Gas Tank Bedding And Repair

[AJSVFORCE]

I have a 50 gallon under deck fuel tank that was bedded in the flotation foam. I am replacing the deck and stringers and need a new bed for the fuel tank,any ideas?
Next question,the tank is made of aluminum and was covered in white corosion,i took a wire brush to it and have found many fairly deep pits,i dont want to seal this thing up under a new deck only to have it leak and i cannot afford to buy a new one.
Has anyone run into this and what did you do to fix it?
Thanks,
Andy

 

[drewpster]

Re: Gas Tank Bedding And Repair

The pits are not a big deal unless they are very deep and compromise the integrity of the tank. I would remove the tank and pressure test it for possible failures prior to re-installing it. An easy way to check it would be to simply fill it with water out of the boat and look for wet spots. Siphon the water off and dry the inside of the tank after the test.
A preferred way of doing it would be to empty the tank completely. Make provisions for draining it dry and pressure test it with water, air, or both.

 

[AJSVFORCE]

Re: Gas Tank Bedding And Repair

Some are deep enough that im not putting it back in without some type of repair, i have found aluminum repair solder that you can use with propane turbo torch. Just wanting a few options.
Also was thinking about coating with POR 15 paint.

 

[drewpster]

Re: Gas Tank Bedding And Repair

Keep in mind that the tank will operate under very little pressure. If the walls of the tank are heavily pitted and the structure of the tank as questionable, I would not use it. Just how bad is it? Have any pictures?
I doubt pitting, unless it is very pervasive, is going to be a big problem. Do you boat in rough water?

 

[Bob_VT]

Re: Gas Tank Bedding And Repair

I have a 50 gallon under deck fuel tank that was bedded in the flotation foam. I am replacing the deck and stringers and need a new bed for the fuel tank,any ideas?
Next question,the tank is made of aluminum and was covered in white corosion,i took a wire brush to it and have found many fairly deep pits,i dont want to seal this thing up under a new deck only to have it leak and i cannot afford to buy a new one.
Has anyone run into this and what did you do to fix it?
Thanks,
Andy

Lightly sand it, wipe it with vinegar (let it dry) and paint a coat of gluvit over the surface. You can only do i side at a time since the gluvit will creep and flow. Leave the surface horizontal until it has set.

When you are done and ready to bed the tank use a sheet of paper between the tank and the foam to prevent the foam from bonding. When the foam has set lift out the tank and make sure there is a place for moisture to drain away from the tank. The tank will sweat when filled with cold gas and there needs to be a place for the moisture to go. Just push in a path in the foam or cut a path.

 

[AJSVFORCE]

Re: Gas Tank Bedding And Repair

Thanks for the help,what is Gluvit and how much does it cost and where can i get it?

 

[Bob_VT]

Re: Gas Tank Bedding And Repair

Gluvit is an epoxy made by marine tex. The cheapest place to get it happens to be iboats. http://www.iboats.com/Boat_Parts_Ac...314414--keywords.gluvit--**********.671760328

It works on wood or metal but really is designed to stop leaks in aluminum hulls. You need the smallest can they sell.

Use the search function and you will see we use it on just about every aluminum boat at the seams, rivets and thin places.

 

[AJSVFORCE]

Re: Gas Tank Bedding And Repair

Is the gluvit Gas and Solvent proof?

 

[TheWoodCrafter]

Re: Gas Tank Bedding And Repair

I would think it is since it is an epoxy type product.

 

[jonesg]

Re: Gas Tank Bedding And Repair

Thats called crevice corrosion, the tank was improperly installed with the foam. Nothing should touch alum or allow water to pool without air circulation all around.
This is how I ended up doing mine.
I used PL adhesive from home depot, cost $5.
http://www.yachtsurvey.com/fueltank.htm

Now is the time to replumb too.
BTW, I got an almost new 50 gal alum tank off craigslist for $100, I see them all the time. I wouldn't put a corroded tank in a boat....or bother trying to fix, theres 2 stainless tanks on the Boston craigslist from a chris craft $100 ea.


and don't put a torch near an empty fuel tank unless you fill it with water first. kaboom.!

 

[jonesg]

Re: Gas Tank Bedding And Repair

http://boston.craigslist.org/sob/boa/1235240053.html

 

[109jb]

Re: Gas Tank Bedding And Repair

I would think it is since it is an epoxy type product.

I would check. Epoxy is fine with gas as long as it doesn't have any ethanol in it, but near me you won't find gas without ethanol except at an airport. The alcohol can soften epoxy depending on the formulation. Airplane builders have experienced softening of epoxy constructed fuel tanks when using auto fuel and the practice these days is to cover the epoxy tank construction with a special epoxy that is specifically formulated for sealing fuel tanks. One such product is Jeffco 9700. This link is what I'm talking about. It isn't cheap though.

 

[jonesg]

Re: Gas Tank Bedding And Repair

tanks are cheap. The rest is simple to figga out.