GW Fuel tanks

[ScottyCee]

I can't remember whether my fuel tanks are stainless or aluminum. 1998 Sailfish. I can pull a hatch next time I'm on the boat, but does anyone know off the top of their head?

Thank you.

 

[seasick]

I don't think I've ever seen a stainless tank.I have seen monel , poly, aluminum and steel but not stainless.

 

[wspitler]

Aluminum!

 

[blindmullet]

I don't think I've ever seen a stainless tank.I have seen monel , poly, aluminum and steel but not stainless.

Yea, stainless would be pretty pricey for a production boat, but they are available. Add fiberglass to the list. More common on diesels.

 

[seasick]

I would think that stainless would be prone to rusting in a recreational hull. For the record, I have only seem monel on diesels and I didn't know that it was monel. Unlike aluminum, monel will attract a magnet but looks and 'scrapes' like aluminum.

 

[Uncle Joe]

I have replaced 3 or 4 and they were all aluminum.

 

[DennisG01]

From the factory, it would be aluminum. But unless you bought the boat new, there's no way to be sure as it could be stainless or something else.

 

[ScottyCee]

Great. Thanks guys. Yeah aluminum. I was hoping for stainless cuz I find it much easier to weld.

 

[seasick]

Not properly welding or soldering a gas tank can be a fatal mistake. If you do not have experience, don't try iy on a tank that has had gas in it. Vapors stay almost forever and that is a recipe for a bomb. I have seen it.
Gas tanks may be filled with water to weld or filled with inert gas like nitrogen. I have heard about but not seen dry ice being used too. Supposedly that freezes any has liquid and also fills the tank with carbon dioxide gas vapors

 

[ScottyCee]

Thanks. I promise not to blow myself up.

By the time they get welded they would be spotless inside. My early though is to cut a fair sized hole in the tops to facilitate scrubbing / cleaning, but I still kind of suck at TIG and that might require a back purge for which I'm not yet set up. If they were stainless (I thought they were), then it would be a quick job using 308 or 316 wire - whichever worked better in test. Oh well. I'll have to figure out plan B.

Other than paying someone else to do it (I won't do that) what options for cleaning 22 year old fuel tanks are there?

 

[wspitler]

Most of these tanks are 0.125" thickness 5000 series aluminum. If your problem is corrosion and not simply cracks it may be difficult to repair/weld. Since water is normally on the bottom, most tanks corrode there as well as on top. I'm sure you know you can't weld oxidized aluminum and it is very easy to oxidize it during the welding process. Patching spots is an option, but even those who do it every day and are very, very skilled will be challenged.

 

[PointedRose]

My 2 cents - get a new tank and don’t worry for another 20 years

 

[ScottyCee]

My problem is that they were full of crud, and even though I vacuumed them out pretty well last year I am not confident that they are completely clean - I am cleaning my VST filters too often. I have not seen the bottoms, but the tops were extremely dirty when I pulled the hatches last year.

How much do you think a pair of 56 reserve and 150 main (think those numbers are right - it's a 98 272) tanks would set me back?

 

[Uncle Joe]

A few years back my 93 gal main for my Offshore cost me $1100 to have fabricated. Hope that helps.

 

[wspitler]

Check with Florida marine tanks, used to be in Florida, now in North Carolina. They still make Grady tanks I believe.

 

[Ky Grady]

Bought both my main and auxiliary tanks from FMT. Nice facility in NC,, got to tour it.

 

[ScottyCee]

Yeah, sounds like maybe ball park of $2+K + cross country shipping. Probably not happening. If I have to "get small" and go inside them myself that's what I'll do.

Actually I could fabricate them myself for a fraction of that, and by the time I finished I would be far better at welding aluminum. I would probably also change to just a single tank of maybe 125 gal. I never run with 200+ on board. Too heavy and no reason to where I am.

Thanks for the info guys!

 

[PointedRose]

Poly might be cheaper than alum cost for new. Also be just as careful if you cut into the tanks - that could be a bomb too