fuel tank

[captphil416]

Deep Blue currently has an 11 gal. plastic diesel tank. A custom tank to fill the space could hold about 15 gal. An aluminum one is prohibitevly expensive. Is it possible to make one using stitch and glue techniques, with epoxy, and multiple layers of glass cloth? Has anyone ever done this, or heard of such a thing? Thanks Phil

[barrybrown]

Phil,
I just replaced the fuel tank on my ec triton this spring, admittedly 'prohibitively expensive' is subjective but I was surprised by how reasonable it was
it was made from 1/8" 5200 aluminum with one cleanout, just slightly smaller than the original - 17 gal. instead of 18. price $509.
It was made by RK Welding in Pocasset, MA.
I'm not saying it was cheap just less than I expected.

Barry

[ILikeRust]

I would consult both USCG regulatory requirements as well as ABYC standards.

I would be seriously hesitant to try going about fabbing up my own fuel tank. It's one thing if your fresh water or even grey or black water holding tank leaks or ruptures inside your boat; it's quite another when a tank holding 15 gallons of flammable liquid leaks or ruptures.

The marine environment is notoriously harsh and unfriendly. Don't forget the forces the tank will be subject to - it's not just the weight of the fuel sitting in the tank, but also the movement of the boat, rocking and rolling on waves, getting bounced around, vibrations from the engine, etc., etc...

Considering that you're talking about not only the investment in your boat, but your potential passengers, I would not think that $500 - $800 for a new gas tank is "prohibitively" expensive. I would consider it money wisely and well spent to make sure I had assured the best, most reliable and safest setup I could.

There are just certain elements of the boat I won't try to fab something up myself. The fuel delivery system definitely is one of them.

Also consider the potential later resale value of the boat. Will someone be more impressed by a professionally manufactured Monel fuel tank, or by a plywood and epoxy stitch and glue tank that the boat's owner fabbed up?

[mitiempo]

It can be done and ABYC allows fiberglass fuel tanks. But I wouldn't do it.

I will be building a holding tank with epoxy and glass over plywood.

[captphil416]

Thanks for the input.. The set up I have works fine, and perhaps not all ideas are good ones. Phil

[bcooke]

My custom aluminum 27 gallon tank was around $500 to fabricate. It had a lot of funky angles and wasn't simple to make.

If that is too expensive Figment had an off-the-shelf 10 gallon tank that I believe was a lot cheaper. There is a thread around here somewhere on the topic.

[Zach]

Do not build a fiberglass fuel tank, for diesel or gasoline.

Neither last, with ethanol as an additive. All sorts of boats are having problems with their fiberglass fuel tanks, epoxy and polyester. Not just boats, but old custom motorcycles and hotrods of varying sort with coated fuel tanks.

There is basically no coating that you can apply to keep the resin matrix from deteriorating in the presence of ethanol. There are resins that are better with ethanol, but most are not.

http://www.boatus.com/news/ediesel_0707.htm

I had good luck with RDS on a project. http://www.rdsaluminum.com/

They can build them coast guard approved. The only pain with aluminum tanks, is that the rest of the system has to be aluminum hardware or stainless steel. It is hard to find some fittings and adapters in aluminum or stainless, so find the hardware you need before you spec the fitting sizes.

[Figment]

Having gone both routes in the past, I say with absolute certainty: Such a minor increase (roughly 30%) in capacity is NOT worth the effort of a custom tank.
Britton's Big Red Monster was a significant increase.

[triton318]

Does anyone know if there's ethanol in kerosene? I'm considering building a 5 to 8 gallon tank for kerosene out of plywood and epoxy. I've already built two potable water tanks using this construction with excellent results. (Resale value is of no concern for me -- that's one positive of being older and having a boat that will serve my needs until I die!)

[mitiempo]

I don't believe there is any ethanol in kerosene.