieces and since I had the water heater out I even had a place to sit.

First off I couldn't imagine doing it in the water with water flowing by, I'd be an absolute nervous wreck. My biggest challenge and lesson learned was trying to remove the old waxy stuffing material after the boat has sat through a cold Minnesota winter made for some tough pickin. A couple of the rings came out pretty much intact but several were just a waxy/hairy blob. A chunk got stuck on the
underside of the shaft and wouldn't budge. I eventually resorted to my trusty heat gun and gently warmed the contents, which really made a difference.

I'm still not 100% sure I got all the old stuff out, probably one of the advantages to the in water replacement method, I'm guessing you know for sure when that last piece comes out. Anyway I got 6 or 7 rings of new GFO in place with a steady drip and a 1/4" to 3/16" to go to reach the point where the retainer ring was previously. This weekend I'm planning on doing the break in process and hopefully
declaring success.

I want to say a special thanks to Harvey and everyone else who contributed suggestion and advise.

J. Ware s/v Tortuga 1979 #175 T37 May 2005

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