Water Tanks
  from the 
                Tayana List 

   I have a V-42 aft cockpit, hull 166.  Water tanks are leaking very, very slightly, less than 1/2 gal per day total.  Leaks appear to be on seams that are rusting slightly.  Viewing inside through access panels shows rusting on seams with other sections of tank in great shape.
 
   Has anyone had the same problem and what was solution?  Remove and replace or repair.  Any insight would be very helpful. Thanks.
 
Van Anderson									October 2000
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Scrub the water tank and clean and dry.  If possible wipe down the seams with acetone, mix a quanity of marineTex and apply to all seams.  Seal all water tank outlets and install a schrader valve in the vent connection.  While the marineTex is still wet, reinstall the cleanout plate and pressurize the tank to 3-4lbs and leave set for about 8 hrs. Then vent tank and restore all fittings.  This should force the marineTex into the holes in the seams.  

Tom Cagney									October 2000
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Van,
    Rockie and I talked with Jesse Frederick and Jim Kavle of Imagine Yachts in Annapolis and they suggest getting a company that will build a bladder tank to fit your tank and then cut a larger hole in top. Clean out the tank and install the bladder and fittings, manufacturing a larger access plate for the top. However if Tom Cagney is right, his approach sounds almost too good to be true, and should certainly tried first. Tom, have you been there before?

 Bill Truxall									October 2000
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Bill,
   I had leaks in the water tank on my 37 and used this method to repair the seams.  One thing I did not mention to Van, I used plastic corner edging that is sold in wallpaper stores to hold the marinetex and pressed it into the corners. It has held for several years and is worth a try. 

Tom Cagney									October 2000
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    One thing to keep in mind....Stainless Steel is a strange animal.  It has the most galvanically reactive metals all mixed into one alloy, yet it doesn't rust (too much)... One problem though, is maintaining the balance of metals during the welding process.  If you look around at all sorts of welded stainless, you'll see more corrosion in the welds because the welded area metallurgy was not well controlled and the weld is actually something other than stainless.... I noticed this happening on a welded stainless water lift on my previous boat... The welds failed, displaying pinhole leaks... Stainless tends to corrode more in a moist, oxygen-starved environment.... hence happening in the tank welds, which are submerged in water.... this is one reason I won't put those pretty, tight anti chafe covers on my shrouds, and why chainplates and lifelines fail....moist, oxygen starved stainless..

Matt Helms									October 2000
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I talked to a guy in San Diego today that repairs tanks, fuel mostly but water as well.  He is aware of two tank coatings, Ceram-Kote and Plastisol (sp).  They are both 2-part coatings with great flexibility.  I will know more next week and will send update then but for now  . . 

1) Ceram-Kote requires a #80 anchor surface.  This would require sandblasting to get to every nook and cranny.  Any surfaces missed in preparation would be a problem.

2) Plastisol (sp) can be applied to clean dry surface.  No sanding or other difficult prep necessary.

I also asked him about Tom Cagney's Marine-tex under pressure method and he agreed that would also work.  

Will meet him next week and update when I know more.  Thanks for the comments and help.

Van Anderson									October 2000
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    There is also an outfit in Rome, NY, called Microseal which produces a sealer material which is used to seal porous castings. In experiments which I did, I found that it would seal tanks with holes as large as 1/16 inch though it is most effective for sealing smaller leaks. Sorry, I don't have their number here but one can get the number from information.

Earl Potter									October 2000
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   There are very common strains of molds & mildews (especially aspergillis) that are extremely toxic and pathogenic.  (Harvey can probably fill in the neuro-toxicity potential). There are many documented/reported cases (especially in cities) by public health agencies, etc. of extreme toxicity gained by simply 'touching' them or especially inspiring their spores.  These are the black slime molds/mildews that grow on wet basement walls ..... and in the 'dark' spaces on boats.  Not all are toxic, most may be so - at least to some minor degree, etc. 

    Anyway.....I KNOW they grow prolifically in boats !!!!    I don't want to drink them, I dont want to wash my dishes with them, I dont want to rinse my toothbrush with them, etc.    The problem occurs when you draw-down your water supply from the tank.  These species grow best in the warm & dark locations (like exactly where your tank vent is always hidden). .....  and the tank vent is OPEN to atmosphere. 

    Scenario: You have a minor to occasional 'mildew' problem on your boat (everyone has one). You have no idea where the tank 'vent' is; or, never knew you had one. .. it's hidden under or behind some panel, .... is most probably in the dark (and with high humidty). --- mold/mildew grows all over the hidden space. You draw-down some water, air in-rushes to the tank, ... the mold/mildew spores are now in your tank. Aspergillis, etc. is now growing throughout your entire water system (it’s a matter of degree - but it IS there). 

    Without a 'bacteriological aerosol blocking filter', etc., the spores from these and other organisms are easily drawn into the vent and hence into the tank (the entry point is probably in your boat's mildew incubator!!!!)  Once in the vent tube, they begin to actively grow down the walls of the humid, dark tubing and eventually begin to grow on the humid dark walls of the tanks themselves (using the metal and plastic etc. components as their nutrient source). A cursory visual inspection will show (I never saw a boat's tank vent without this infection) what looks like 'algae' growing on the inside of tubing.  .... and, if you find it there in the vent, most certainly it has also infected the entire piping and tankage system.  Sometimes in grossly infected systems you can see the "algae" (discoloration) growing on the insides of the clear tubing that connect the various components - yum! 

    The easy prevention remedy is to place a 'bacteriological aerosol retentive' filter in the line (after you 'sanitize' the whole system) to prevent aspiration of the spores into the system during draw-down. Encapsulated teflonic (bio-retention rated) membranes (about 50-70 mm diameter, encased in a plastic capsule ---  ie.: Whatman #2101 @ $5.00 ea., etc.) are the current retention membrane of choice.  The 'economical' alternative is to simply take a large to moderate sized 'wad' of dry sterile gauze /sterile cotton .... and liberally "bandage" the open end of the tube with it. Keep it dry and change every 6 months or so.  Once you protect the 'vent' you wont have these 'critters' growing down into the tank.  Once an infection begins, it accelerates and promotes the growth of other organisms until you have a fermenting 'brew' going on in the tankage.  As each of these 'critters' sucessively infect and eventually die, they become the nutrient source for others, etc. etc. until all you are left with is a stagnant gooey mess instead of potable water. My claim (for the USA which has 'mostly' safe drinking water) is that THE PRIMARY source of tankage infection is the ***vent***  - totally abandoned, in a dark warm place, .... totally unprotected and totally OPEN to the atmosphere.   Would you drink out of a water cooler that had a tube that was open to the atmosphere... for weeks, for months, years even... and NEVER cleaned!!!!???  No you wouldn't, ....not twice.  

....... now consider then airborne bacteria, viruses, etc. etc. etc. etc. .....    

    The technical basis of all the above is a fairly simplistic methodology to lessen the infection potential of a "draw-down" (open to atmosphere) water tankage system; and, is based on the similar standard practice as is REQUIRED in a pharmaceutical, biological, food, or beverage plant's water system. 

    BTW - I know of several folks who consistently and repeatedly developed "respiratory problems"/asthma-like symptoms after several days on their boats... my recommendation was a thorough "killing of the" mold (includes tankage sanitization) and a "safe" removal process ( + tank vent ) .... 

    Result:  no more 'respiratory problems'.  

.... and just when you thought everything was fine and dandy, some smart-ass tells you your boat's water is probably poisoned ......  it just never ends.   :-(

regards, Rich Hampel							         November 2000
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    Without going into a long winded dissertation of sanitization of onboard potable water systems, once you have a contamination, the only surefire method is to disassemble, mechanically clean & scrub, then shock sanitize the system to prevent reinfection. Any discolored hose should be replaced as discoloration means that fungal, etc. species have penetrated into the plastic!  Commercial, industrial, municipal, etc. shock sanitization is by adding enough Clorox (there are other methods) to get up to 10 parts per million of free chlorine, let the chlorine digest (a few days) to stun/kill the growth, scrub, and reshock with Chlorine, drain, rinse, drain, rinse, drain, rinse, etc.  (You can’t do this if your tank is aluminum - as chlorine will react with the aluminum). If you dont remove the "dead bodies" by mechanical scrubbing, etc, those 'dead bodies' become a nutrient source for subsequent infections. 

    The 'maintenance' dosage of Chlorine is 1 parts per million (sufficient enough so that you can "just barely perceive a faint chlorine smell" with your nose).  

    The most probable entry point for most infection is the tank VENT which draws in spores, etc. every time you turn of the faucet and draw down the tank.  My usual (strong) recommendation after tank cleaning and sanitization is to place a hydrophobic bacterial retentive filter on the vent exit, or more cheaply - taping a large "wad" of dry sterile bandage gauze over the vent and keep it dry, change yearly.  Typical infections are usually molds and mildews including Aspergillis, etc. of which some species can be toxic (Its that black stuff that grows in the dark spaces of your boat.)  If you get continual reinfections..... change out and replace the entire vent line, etc. and add the gauze or blocking filter. 

    Keeping a 1 part per million 'maintenance' level of Chlorine (dont calculate the numbers, use your nose) requires that you dont use a carbon packed filter in the system as the carbon will remove the Chlorine from the WHOLE system. (Incidentally, the carbon pack filter will become a breeding/nutrient site for other microorganisms - I'd never ever have one on my boat) Shock sanitize with 4 oz. of Chlorox per 10 gal. Maintain with 0.4 oz. of Chlorox per 10 gal.  ... + add more to be able to notice the 'very faint smell'. (Commercially available Chlorox is a 5% solution.) 

hope this helps, Rich Hampel  						        July 2001
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    Yes, just take a large fist-sized 'wad', cover the end of tube and tape it in place, leaving the maximum of exposed area possible.  Better, ... you can take absorbing cotton (loose) and make a 'sandwich' with the gauze as a covering to hold the cotton in place.  The gauzed end should be located high enough so that it cannot become wetted by water from the tank.

Rich Hampel  									        July 2001
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 -  Where would i be able to purchase such a filter?

Whatman-Nuclepore Corp. (part No. #2103), PTI Advanced Filtration, Inc., Pall Corp (Part No. DFA4001FRP),  Millipore Corp. .... but they would hit you with a hefty minimum charge over the $50.00 to $75.00 unit cost. 
Any validated bacterial retentive filter (HIMA) made with a hyrdophobic PTFE 0,2µM pore size. 
If you know someone in the pharmaceutical, fermentaion or biotech industry, they would be a good source for you as usually these filter manufacturing companies will not sell such a filter for 'commercial/residential' purposes. 
  
-  Is this carbon pack filter the same filter u are talking about in #1?

No the 'carbon filter' is what folks usually apply just before an outlet spiggot to improve 'taste' - typically 10 inches long X 2-3/4" dia and fit into a plastic housing.  (I think they are outright dangerous on a stagnant system such as a boat).

Rich Hampel  									        July 2001
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Bill,
    When we first thought about tank replacement, we considered using the SS bilge water tank as a diesel fuel tank....but ended up deciding against it.

    Though our SS water tank never leaked, it did have some surface corrosion going on and I think it was only a matter of time.  The most prominent was towards the aft bottom - deep bilge area.  From what I recall when I looked in the tank, it didn't look real bad, though there was some rust showing along the welds. And since our boat is a little over 20 yrs old (#170), I leaned away from using it as a fuel tank.  What convinced me even more was what I was finding when reading about using SS for diesel fuel; N Calders book, among others, touches on this topic.  He says that though "SS is considered by many to be the ultimate fuel tank material, in fact it can be some kind of fore-aft risers (at least 1/2" tall or so) to get the tank off of the bilge sole.  When I took my tank out, there was a bunch of collected dirt/crud/mud etc under the tank.  With the risers / added air under tank - it would add better airflow and you can periodically hose out the bilge and keep it clean under the tank....at least this is what I plan to do, and is what I've done on boats past; usually clean/hose out bilge at least few times a year to keep it clean and work the pumps etc.

    Dashew, in his 'Offshore Cruising Encyclopedia' book, touches on this topic briefly.  He points out that "the sulfer in diesel fuel can combine with moisture in your tanks to create real corrosion problems."......"SS has to be used in heavy gauges for it to last a reasonable length of time."

    There was also a real good article in Cruising World on tanks in October 2000.  If using SS - they also talk of using 316L or 317L (L=low carbon), in 12 gauge )0.105") or thicker.....SS fuel tanks "may suffer from corrsion, specifically crevice corrosion.  That happens when SS is robbed of its supply of oxygen and kept wet, such as in stagnant bilgewater."  The article goes on to talk about 'weld decay' or 'carbide precipitation "along each side of the weld if low carbon SS is used, the heat from the welding process drives the chrome ions out of the weld, leaving strips of mild steel along either side of the weld, which will begin to rust."  It's been a while since I looked at the inside of our SS tank -- I don't remember if ours was rusted on each side of the weld or just rusted on the weld seems in general.

    The aricle goes on to say that....."the welded seams along 90-degree corners tend to be brittle.  Over time they can work-harden, experience fatigue corrosion, and rack."......"SS tanks may be used for fuel, and to be ABYC compliant, they should be cylindrical and not exceed 20 gallons.  That's because big rectangular tanks flex more and their welds are subject to more fatigue.  Obviously, few SS fuel tanks are ABYC compliant"

   Well, I hope there is something in this lengthy email that is helpful to you.   I think I have a couple other sources about tanks etc, but these were what I dug up for now.  As I mentioned, we seriously considered using the SS tank for fuel also.  If it didn't have as much surface corrosion (though it wasn't visibly extremely bad) we probably would have used it.  Maybe yours is in better shape than ours was.  I think I recall there being an article or two on this topic in the TogNews letter -- conversion of SS tank to fuel etc.

    We are going to be doing extended offshore cruising...hopefully for years, so (as you know) we ended up opting for new Vinylester fiberglass fuel tanks.  We didn't want to have any question as to the condition of such a vital piece of the boat.  Maybe Rich H will throw in his 2 cents, he seems like he would be knowledgable in this area.

    Good luck with your decision....and have fun if you decide to remove the bilge/bow tanks...it's a fun job, especially the bow tank!! Ya, right!:)

Walter 		SOLTARA	T37	 #170					   August 2001
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I thought I would forward this as it may be of interest to all.

From: Mtdilemma@ 
Date: Wed, 26 Sep 2001 
To: MASEPOXIES 
Subject: Are MAS epoxies FDA approved foodsafe? Are they impervious to Fuel (dies..)

John: 
    Mas Epoxy Resins and Hardeners are formulated using FDA approvable components.  This does not mean that our final formula has been FDA approved for direct food contact but it is a prety safe bet that the formed polymer would be safe for potable water storage etc.  Personally, I have epoxy water tanks and the water does not take on any funny taste etc., with exposure to the tank.
    Fuels?  Gas - definitely not.  Deisel is probably OK but I have to do a little testing to confirfm this for you.  I would be glad to do the work and get back to you with the information.  I usually recommend Ameron for fuel and chemical resistant formulas as this is what they do.  We are generally considered a structural resin group. 

Thanks, Tony

Forwarded by John Reynolds							   August 2001
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  The tank can be repaired with MarineTex.  Get some plastic corner protectorsm from a wallpaper store and cut to the desired length. Mix the marineTex and butter the plastic angle. Press the buttered angle in the corners inside the tank and cure. It would help if he can pressurize the tank to a few pounds while it is curing.  I have used this method and it works well.

Tom Cagney							  	        November 2001
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Dayton,
   We have a 50 gallon polyethylene water tank in the bilge (our fuel tank is under the vee berth in the bow).  Fifty gallons is generally adequate for a 4-day trip with 2 guests. That allows about 3 gallons per person for food, washing dishes, sparse shower.  If there are two of us, we make do with somewhat less, but still need at least 2 gallons per person per day. I have yet to install a salt water pump in the galley for washing dishes, etc. For longer trips, I plan to install spare tanks under the berth. We also routinely store several gallons of water for emergency, in the event that our main tank runs out, or becomes contaminated.

   I had previously asked about other people's views of using polyethylene water tanks, but received no comments. Are there downsides to these tanks for drinking water? They should last a long time, yet everyone seems to shift to stainless or aluminum. Polyethylene is hard to repair, but not subject to corrosion.

 regards, Harvey								     April 2002
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Harvey,
   My new water tank in the bilge is 48 gallons, down from the original 80 gallon SS tank.  It measures 12" X 20" X 48".  I was loathe to sacrifice 30 gallons of tankage, but I was more loathe to not have good access to the holding tank, bilge bottom, and under side of the engine.   I also figured that I could squeeze in an extra 30 gallon tank somewhere below one of the berths if I really wanted the extra water.

Dayton Eckerson								     April 2002
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   We have a V-42 (hull 166) "Sunday Morning" and last year replaced the water tanks.  They occasionally made noise when filling or drawing down but not often.  Both tanks had rust lines where visible and one leaked very slowly.  A dry bilge is important to me so we made the decision to replace after researching fixing options.  We used SS from American Tanks in San Diego and are very happy.  We have slightly more tankage than with the old.
 
  Van Anderson 							         September 2002
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    We just bought a V-42 (hull # 162) and have the first of many questions to come.  We've noticed that the water tanks are "flexing" quite often when running water.  It sounds like the tanks have thin walls and as water is drawn down the sides flex.  This doesn't give us a warm fuzzy about the strength of the tanks.  Has anyone had similar problems and have a solution (other than ear plugs)?
 
Roger McClintock		"Weekend Pass"			        September 2002
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Jeff, 
    We have an aft cockpit V-42.  Before replacing the water tanks, I tried everything to repair in place - JB Weld, two-part coatings, etc - nothing worked as you need complete access to tank interior to repair correctly.  I hired American Tanks in San Diego to replace them.  Both tanks were cut into several pieces for removal so NO damage at all to cabin sole or structure at all.  They built new SS tanks - 3 new ones to replace each tank, inserted back in place, connected them all together and presto!  New tanks, no damage, no more rust in the water.  We are very happy with American Tanks.
 
  Van Anderson 							        September 2002
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   We have a V-42, hull # 177.  When one of our tanks is totally full, it will occasionally "pop" when one steps in the right place on the cabin sole until some of the water is out.  The top of the tank tends to bulge up just a bit, placing it in direct contact with a cross member of the sole, which must deflect just a bit when you step in just the right place, "popping" the tank top.  Once we use a couple gallons of water the popping stops.
 
Bill Rohde								        September 2002
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Van,
    Was it a big deal to get the old tanks out and the new in? I can't see now to do this (when needed) without cutting the timbers supporting the cabin sole. 
 
Paul Cassel  	V42	Romanza					        September 2002
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    We cut them and removed them in pieces.  The new tanks were 3 tanks per side and built to fit thru the largest opening we had in the floor without having to cut any timber or do any damage at all.
 
 Van Anderson	Sunday Morning	 V-42			 	October 2002
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Van,
    Thanks for the info. I'm surprised that you could fit sufficient tankage to both fit in between the floor and still be large enough (even 3 x 2) to get that capacity.  I think the group would find it of value, and I know I would, if you posted the design of those tanks on the ftp site. At this point, it looks like my tanks are perfect, but one of those bothersome worries I had is if I'm wrong and they're not. 
 
Paul Cassel									October 2002
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Coleman,
    I'm really not certain why the marine industry does not follow the aircraft industry in treating aluminum.   The best "home treatment" of aluminum is to wash the outside of the tank with phoshoric acid.  Then treat with alodyne and paint with a zinc chromate primer.  This treatment will prevent future corrosion.  The zinc chromate will prevent corrosion even if the tank is scratched.   All the interiors of "Navy" aircraft (check at any airshow) will reveal the "pea green" color of zinc chromate primer that was used on the aluminum.  
 
   I looked at many Island Packets prior to purchasing a Tayana, and I was always amazed that these boat had untreated aluminum tanks installed.  
 
Products mentioned can be purchased from aircraft spruce...
http://www.aircraftspruce.com/index.php
 
Some further info on alodyne and annodizing.  (Annodizing is a commercial process.)
http://www.matronics.com/rv-list/hovan/tips/AlAnDef.html
 
John Hovan	s/v Celtic Dream					        November 2002
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     I think I raised this question once before, but can't recall receiving an opinion - What are the arguments, pro and con of using plastic tanks for either water or for fuel? We have a thick polyethylene water tank in the bilge. It is only about 50 gallons, and I am thinking of adding an additional 50 gallons either under the settee or in the aft lazarette. The advantage of putting it in the lazarette is that I might be able to install it close to the midline, thus not affecting the balance.

   I also recall sailing on a number of boats with plastic fuel tanks. What would be the downside of replacing the iron or corroding aluminum tanks with plastic ones?

Harvey 									January 2003
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   I have been waiting to discuss this but now seems like a good time. Over the holidays, we pulled our bilge drinking water tank. It had a few holes we thought, so a winter removal and patching seemed in order. During the process of removal, we discovered the tank had a few more holes than we thought. Mostly over the last 10 years the boat was not well kept and sea water, rain and/or holding tank extras were allowed to accumulate and were not attended to regularly. The holes in the tank allowed the water to fill the tank and remain there. IT was full of rust and black gummy bilge water.

   So, I am using the tank as a model and have decided to build a bilge, drinking water tank from glass. We considered plastic and stainless, but the custom building of the tank seemed to be just too expensive for us. I am also going to space the tank off of the bottom of the bilge which is not flat. I think about one inch will allow water and stuff to flow to the sump. I read PVC pipe was used on one tank. PVC pipe becomes brittle and cracks over a period of a few years.  After removal of the tank, I used engine degreaser (safe for rubber hoses and fiberglass) to clean the bilge. This left the bare fiberglass. Water has almost stopped seeping from the glass now. When this stops, I have interlux bilge paint to put on a couple of coats. 

    While I was in there cleaning and noticed the 24 year old head hoses and sump hoses were brittle, cracked and/or soft. These are being replaced. I found the hose connections to the holding tank are accessible partially from under the floorboards and partially from the engine compartment. So we are doing this now. We will also be replacing/adding conduit in the bilge and taking out the glassed in gray water tank next to the bellows pump.  We will replace the tank with a "tray"  which will have a float switch connected to the existing Par pump. 

Joe Sprouse		Sojourn						 January 2003
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    Isophthalic polyester resin, I found, is FDA approved. A guick cure of regular polyester is acceptable (raising the temp of the tank to 145 degrees +/- for a couple of hours). There is also a polyester resin that can be used in diesel tanks but not for gas tanks. I was told the ABYC says Stainless tanks for diesel are limited to 30 gal. The ABYC has set several standards for aluminum tanks also. Most of them are designed for long life of the tank IE the type of aluminum, gauge and how it should be mounted.

Joe Sprouse									 January 2003
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    I would try to stay away from using any type of plastic for drinking water.  The chemicals (plasticizers) eventually leak into the water and are carcinogenic.  Plastic might be a good solution for diesel.
 
"Captain" Kirk								 January 2003
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    My experience was the pressure was enough to scour the tank to clean steel. No degreaser needed.
 
Joe Sprouse	Sojourn							February 2003
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John and Mark,
     Thanks for your suggestions and shared experiences.  A pressure washer has been located so we'll give it a try next week.  Did you use a degreaser of some sort or go with only the water?
 
Roger McClintock	"Weekend Pass"	 V-42 				February 2003
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    Went down to the boat Saturday intending to get some sanding done.  As always, one of the first things I do when I've been away for awhile (two weeks this time) is to flip on the bilge pump and note how long it takes before it sucks air.  It pumped and pumped and pumped and pumped.  My bilge was FULL of water. **&^*^*

    A quick inspection of thru hulls and packing gland failed to show up any leaks and the now empty bilge didn't seem to be filling back up.

    When we bought the boat a year and a half ago, it had a single electric bilge pump with the float switch mounted near the top of the bilge. Since this is a ship’s function for which I feel redundancy is necessary, I soon purchased another pump and float switch, but never got around to installing it.  The good news is that it is now installed with the float switch as low as I could get it and plumbed in to a new thru hull above the waterline.

   The bad news is that we've developed a serious leak (13 gal/ hour) in our fresh water tank.  I'm not sure where it is yet, but at least the tank, though large and no doubt heavy and cumbersome, is easy to access.  It's one of those that are in the bilge in the main cabin.  It even has a lifting ring welded onto it.

    The surveyor suggested that if it ever leaked, we consider cutting the top off and just put one or more bladder tanks into it.

    Has anyone ever done this?

Dan Best    B-2/75    1977-1979    Tayana 37    #192   "Tricia Jean"   	     June 2003
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    I don't mind share what my new aluminun tank cost especially when you ask so nicely.  I purchased it from Florida Marine Tank and, with the exception of the somewhat handmade nature of the inspection plates, I'm very satisfied with it.  The cost was $900 which was about $125 more than what I had quoted initially because I choose to upgrade to 3/16" as opposed to the standard 1/8".  The tank holds approx 87 gallons and weighed about 100lbs dry.  I have FMT actual drawing of the final dimensions but I haven't uploaded it yet.  I did upload some pictures and the drawing I provided FMT for the estimate and construction.

files at  ftp://tognews.com/Tortuga_T37/NewFueltank/ 

John Ware									       June 2003
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Aloha:
    An and I installed a 39 gallon bladder-type tank under the starboard settee. It was one of the easiest modifications I have done to the boat!  Our decision was predicated on several factors.  First, the installed centerline tank has problems.  It is no longer in the bilge (see exchange below). Second, we are moving on board in about a month and needed a quick solution to water on board.  Third, none of the decent sized, hard plastic water tanks available at West Marine would fit very well anywhere except back in the bilge but we want to keep that clear to install a new tank (fuel or water, haven't decided yet.)  Fourth, we plan to install more potable water tankage later, but have not decided on materials or location.

    During an earlier thread on this subject, someone wrote that they planned on building a tank from polyethylene resin and fiberglass.  Any progress on that?  During my little bit of research, I could not find a source for FDA approved resin to build fiberglass water tanks.  In fact, this web site: http://www.westsystem.com/ewmag/18/pdf/tanks.pdf for West System products recommends not using fiberglass resins to build water tanks.

   I have a mig welder and have considered grinding back and welding the bad spots in the SS water tank I pulled from the bilge. Any comments on all of this?

Bill and An		S/V Kracker	 T-37		Pearl Harbor, HI   	      June 2003
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    Took my tank out by myself.  Disconnected everything and lifted one end out of the bilge.  Then stood it up on end.  Slid along the cabin floor with old piece of rug underneath.  Put some rug up the companionway and leaned the tank towards the hatch.  Since my boom is off, I attached various lines and halyards and blocks around the boat cockpit and used the sheet winches to gain the leverage to pull it out.

    Still sitting in cockpit.  Leaks from lots of pinholes on welded joints. Thinking about grinding back and welding.  Temporarily put in a 39 gallon bladder in the port settee.    Someone was making a fiberglass water tank.  Any progress or thoughts on that?

 Bill and An		S/V Kracker		Pearl Harbor, HI		       June 2003
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    A number of years ago, I used a company in Tustin California for a holding tank.  I just checked their site and they are claiming over 400 tank sizes and shapes available.  Another plus is that they can install the inlet and the outlet anywhere on the tank to make the tank work from any direction. I found them at Yahoo at Ronco Plastics. You might give them a look

Ted Tomasek		Kailani  	V-42					    June 2003
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    Dennis, I do not think painting the SS tanks was the thing to do.  SS maintains its anti-corrison capability by being exposed to oxygen.  Cut off the oxygen suply and SS will rust.

Joe Sircely  	 Pegasus							     June 2003
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    OK group..this one should be worth a few replies. We purchase our T-37 three years ago. The starboard water tank was replaced at that time with a plastic tank. We have only been offshore once (bringing it home). The rest of the time is in relatively calm waters. Our plastic tank failed in three places on top (large cracks perpendicular to long axis).

    I am in the process of repairing rotted wood, teak, etc. because of this failure. I would appreciate discussion on pros/cons of plastic vs. stainless....disregarding price!  Is plastic failure in 3 years normal????

Mark & Joan		s/v Querencia, 	T37			      September 2003	
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    With normal thickness construction that is constrained, plastic failure should not be common in 3 years service.  The difficulty with 'plastics' is the the structure MUST be adequately supported and constrained to prevent flexing and buckling, etc.  The difficulty is that such tanks should have internal baffles to prevent shock and fluid impact; most polyethylene tanks dont have such baffles and those that do are applied with poor engineering practices.  Such tanks are usually 'roto-molded' and don’t have internal baffles. Polyethylene is probably the BEST material for potable water from a chemical compatibility and cleanability viewpoint.  Continual sanitization will take its "toll" on a metal tank.

    Polytanks *can* be repaired but you need to find someone well versed in the "art of polyethylene welding" ( might want to add baffles at the same time).  A well constructed stainless tank ... is going to be expensive, especially if you can find an artisan/technical welder who won’t include a lot of 'weld laps' and other intercitecies that will promote stress corrosion.  Chlorination of your potable water will attack the stainless over the long haul. With an unlimited budget, I'd opt for Polyethylene *with baffles*.

Rich Hampel								        September 2003
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    Fortunately when I broke a hose barb off one of the poly tanks on my Norsea, I did not know that I needed special skills to weld it.  So my amateur repair lasted about 5 years until I sold the boat...  The break was my fault when I got too aggressive about removing a hose clamp.  
 
    I was told how to fix it by Jim Jessie who is a surveyor in the SF bay area.  Jim had run a boat yard for years.  He said to "weld" it with a soldering gun....
 
    I cut a hole in the top of the tank with a saber saw.  The hole was the size that could be covered by a plastic deck plate when I was finished.  I cut the polyethelene disc from the hole into a couple of thin strips and melted the plastic into the joint I had broken.  It worked like a champ. 
 
    The only innovation I had to come up with was a way to breathe while working in the tank...The fumes and smoke produced by the welding process were pretty bad.  After considering several ventillation options, I finally settled for using my scuba tank and regulator for the 5 minute job. 
 
Welding in baffles would be a much bigger project. 

John Lewis								        September 2003
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    Go to www.ronco-plastics.com for rotomolded, etc. poly tanks.

Rich Hampel								        September 2003
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    Further investigation after getting tank out revealed several things.  The top was cracked in three places on top. the edge that had been thermally "bent" into a top/side corner had failed in several places, looks like stress cracks.  In researching and talking to several boat brokers/dealers, they have stated that they would not recommend plastic, as they have seen several cracked before. Let me know what the "group" is thinking, I NEED INPUT to make a decision. Getting prices locally on both.

Mark		S/V Querencia		 T37 				        September 2003
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Marco, 
     It can be done. I've never done it on the tanks in the boat, but have tested oil tanks on land (required by environmental reg's in VA). You'd have to block off all of the connections to and from the tank. Because of the unstayed flat surfaces, you need to use a very low testing pressure, 1/2 psig max. Square tanks are not designed for any internal pressure, and will distort easily or even open up like a tunafish can if you put too much pressure on them. If your tanks are glassed in like ours are, if you round out the tank, you'll break the tank loose from the boat. Not good. 
 
    Instead of pressure testing, I would open up the tanks, clean them out well, and look for any pitting from the inside (pay attention to the corners and weld seams). If you don't have rust stains coming out from underneath, you probably are ok on external corrosion on the bottom. I would treat the surface rust with Ospho, and repaint. I did this last spring using Pettit "trailercoat" paint. It seems to be holding up well.
 
    The trick to not having your tanks corrode, is to keep water off them on the outside and make sure that any water that gets in is removed promptly. Keep the tanks as full as possble to avoid breathing and condensation.
 
Frank Timmons    V-42 	Magic Dragon    Deltaville, VA    		February 2004
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    Well, I have a question.  Recently, my wife and I purchased a T-42 CC.  I know there is a holding tank forward adjacent to the forward head.  But is there one aft for the aft head?  Any problems with the head lines going forward getting clogged?  Any idea how large the forward holding tank is?

Jon 									    	 October 2004
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Subject: Leaky fuel and water tanks - need guidance

Kendall,
    There is a product called "Proseal" that is used to seal aluminum airplane wings.  It's sold by Aircraft Spruce.  It may work on other materials besides cast iron (I would check before buying).   It's kind of like a silicone or caulk in consistency.

 http://www.aircraftspruce.com/catalog/appages/prosealant.php

 or here for the brand name stuff... 
 http://www.aircraftspruce.com/catalog/appages/ps890.php

 John Hovan	 s/v Celtic Dream						October 2004
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    To replace my 100 gal water tank in the bilge of my T37, I went with two stock Ronco-Plastics stock tanks, #B157 and #B347.  These are 'rectangular' and do not use all of the available ' trapezoidal' space in the bilge area.  I am going from 100 gal to 70 gal, but I am installing a water maker and hope that I will be okay.  I am hoping to use the extra bilge space to store some heavy stuff, like extra anchor chain.

    I went with Ronco, http://www.Ronco-Plastics.com , because all of their tanks are roto-molded, which gives a strong tank.  Ronco is highly recommended, and their stock tanks are inexpensive.  You can get a custom tank made, but it will cost much more.

    A previous member of this list, Dan Best, replaced his water tank with two custom made tanks from Duraweld, http://www.dura-weld.com/ .  I think he ended up with two 50 gal tanks.  As the name implies, the custom tanks made by Duraweld are 'welded'.  I believe that the seams can eventually crack, at least, that is the scuttle-butt.  I spoke with them and they said that they could find the drawings for Dan Best's tanks. I almost went with them.

    Another reason that I went with Ronco is that they are in Orange County and I can go up and pick them up and supervise the installation of the fittings and such.

Dan Baker	Che Bella						          November 2004
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Dan,
   T-37 leaky tanks - looking for replacement ideas.  Did you find a stock tank to replace your 100-gallon leaky water tank?

Kendall Bailey 	Dana Point         				      	         November 2004
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Subject: [tayana] Leaky water tanks - need guidance

    The green wire connection to the stainless water tank below the cabin sole has come loose, causing tank to drain into bilge.  Looks to be either a ground wire of perhaps remnants of an old sensor.  Hole is right at bottom of tank, aft end with green wire hanging out.   Looks like there is one more "probe" about 1 inch away for the hole.  Found green wire with screw attachment and black rubber cover connected.  Tank inside is clean and shiny, no rust. Have others had this problem?  Is there a way to plug the hole from the outside?  Again - need your guidance on what works.

Thanks, Kendall Bailey	 Dana Pont, CA       			         November 2004
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Regis,
    You listed many good tips. When I started cleaning the interior of my 25+ year Tayana I took a hose right in with me and cleaned the inside of the hull and was amazed at all the junk, dirt, and debris that ended up in the bilge. I scrubbed every inch that I could reach with a hospital grade disinfectant cleaner that works on gram - and gram + bacteria, mold, etc.  (Johnson Virex 256) and it helped out tremendously.

    Subsequently, I removed the diesel fuel tank from the bow and the fresh water tank in the bilge and still found saw dust, old screws, bits of wood, coins, etc. that were lodged underneath. I have literally touched every inch of the boat in cleaning it.

    I removed all the old hoses, etc., and they reaked of odor. I agree that the biggest contributor to odors is old fuel and sanitation hoses. Once old hoses are replaced and the interior is really cleaned and kept clean on a regular basis, odors should be minimal.

John Keefe	CT37 	No.63 	ODYSSEA	Youngstown, New York       November 2004
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    Permeation of liquids through polymers (and some metals) is well known fact in the chemical process and biopharm industries.   What 'drives' the flow is simple chemical equilibrium and vapor pressure.   The structure of a polymer on a sub-microscopic level has intersticies or 'holes' and these are all connected to a statistical degree.  The vapor permeates through the 'holes' until the equilibrium is reached when the vapor 'condenses' into a liquid.  This phenomenon progressively continues through the polymer until the fluid/vapor is noticed on the opposite surface of that which is in contact with the liquid fluid. The higher the vapor pressure, the greater the 'flow'.   Of course this a is a very slow process timewise and is dependent on the size of the molecules migrating through the molecular sized 'holes' in the polymer ... and the rates of 'transmission' continue until equilibrium (steady state) are reached and the polymer is internally saturated with the fluid that it was thought to contain. Once saturation completes all the way through the thickness of the polymer, you can detect the fluid molecules that were supposed to be contained on the the exposed side - just be patient.

    This is just simple osmosis on the molecular level that is 'driven' by vapor pressure.  Its probably the transport mechanism that causes osmotic blistering in fiberglass boats ... and it doesnt matter if the water comes from inside or outside the boat.

    As regards anchor lockers, bilges and other smelly places on a boat what you are probably smelling is the decomposition of microorganisms either picked up by the anchor rode or were growing on surfaces when supplied by high water vapor/'humidity'.  Bleaches, etc. only kill such organisms and leave the cellular debris to rot and stink and become the nutrient sources for successively arriving microorganisms.  For smell removal, periodically use highly caustic solutions (dilute lye solutions, detergents that contain sodium silicates or acidic solutions that contain "peracetic acid") to dissolve the cellular debris.  There is personal danger awaiting from some of the species of molds and mildews that grow on the hidden humid dark and warm surfaces inside a boat: including the 'black mildews' that are extremely toxic to skin and your respiratory system.  As regards molds and mildews, you WILL also find them growing INSIDE the potable water tankage .... its the black staining inside the plastic hose, tankage, etc.  How these molds and mildews got inside the potable water system was by the unprotected/unfiltered tank atmospheric vent.

Rich Hampel								         November 2004
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    I'd leave the rust in the tank - as is.  Any acetic chemical you put in will perhaps further weaken the already corroding tank, especially any welded areas.  Rust won’t hurt you. You can put a cheapy particulate filter just downstream of the pump to remove visible particulate.  Suggest you go to Home Depot, purchase a simple 10" polypropylene "Ametek type" (arranged for flat gasketed 10" long X 2.75" diameter filter cartridges) for about $40.00 and a cheapy 10µM 'particulate' filter made of all polypropylene.  A 10" filter typically hold about 50 to 100 grams of crud (a lot of crud) before you need to change.

Rich Hampel								        November 2004
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John,
    The active ingredient in Barkeeper's Friend is oxalic acid. That's a real no-no for use near potable water if you want to have functioning kidneys afterwards. It's the equivalent of drinking radiator fluid. It's great for exterior stuff; just be sure to wear nitrile gloves when using it, as oxalic acid is absorbed through the skin as well as mucous membranes; if you detect an odor of aerosolized material, wear a respirator.

    I suppose anything he uses would be harmful to health. I'd insist that the tanks be removed from the boat when treating and rinsed, rinsed, rinsed, so there is no possibility whatsoever of any of this stuff finding its way into the plastic plumbing where you will never ever be able to remove all traces.  It's not something I'd want to do, personally, without the consultation of a chemist.

    From what I've seen reading ingredient panels all "metal polishing" compounds contain either oxalic or phosphoric acids, with the occasional additional muriatic acid thrown in. I'm sure Rich has much more knowledge of this than I do. They are all equivalent in function, but vary greatly in price. IME it's not uncommon to look at someone's cleaning box on a boat and see a dozen different brand names of stuff which are functionally identical.  I remember reading a great article, I think it may have been in "Gentlemen's Guide to the Caribbean", which espoused buying the five main ingredients for cleaning supplies (oxalic acid, phosphoric acid, muriatic acid, vinegar, and bleach) in as strong a concentration as possible, and then diluting them to suit the task at hand. They are both much cheaper this way and take up less room on the boat. In my case I buy oxalic acid in generic powder form and dissolve in water or make a paste as needed; it's about 5 - 10% of the cost of formulations like Barkeeper's Friend, Marine Brite, etc.

    Note that the expensive "two part" teak brighteners are simply oxalic acid followed by bleach (never mix them together!)

Charlie Freeman							          November 2004
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Subject: RE: [tayana] Water Tank Rust Clean Out

    Anyone have any good ideas of what to use and how to clean out a rusty bottom on a SS water tank? This appears to be only, ha, only, in the bottom.  Also what's a good way to clean the tops of the SS tanks as they are somewhat rusty too.  Thanks for any help.

Walter Alexander	 TOUCAN   	V-42cc			         November 2004
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 Walter,
    I have been thinking about your question and the only thing I can think of, and I'm really not sure if this is a good idea in a potable water tank, is to use "Naval Jelly" which you can get at Home Depot, etc.  I know it takes off rust.... but......maybe not such a good thing to do.  Sorry, I can't be much more help to you but I have no background in metals or chemical tank cleaning, etc. I think you have stumped us all on this one.

Regards, John Keefe 		CT3	7 No.63 ODYSSEA  		         November 2004
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    I believe Barkeepers friend, found at most local grocery stores, would be the best product to use.  Thoroughly rinse afterwards.

John Hovan		 s/v Celtic Dream				         November 2004
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    My water tank vents through a U-shaped stainless tube into my head sink.  Maybe that was where yours went at some point.
 
Dan Baker	 Che Bella 							February 2005
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    VERY BAD idea – this can be a source of retrograde bacterial infection of the tankage.  Just think of all the Staphlococcus aureus, E. Coli and other 'nasty' micro-organisms in the head and inches away from the vent at the sink!   Why would you want these growing in your tankage?   To assure a clean tank system, the vent should terminate in a bacterial blocking device to prevent aspiration of molds, mildews, bacterial, el-forms, and other lifeforms that make you sick, give you fever ...... give you the 'trots'. 

    All you have to do is wrap a fist-sized wad of bandage cotton over the vent end, keep it dry, and change once yearly.  The most common toxicant found in boat water systems are stochybatris and aspergillis molds/mildews and they can be VERY toxic ..... its the foul dark-green shit that grows inside all the hoses, tanks, etc.  If you're sensitive, the stuff can kill you. 
 
Rich Hampel									February 2005
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Hi Andy,
    Are you SURE you have Aluminum tanks???? much of the low grade stainless used on boat tanks ‘looks’ like aluminum. What is confusing is that many use stainless with a sandblasted surface .... very confusing. 
 
    If you do have aluminum there are several (time consuming) possibilities .... chiefly the usage of hydrogen peroxide but your going to need LOTS of hydrogen peroxide.  The concentration needed with peroxide (30,000 parts per million) will either involve very concentrated (very dangerous) OR a huge amount of the ‘drugstore’ stuff. I suggest a thorough mechanical scrub followed by several good ‘blasts’ with a hose to knock off the biofilm, then rinse the tank. By rinsing (after scrubbing), I mean using many cycles of hitting the walls with a ‘little bit’ of water from a hose. then completely draining each time; I dont mean completely filling and emptying once or twice. THEN, when youre quite sure the biofilm is gone, then add a Gallon or two of drugstore peroxide to a few inches of water in the tank bottom, pump through until the mix hits the spiggots, then shut down and let soak (4 hours minimum with peroxide). 
 
    Just as with ANY sanitization you MUST mechanically remove the 'bio-film'. To  destroy an established biofilm without scrubbing, repetitive sanitizing cycles are usually required. The initial chemical exposure (Chlorine, peroxide, etc.) may/usually only kill the top layer of biofilm. The disinfectant will also destroy the gel-like sugars (glycocalyx) or slime which is the “glue” that holds biofilm bacteria together and to the pipe wall. This weakens the biofilm structure. For that reason, it is a good idea to follow any chemical disinfectant exposure with a high-flow flush. Fresh disinfectant is then reintroduced to the tankage/piping to kill the next bacterial layer. If the tank/piping has no access for mechanical cleaning, then this sanitization/flush cycle may need to be repeated several times on consecutive days until the accumulated biofilm has been removed. For a well-established biofilm, 3-10 cycles may be needed. If you knock down the biofilm with mechanical scrubbing, then you probably only need a single shock sanitization to accomplish a low residual microorganism count. Once the biofilm is gone, the use of low levels of disinfectants – chlorine (not with an aluminum tank) or peroxide, etc. will keep the ‘fauna and flora’ down to fairly acceptable 'hygienic/potable' levels.
 
    I am simply AMAZED at the gross misinformation written and published about 'sanitization' of 'boat water systems'. I can only assume that these 'authors' simply misread or misperceived sanitary specifications/recommendations and never really ever actually did a bio-assay/culture after they were finished to validate their 'cookbook' recommendations. You CANNOT expect to have a sanitized system by simply dumping in a certain amount of certain chemicals, waiting a prescribed time .... and then assume that evertything is 'hunkey-dorey'.  THE MOST IMPORTANT ITEM in sanitization is REMOVAL OF ****BIOFILM****. The simple and 'most elegant' test is to rub your fingers on the tank walls or the inside diameter of the hose .... if SLIPPERY then you have a biofilm. Once the film is GONE then you can sanitize.  Nothing beats scrubbing with soap and water!!!!! 
 
Rich Hampel									October 2005
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    Hans Sasse in the Houston area was indeed the fabricator for Soltara's water tanks according to the TOG FTP site listing.  If Hans is a 'local' to Kemah area perhaps a telephone call, etc. would answer my questin as to the manufacturer or source of the material (pre-pegged polyethylene sheet with integral cloth backing)........ so that I can put a proper epoxy/polyethylene liner in my blown-out 100-gallon aluminum bilge water tank !!!!  An epoxy liner by itself, I deem, would yield too high an 'extractables' to be suitable for potable water 

Regards, Rich Hampel								October 2005
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John,
   Many thanks for the hint. I may just do a 'test drilling' down into the 'membrane' that surrounds the ballast - just for a 'look/see'.  I didn’t perceive any off-gassing permeating through the wall; but, now that you mention it, I'll put a Saran 'patch' on the wall, etc. for a bit of time, then take a 'whiff'.
    For my aluminum tank, I plan to just cut the top off and lay-in an FDA listed for potable water epoxy fiberglass liner, coat the exterior bottom to prevent/retard corrosion, seal the top and put it back in.  With the price of stainless these days, it would probably be cheaper to buy a new boat than a new stainless tank. I'm still looking for the material that Walter Bruj (Soltara) selected to line his new tanks - polyethylene sheet prefaced with fiberglass as that would yield the least amount of 'leachables' into the potable water.  

The Garboard drain is 'doable' and probably a great benefit. I'd go with Monel metal for the plug.  It’s going to be difficult to drill close and parallel to the floor of the bilge bottom and be close to the bottom with a hand drill. I envision you in there with a hand-cranked push drill to get the correct pilot hole height from the bottom floor, then drilling back in from the outside with a power tool.  Just be sure that you don’t break into the FRG membrane that surrounds the ballast ... at least keep the hole dry until you inject epoxy if you do penetrate as you don’t want ferric rusting to begin in the ballast cavity as that will be the absolute 'beginning of the end' of your boat. 

best regards, Rich Hampel						          November 2005
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Rich,
    I split PVC pipe in half lengthwise and glassed the strips to the bottom of the bilge to support the new tank I had built. The tank is an inch shorter in height to compensate for the half-height of the PVC pipe. If I get water in the bilge forward, it should have no trouble running aft beneath the tank. The tank shouldn't even get wet unless the boat takes on a lot of water. Once the bilge is pumped dry, air will be able to circulate under the tank again. I'm currently replacing all the piping on my boat and have been finding lots of construction debris (in a 24-year-old boat) outboard in the upper bilge areas beneath the galley, saloon and chart table.

Sue Canfield	      Aeolus	   T-37 		#305		          November 2005
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    Our T-37 had been refitted with aluminum water tanks:  2 in the bow, 2 in the bilge.  They had the aft bilge tank repaired about 6 years ago when it developed a pinhole leak in the bottom.  It evidently had corroded (??) after being in contact with the salt water in the bilge.  As a remedy, I placed deck blocks under the tank to allow water/air flow around it.

    Last weekend, I pulled the tank, and it looks like it's getting pitted again.  Other than replacing the tank with a plastic one (lots of $$), is there a suitable coating that could be applied to the outside of the tank to protect it from salt water and other stuff in the bilge?  Would a coating like "rhino-liner" work?  Thanks for your input.

Steve Abel	SV Victoria Rose	Tayana 37    #384 			February 2006
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Subject: Re: Protecting an aluminum water tank

   Coatings are great .... until you get a pinhole in the surface and then the corrosion is usually 'much worse' than without such a coating.  Aluminum tanks need anodes --- typically magnesium anodes, just like your hot water heater!!!!!  

    BTW - The main problem with aluminum tankage is that chlorine sanitization is contraindicated because of the chlorine/halide attack on the aluminum. For aluminum vs. sanitization you need lots of hydrogen peroxide to do the sanitization maintenance job.

    Stainless will cost a minor fortune but will better withstand chlorine sanitization ..... still needs an anode - IMHO.  Probably the best/cheapest is what was done on Soltara (Walter Bruj) with a polyethylene lined fiberglass tank .... can use caustics to clean and won’t be a problem with corrosion. You just need to use foo-grade resins (and be able to find the special 'resin wettable' polyethylene that his tankmaker used .... and which apparently no one else in the world has).

Rich Hampel  	T-37	 #423 	"Aquila"					February 2006
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    Per American Boat & Yacht Council (ABYC) standard H-23, aluminum is not an acceptable material for tanks in contact with potable water. Whoever installed your boat's aluminum tanks was obviously ignorant of marine industry standards. I wouldn't advise spending good money in an effort to extend the service life of aluminum water tanks. Instead, buy new ones made of stainless steel or plastic.

Sue Canfield 	     Aeolus	 T37	 #305					February 2006
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    You can pay now or pay later when you sell the boat. A good pre-purchase surveyor will note the aluminum tanks (and their condition) and likely adjust his/her opinion of the boat's fair market value accordingly.  Consequently, the prospective buyer may lower his/her offer or, perhaps, buy a different boat.

Rich, when did Ta Yang install aluminum tanks? I haven't seen any on the Tayanas I've surveyed.

Sue Canfield	  Aeolus	 T37	 #305					February 2006
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    Bert at www.seafabtanks.com is building us a new custom 100-gallon bilge tank now.  We shoud pick it up sometime next month, I'll let you know how it works out.

Jim Grant	T-37	 # 370							February 2006
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Jim,
    How does the 100-gallon tank fit into the bilge.  I'd consider this option instead of the 2 smaller tanks currently in the bilge.  The two smaller tanks are placed in between the 2 removable "floorboards" and the teak grate (at the bottom of the companionway).  The tanks extend from just in front of the engine to about 18" in behind the compression post.  Would the retro-fit of a 100-gallon tank require a bit of sole removal and woodworking?

 Steve Abel	SV Victoria Rose	Tayana 37 	#384			February 2006
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    Bert at Sea Fab seems very nice and I'm looking forward to getting my tank.  With reference to how it fits in the space, I'd have to see your sole.  I think mine is pretty standard.  You open the two first floor boards and there's the tank.  My wife has all the dimensions.  If mine fits after Bert builds it, I'm sure everyone could use the drawings we sent him.

Jim Grant									February 2006
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    I recently read through the rules for the Bermuda Ocean Race (scheduled to depart on June 9 from Annapolis this year):

"3.21: Permanently installed water tank(s) dividing water into two compartments with permanently installed water delivery system and a separate Emergency water container for 2.4 US gallons."

(Rules are based on the US Sailing Racing Rules of Sailing and the ISAF Offshore Special Regulations Governing Offshore Racing for Monohulls.)

    I was reminded of my discomfort when I headed offshore with four souls (plus myself) and 100 gallons of water in a SINGLE tank and how I had wished that I had a different tankage arrangement.  I mention this as I've read the recent emails with a jaundiced eye.  I strongly believe that multiple water tanks (ON CENTERLINE) are better than a single tank.  Furthermore, I would STRONGLY suggest that those of you with a multi tank option should select that option and those of you that already have multiple tanks should retain those tanks.

I was forced to carry case upon case of bottled water (more weight in the bow...the "garage") as a means to mitigate the potential risk of fouled water in my ONLY tank.

I have found the presence of a single water tank in an ocean going yacht of this stature to be as ludicrous as the fuel tank in the bow.

 Tad McDonald								February 2006
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    I was confronted with a variant system on our boat when we bought it. The old water tank had been removed and a baffled polyethylene tank installed. But it was only 50 gallons, barely enough for a casual  4-day weekend with four on board.  The choice was to either remove it and replace with a 100 gallon, or add supplementary saddle tanks.  I found a Nauta flexible 37 gallon tank, and plan to install that under the port settee. My concern is about balance, since that puts about 300 pounds on the port side. We still have our 90 gallon fuel tank in the bow, and depending upon plans for future travel, may remove it and put the fuel tank in the bilge by converting the 50- gallon polyethylene water tank to a fuel tank, and adding a second saddle tank for water (possibly a 45-50 gallon) under the starboard settee. This depends upon the wisdom of using a poly tank for fuel.  Though this reduces the total fuel volume to 50 gallons, I could then add a small supplementary fuel tank for longer journeys. Seems like a juggling act, but it means that I will have two separate water and two separate fuel tanks, which reduces the problems of contamination.

regards, Harvey								February 2006
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Harvey and all,
    Considering the limited options on a T37, I think Traveler has a pretty senisble arrangement of tankage. We carry 150 gallons of water in two (factory original) 75-gallon SS tanks, one each located under the port and starboard settees in the main cabin. Our 90-gallon fuel tank is, alas, in the bilge (but for that matter so is the wiring at the base of the keel-stepped mast). Potential exposusre to salt water aside, it is low and on the centerline between the galley and nav station. So, additional weight ~ 1200lbs. for full water tanks is centered longitudinally; fuel weight is low as it'll go,  and we have no iron fuel tank in the bow, so hobbyhorse special effects are minimized.

    I agree with Tad - the old saw about putting all one's  eggs in a single basket is particularly true when considering the storage options for potable water offshore ------ watermakers, et. al.,not withstanding.

Sandra Blake	T-37	Traveler	Hull#328	Herndon, VA		February 2006
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 Ta Yang has never installed aluminum water tanks.  Always SS.

Neil Wineberg		Importer for Tayana Yachts &amp; X-Yachts	February 2006
________________________________________________________________________

    Then they outsourced the production of my boat as the water tank is Aluminum ... as I had to cut the 2 floor beams to remove it (no the beams were not 'keyed').  I also visited 2 T-37’s of the same vintage as my present boat in the Houston area ... both also with OEMN aluminum tanks. 

Rich Hampel									February 2006
________________________________________________________________________

Rich, 
    I guess Gibson Yacht in Houston could have special ordered aluminum tanks back then.  I can't imagine why but maybe he felt they were better than the SS.  I'm curious now so I will ask Basil

Neil Wineberg									February 2006
________________________________________________________________________

    It just plain doesn’t make sense to use aluminum versus water ... too many problems.  Although, with the skyrocketing world prices of stainless and basic polymers, aluminum becomes attractive ... even knowing that it is ultimately 'consumable/disposable'. 

    My boat definitely has an aluminum OEM installed tank and made from a cheap grade of aluminum. 

Rich Hampel									February 2006
________________________________________________________________________
Jim,
    I made contact with Bert at SeafabtankS.com and he was very helpfull. After much sucking of teeth, he came up with a price of $1431 per tank, with a 10% discount if I replace the 2 (port & starboard) at the same time. I think that this price, albeit steep, is representative of replacing the tanks with stainless and it should be a once only job (althouth even the Taiwanese SS lasted 24 yrs!). Thanks for your help, and if anyone else has the same underbunk arrangement and wants to retain 2 separate 70-gallon tanks, I'm happy to act as an intermediary to see if we can drive the price down.
Stephen 									February 2006
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    Considering the price of heavy duty polyethylene tanks that we use in the lab, this does seem a fairly steep price for water tanks.  Searching the web, West Marine, Defender US and other boat places, seems that they stock Todd Polyethylene tanks for about $175 for a 55 gallon unit. Perhaps if a group of people needing water tanks directly approached Todd Manufacturing, they could make up a bunch at an even more reasonable price. Flexible tanks are about the same. There are many manufacturers of fiberglass water tanks with relatively reasonable prices. What is the great advantage of having a pair of custom made steel tanks fabricated for $1,400 each? 

    I also wonder why not use plastic tanks for fuel, as well. If these plastic tanks are kept out of the sunlight, they can last for several decades, according to the bits that I have read. 

regards, Harvey								February 2006
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    Large tanks (all) need baffles to stop the impact of the contents surging against the endwalls, etc.  Rotomolded polyethylene tanks usually dont have baffles; hence, the need for custom fabricating (with baffles) .. at a monsterous price.
 
    'Bladders' without baffles are also destroyed by the same action (plus abrasion).  I had a large bladder holding tank 'get away' from me one time .... I instantly learned the functional definition of the medieval term: 'nosegay'.

Rich Hampel									February 2006
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Rich,
    The polyethylene water tank we have in our bilge is only 50 gallons, but has prominent baffles.

regards, Harvey 								February 2006
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    I am still looking for a curved water tank with pre-installed baffles to use as a water tank to be installed under the dinette bench. No luck. I have tentatively decided to go with a flexible/collapsing 37-gallon tank by Nauta. Lack of baffles bothers me. At present, we only have a 50-gallon polyethylene tank in the bilge. 

regards, Harvey			  					   March 2006
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Harvey,
    I had two, flexible Nauta tanks in my old Pearson 34 for water and two for waste. The the ones for waste were questionable, due to the odor.
 
    I changed both water tanks when I bought the boat, because it was difficult to get the bad taste out of them. They weren't expensive and the replacement was easy. One of my tanks was leaking when I bought it, so you need to make sure that they drain into the bilge. Mine were 25 gallons each, so I'd suggest that you buy smaller tanks and hook them together with shutoffs. That way you don't have to worry about baffles.
 
    My tanks were vented. The largest two problems I had was 1) overfilling and 2) getting the water out.  If you overfill the tanks, they bulge and can explode. The other is how to get the take-off fitting low enough to siphon the tanks empty. You need to have easy access to the tanks so you can watch them fill. 
 
    I have heard stories of successfully using flexible tanks for diesel while off-shore. They make good temporary storage. There is no reason why they couldn't be used for water in the same capacity.
 
Now the holding tanks, that's a different story!!!!

Bruce										   March 2006
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Hi James, Nick, Bruce, 
    The problem with our current setup is that the previous owner had replaced the original 100-gallon water tank in the bilge with a 50-gallon tank. The tank is polyethylene and seems in good shape. It has internal baffles. But it is a bit small at only 50-gallons. In view of cost and the various horror stories I keep hearing about metal tanks, I like the notion of polyethylene tanks. But I can't find a source for any tanks similar to the one presently in our boat, regardless of the size. 

    The notion of getting a flexible tank is only because I happened to find a new Nauta 37 gallon tank at a recent swap meet. My concerns are exactly the ones you have mentioned.

regards, Harvey								    March 2006
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Hi Nick,
    I am not quite so discouraged about the matter of tanks. Perhaps we can ask Neil about the possibility of Tayana making up suitable tanks and shipping them over. 

    John Lewis recently posted the CAD drawings for the dimensions of the tanks on his new T-37 Pilothouse. The dimensions seem to also match that needed for the regular T-37.  The CAD drawings were prepared by Basil at Ta-Yang, so we know that they are accurate.

    I also wonder if one of the U.S. companies that fabricate polyethylene tanks could make up a batch to our specs for some amount substantially less than Seafabtanks charges for one-off versions. Todd industries makes polyethylene 100-gallon water tanks for boats for about $180-$300. Unfortunately, they don't come with baffles and aren't the correct dimensions for the space in the bilges of T-37s. But perhaps they would make some up if we assembled a group purchase. 

    I have only looked into the tanks made by Ronco and by Todd. But there are a number of other companies that make water tanks. Another consideration would be to have them made of fiberglass. There is a type of fiberglass that is safe for drinking water. And... it would never rust or rot out! That is also the attraction of polyethylene tanks. 

    Yet another strategy that comes to mind is to buy several smaller tanks that can be lined up vertically next to each other in the bilge, e.g., (4) 25 gallon tanks. You can then easily build a manifold of PVC pipe and irrigation types of ball valves, and select the tank you want to use. This strategy has a number of advantages, including allowing you to keep a more careful check on water usage, and also if one tank becomes contaminated, it won't spoil the rest of your supply. (You could then even flavor one with lemon, another cherry, raspberry, and chocolate, so you would have "designer water flavors".) Since each tank would have only 25 gallons, you wouldn't need baffles. (Gee, I like this idea enough that I may see if I can find tanks of the correct sizes on the Internet.)

    You might also check out Don Casey's book "This Old Boat" (or some such title). He has a section on fabricating new water and fuel tanks. 

regards, Harvey							   	   March 2006
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    The S.S. water tanks Ta Yang now buys are very high quality, redesigned for the welds and most important, a better welder. When I return home (tonight) I have a few suggestions for reasonable local manufacturers that would be cheaper than importing from Taiwan.
Neil Wineberg									   March 2006
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Hi David,
    The CAD drawings of the water and fuel tanks in John Lewis's boat can be found at:
http://tognews.com/ftpfiles/Active_Transport/drawings%20of%20tanks%20in%20T37%20581/  However, there may be enough variation in the construction of these boats, that you should double check to be certain that these dimensions apply to your boat as well. 

regards, Harvey				 				   March 2006
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   On this subject, I have heard that West System suggests a method of coating the interior and merely uses the old tank for shape. While I have not checked this out, the source said that West Systems gave detailed instructions (using their products of course) and the favorable end result was done with tanks in place. If true, this might save a lot of time and $$ on this issue. You may wish to contact them to see if my source is correct.	
David svhegira							   		   April 2006
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    WEST SYSTEM is probably a good time and money economical method of refurbishing/relining a fuel tank. However, WEST does not have a material that is FDA approved for potable water.  For potable water tank linings, go to Interlux Marine Division and see (or do websearch) for their product "Interline, 925" .... suitable for lining potable water tanks.

Rich Hampel	Ty37	 #423 	"Aquila				   		   April 2006
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