It seems that my 1983 26 Sport Convertible outboard needs a new gas tank. The effects of ethanol and some sort of misguided repair attempt by, it appears, spraying the inside of the tank with gelcoat have done it in. So, I have been reading the old posts on this board and talking to folks. Most of the folks I have spoken with say that Aluminum should be used. There is also mention of using some sort of molded poly compound. What are the pros and cons of Aluminum, stainless steel, poly, etc.? Any other advice/comments?
Thanks,
Jim
New Fuel Tank Material
Moderators: CaptPatrick, mike ohlstein, Bruce
a new fiberglass tank with vinylester resin is an option, but to me a very expensive one.
The problem with aluminum is after 10 years our so it can start to corrode and develop pin hole leaks. But i went with aluminum and have coated it in the Devatar, which is some bad ass stuff. For what i payed for my tank, i could have bought 2 fiberglass tanks
I dont know about stainless other than its expensive and if not welded properly can become brittle. There was some talk of it not being allowed by the coast gaurd above a certain size but I dont know.
A poly tank seems to be a good idea, and i think there are several companys that can custom make them to your specs, but as Capt. Pat as said you wont one that does not have "welded" joints.
There is also monel, but all i know about it is it is very expensive
The problem with aluminum is after 10 years our so it can start to corrode and develop pin hole leaks. But i went with aluminum and have coated it in the Devatar, which is some bad ass stuff. For what i payed for my tank, i could have bought 2 fiberglass tanks
I dont know about stainless other than its expensive and if not welded properly can become brittle. There was some talk of it not being allowed by the coast gaurd above a certain size but I dont know.
A poly tank seems to be a good idea, and i think there are several companys that can custom make them to your specs, but as Capt. Pat as said you wont one that does not have "welded" joints.
There is also monel, but all i know about it is it is very expensive
Thanks
Matt
Hull #315 - 854
Matt
Hull #315 - 854
I am going to replace my original fiberglass tank this winter due to the fact that ethanol free fuel is disappearing from our area. I currently have two aluminum saddle tanks that were installed by the previous owner nine years ago from Atlantic Coastal Welding. All their tanks come "coated " and seem reasonable and the tanks seem to be holding up well. I will obviously further inspect when I get the original tank out. Unless anybody else on this board has had any problems with their tanks. I would defenitely give them a try. They will give you a quote online quickly.
1972 Bertram 28 FBC
Stainless apparently is an option for Diesel, but not gasoline, but only if the boat is not for charter... At least that is what I think I finally figured out a few years ago when we were all having this discussion. But it is hard to find a shop to fab you any fuel tank in stainless because the regs are so confusing.
Stainless is prohibitive in cost anyway.
Most tanks are 1/8 in aluminum these days, but for not too much more you can have them fab'ed in 3/16. That little increase makes for a much more robust tank and is well worth the small expense. It isn't just the wall thickness, it is also that everywhere there is a weld it is also more robust. More material= thicker weld joint. I read somewhere a while ago that 3/16 ali tank will last much longer than a standard 1/8 thk one and I believe it having seen the two.
Peter
Stainless is prohibitive in cost anyway.
Most tanks are 1/8 in aluminum these days, but for not too much more you can have them fab'ed in 3/16. That little increase makes for a much more robust tank and is well worth the small expense. It isn't just the wall thickness, it is also that everywhere there is a weld it is also more robust. More material= thicker weld joint. I read somewhere a while ago that 3/16 ali tank will last much longer than a standard 1/8 thk one and I believe it having seen the two.
Peter
new tank material
My brother and I just had a new aluminum tank put in the boat. The guys that did it encased the tank in chopped glass (mat), sanded it and coated with several coats of interlux 2000 barrier. Hope it holds up like they said it would.
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Raybo Marine NY
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when you factor in freight most locals should be able to beat ordering one from another state
With the brackets I have put onto the tanks I have been paying about $2400 for a 240 tank, our prices are usually a little higher then other parts of the country. I bet down south you can get one closer to $2k.
Freight would have to be at least $500 and I would be really nervous as to what that tank was going through in shipping, would hate for it to be a shelf for boxes or pallets
With the brackets I have put onto the tanks I have been paying about $2400 for a 240 tank, our prices are usually a little higher then other parts of the country. I bet down south you can get one closer to $2k.
Freight would have to be at least $500 and I would be really nervous as to what that tank was going through in shipping, would hate for it to be a shelf for boxes or pallets
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Raybo Marine NY
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never mind I did not realize your boat was a 26, how large is the tank?
Is it one of those tanks that partially supported the deck?
Ask a local repair shop who they use for tanks, I always say if there are boats and marinas there are guys making tanks, they will usually advertise in one of those local fisherman or marina repair magazines/flyers
Is it one of those tanks that partially supported the deck?
Ask a local repair shop who they use for tanks, I always say if there are boats and marinas there are guys making tanks, they will usually advertise in one of those local fisherman or marina repair magazines/flyers
I replaced my fiberglass tank with a new vinylester fiberglass tank.
My main reason was a few words of wisdom from Capt Patrick. "Fiberglass has no welded seems that could possibly fail" Whether aluminum or stainless, that fact holds true. Also, I have 3 aluminum tanks that were put in by the previous owner, and all 3 failed, possibly due to improper prep or grade of the materials.
My main reason was a few words of wisdom from Capt Patrick. "Fiberglass has no welded seems that could possibly fail" Whether aluminum or stainless, that fact holds true. Also, I have 3 aluminum tanks that were put in by the previous owner, and all 3 failed, possibly due to improper prep or grade of the materials.
Harv
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scenarioL113
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The 26 tanks that I know of are shaped in cross section like a "T"
The stem part of the T goes down between the inboard stringers and the cross of the T goes outboard over them to each side.
This makes a little more trouble when replacing the tank because unlike a rectangular tank that simply sits on a piece of deck, or a V bottomed tank that sits on the hull, the outboard wings of the T in our boats must either be robust enough to support themselves or they must be supported in some other way.
It sounds simple enough to make supports for three places on the new tank; under the bottom of the stem part and then at the ends of the two wings... but to actually do so with precision is not so simple. Especailly if there are globs of fiberglass and resin from the original layup that are not precise.
Furthermore in the 26 era nothing about the layup was dimensionally precise. Bertram seemed to be moving in a direction to reduce production costs as they built these boats. Hence the design changes from the 25 two-piece mold with tumble home and a bumped out transom to the 26 one-piece mold and its modular construction. Hull, deck/liner, weather deck, and house were each laid up seperately and then married together on the production line. Later 26's in the USA didn't have the option of the house, though this variant is still in production in Aus. today.
I found in my 26 that although the glass work was very strong and of good quality, the hull stringers were not perfectly parallel, the deck/liner wasn't symetrically bonded to the hull, deck beams were no where near parallel, and multiple other minor dimensional quirks.... including large globs of glass and resin in some places as fillets that were not precisely matched elswhere. That sort of stuff.
In that era not much thought was given to things like low VOC production techniques, or vacuum bagging to control glass/resin ratios, or production jigs to assure precise alignment of various parts. A gang of guys got in there and glassed the assembly together so that it was close enough to look good, work well and take a beating. And it does do all of that. But it isn't dimensionally precise anywhere.
When you go to put your new tanks in that can bite your ass really hard if you haven't done a good mock up. DO NOT fab a tank without mocking it up first! And from personal expereince I recommend going with thicker material for the tank so it is more self supporting at the wings.
The 26's had tanks that were close to the underside of the decks in places. In my boat the deck (lazerette hatch actually) had a soft spot so the previous owner had stuck a shim there to support the deck on the tank top. It wasn't meant ot be like that. As far as I know no 26's had decks supportedby their tanks, and you should be suspicious if you find evidence of anything like that. BUT due to the large removeable deck hatchs over the tanks in the 26's sooner or later you or some boat yard monkey will step on the top of the exposed tank.... making it a-deck-in-fact in its own right. Another reason to go with the thicker material.
Lastly I spent days pouring over various production poly tanks. Save yourself the time. In the end there was no tank that fit the "T" cross section needs. I found using production tanks I was stuck staying inside the inner stringers and that limited my capacity too much. So a custom fab in metal was the way to go. I pressed for stainless even though regs are sketchy, but when I fnally go a price quote I settled for 3/16 aluminum.
The 3/16 aluminum tanks are serious business... not in the least bit flimsy. I can walk all over the tops of them wihtout any sense of a problem, and the wings of the T are plenty strong. And the cost adder was minimal in the scope of the project.
One final caution: I sent out drawings for quotations to several companies... about half returned a quotation for 1/8 inch material even though I clearly stated in the RFQ and the drawings I wanted 3/16. Be sure to specify EVERYTHING. Every dimension and vent and pick up and fill and electrical bonding connection. All of it. And then cross check your quotes to be sure you are getting what you asked for. The lowest, quickest price may not be what you think you asked for at all.
Peter
The stem part of the T goes down between the inboard stringers and the cross of the T goes outboard over them to each side.
This makes a little more trouble when replacing the tank because unlike a rectangular tank that simply sits on a piece of deck, or a V bottomed tank that sits on the hull, the outboard wings of the T in our boats must either be robust enough to support themselves or they must be supported in some other way.
It sounds simple enough to make supports for three places on the new tank; under the bottom of the stem part and then at the ends of the two wings... but to actually do so with precision is not so simple. Especailly if there are globs of fiberglass and resin from the original layup that are not precise.
Furthermore in the 26 era nothing about the layup was dimensionally precise. Bertram seemed to be moving in a direction to reduce production costs as they built these boats. Hence the design changes from the 25 two-piece mold with tumble home and a bumped out transom to the 26 one-piece mold and its modular construction. Hull, deck/liner, weather deck, and house were each laid up seperately and then married together on the production line. Later 26's in the USA didn't have the option of the house, though this variant is still in production in Aus. today.
I found in my 26 that although the glass work was very strong and of good quality, the hull stringers were not perfectly parallel, the deck/liner wasn't symetrically bonded to the hull, deck beams were no where near parallel, and multiple other minor dimensional quirks.... including large globs of glass and resin in some places as fillets that were not precisely matched elswhere. That sort of stuff.
In that era not much thought was given to things like low VOC production techniques, or vacuum bagging to control glass/resin ratios, or production jigs to assure precise alignment of various parts. A gang of guys got in there and glassed the assembly together so that it was close enough to look good, work well and take a beating. And it does do all of that. But it isn't dimensionally precise anywhere.
When you go to put your new tanks in that can bite your ass really hard if you haven't done a good mock up. DO NOT fab a tank without mocking it up first! And from personal expereince I recommend going with thicker material for the tank so it is more self supporting at the wings.
The 26's had tanks that were close to the underside of the decks in places. In my boat the deck (lazerette hatch actually) had a soft spot so the previous owner had stuck a shim there to support the deck on the tank top. It wasn't meant ot be like that. As far as I know no 26's had decks supportedby their tanks, and you should be suspicious if you find evidence of anything like that. BUT due to the large removeable deck hatchs over the tanks in the 26's sooner or later you or some boat yard monkey will step on the top of the exposed tank.... making it a-deck-in-fact in its own right. Another reason to go with the thicker material.
Lastly I spent days pouring over various production poly tanks. Save yourself the time. In the end there was no tank that fit the "T" cross section needs. I found using production tanks I was stuck staying inside the inner stringers and that limited my capacity too much. So a custom fab in metal was the way to go. I pressed for stainless even though regs are sketchy, but when I fnally go a price quote I settled for 3/16 aluminum.
The 3/16 aluminum tanks are serious business... not in the least bit flimsy. I can walk all over the tops of them wihtout any sense of a problem, and the wings of the T are plenty strong. And the cost adder was minimal in the scope of the project.
One final caution: I sent out drawings for quotations to several companies... about half returned a quotation for 1/8 inch material even though I clearly stated in the RFQ and the drawings I wanted 3/16. Be sure to specify EVERYTHING. Every dimension and vent and pick up and fill and electrical bonding connection. All of it. And then cross check your quotes to be sure you are getting what you asked for. The lowest, quickest price may not be what you think you asked for at all.
Peter
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Raybo Marine NY
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the tank should not support the deck in any way. Peter gives great advice and if your boat is not true error on the side of caution and make the tank a inch or two smaller to allow for clearances
Ideally your existing tank can be removed in one piece and brought to a local shop where you can explain it in person and the shop can even come to the boat and see what is going on. This is a huge benefit of dealing locally. Much easier to magic marker your tank with instructions then dealing with faxes and emails.
Ideally your existing tank can be removed in one piece and brought to a local shop where you can explain it in person and the shop can even come to the boat and see what is going on. This is a huge benefit of dealing locally. Much easier to magic marker your tank with instructions then dealing with faxes and emails.
Cunado,
I went through Tempest Marine. They use a welder in Freeport -can't remember his name that supposedly does very good work. It did take a while though due to his schedule but it afforded us the time to get some other things done while out of the water. They then glass the tank, sand and barrier coat it. Used 3/16 aluminum. The tank looks good.
I went through Tempest Marine. They use a welder in Freeport -can't remember his name that supposedly does very good work. It did take a while though due to his schedule but it afforded us the time to get some other things done while out of the water. They then glass the tank, sand and barrier coat it. Used 3/16 aluminum. The tank looks good.
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scenarioL113
- Senior Member
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- Location: Massapequa Park, NY
i had a welder here that could have done it, but he mostly does smaller tanks, is not "certified" and because i wanted 1/4" he really didnt have a large enough welder and the only other "certified" welder wants around $15 a gallon and only wanted to use 1/8" o 3/16" wouldn't do 1/4". And everyone else local wants about the same. i paid less than $10 shipped
it just wasnt worth the hassle or cost to do it local. I know that sounds stupid, but i sent the guy in florida a drawing and in about 3 weeks it should up on a pallet at the office.
AND i agree with Peter that the low bid will normally end up costing you more, but in this case, i checked and checked and it was what i wanted to a T
J right now is in tiki where we are working on it. It was at GYB
it just wasnt worth the hassle or cost to do it local. I know that sounds stupid, but i sent the guy in florida a drawing and in about 3 weeks it should up on a pallet at the office.
AND i agree with Peter that the low bid will normally end up costing you more, but in this case, i checked and checked and it was what i wanted to a T
J right now is in tiki where we are working on it. It was at GYB
Thanks
Matt
Hull #315 - 854
Matt
Hull #315 - 854
Raybo Marine and Peter,
I am defenitely going to follow your advice and do a mock up before ordering a tank. I currently have very little clearance between the original and saddle tanks.
Coolair and JDavis,
Thanks for the info!
I have ran into the same situation as coolair. I even called the most reputable shop in my area and the boat yard I use and they order their aluminum tanks from Florida "because they are done right" and they also suggested I consult this website. Although Texas has a vast coastline, besides the Galveston area, areas with a handful of marinas and neighborhoods with canals are miles a part which might be why we have a hard time finding someone that advertises that they fabricate marine fuel tanks reasonably and often. I am amazed anytime I have been on the East Coast how many beautiful boats, marinas , yacht basins , canals etc. which obviously leads to more local options for the owners there.
Brad
I am defenitely going to follow your advice and do a mock up before ordering a tank. I currently have very little clearance between the original and saddle tanks.
Coolair and JDavis,
Thanks for the info!
I have ran into the same situation as coolair. I even called the most reputable shop in my area and the boat yard I use and they order their aluminum tanks from Florida "because they are done right" and they also suggested I consult this website. Although Texas has a vast coastline, besides the Galveston area, areas with a handful of marinas and neighborhoods with canals are miles a part which might be why we have a hard time finding someone that advertises that they fabricate marine fuel tanks reasonably and often. I am amazed anytime I have been on the East Coast how many beautiful boats, marinas , yacht basins , canals etc. which obviously leads to more local options for the owners there.
Brad
1972 Bertram 28 FBC
If I can add my opinion, I recently made my tank out of 3/16 aluminum.
Stainless they say can crack.
I found that many people had breaks that could not bend over 1/8" stock.
Putting fiberglass over an aluminum tank may seperate, trap water inbetween and cause the tank to fail [I hope [I'm wrong].
Stainless they say can crack.
I found that many people had breaks that could not bend over 1/8" stock.
Putting fiberglass over an aluminum tank may seperate, trap water inbetween and cause the tank to fail [I hope [I'm wrong].
what good is a boat if you cant spend all your money and time you dont have working on it.
Here are some picture of the tank in my 26 with the top cut off and the baffles cut out. And a picture of the deteriorating insides.
http://i828.photobucket.com/albums/zz20 ... 0_2494.jpg
http://i828.photobucket.com/albums/zz20 ... 0_2500.jpg
http://i828.photobucket.com/albums/zz20 ... 0_2494.jpg
http://i828.photobucket.com/albums/zz20 ... 0_2500.jpg
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In Memory Walter K
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fuel tanks
if u aregoing to charter or insure the boat which may invite a marine surveyor aboard, they probabably will want to know if the tank meets any certication requirements so they have someone else to passoff the liability, keep a copy of the cert since the decal may become tough to view, been there
A number of the posts above and other posts on the forum about replacing fuel tanks speak of removing the tank. We are planning on keeping the existing tank in place after the top is cut off and the baffles removed. (See the photos above). We are having the new tank made to fit inside the old one and filling the gap with foam. Is there a problem with that scenario?
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CaptPatrick
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