Making a fuel tank with G10 fiberglass board

[lizardheadone]

Has anyone fabricated a diesel fuel tank from G10 fiberglass/epoxy board? I was just wondering if you could build a succesful fuel tank by fiberglass taping G10 board together. What ya think?

[mitiempo]

It could be done, but g10 isn't exactly inexpensive. Have you priced it out yet? How big a tank? You probably wouldn't save much over having one professionally made in stainless and it's a bit of work. If you want to build one use plywood and epoxy it well inside and out - a lot less expensive. Here's a link to a pdf from West epoxy detailing how to go about it.
http://www.epoxyworks.com/18/pdf/tanks.pdf
Brian

[jrd22]

Or just make up a mold and make a glass box with no top, then make a flat board and glass it on to make the top. Making fiberglas boards is easy and fast, as long as you're not too fussy about how they look

[mitiempo]

jrd22
Why go to the trouble of making a mold and using a lot of glass and epoxy? If you build it of thin plywood you'll use a lot less epoxy and cloth for the same result.

[tommays]

Fuel tanks have a certification tag and it will be a sticky insurance area if you DIY one as there is a LOT of Conforms U.S. Coast Guard regulations

[mitiempo]

tommays
Tanks purchased from a tank manufacturer do but custom tanks do not have certification tags. It is a long and expensive process to certify a tank. If they all had to be certified there would be no custom tanks.

[tommays]

Yes

But the builder is certified at least in the US

Just like pressure vessels like air tanks have to 100% certified

[mitiempo]

Here is a link to a pdf explaining how to build a fuel tank from fibreglass. http://www.practical-sailor.com/news...glasstanks.pdf
In Canada I know of no regulation either preventing you from building a fuel tank or requirements for the builder of a custom tank to either have it certified or in fact be certified himself. I have owned 3 boats over the years that I have had custom tanks made for and the issue has never come up. All tanks were stainless steel and pressure tested to 5 psi. I've never been asked by an insurance company for any fuel tank certification. I do prefer stainless steel to other materials. I tried to find Canadian pleasure craft fuel tank regulations on the web but all I found was a Canadian Government site that referenced ABYC.

[jrd22]

Mitiemp- it would be easier to use plywood and as long as it was saturated with epoxy I don't see why it wouldn't work, but all glass would eliminate any worry about the wood becoming saturated with diesel at some point or the plywood dry rotting. Our tanks are also SS and so far so good, but all metal tanks will probably leak or fail at some point. Integral fiberglas tanks would seem to be the all round best route but difficult to retrofit.

[mitiempo]

jrd
I replaced a 32 year old steel tank this past winter. In my boat the tank (about 14 gallons) was hung below the cockpit with nylon straps. The original tank was rusted on top (but not leaking) because the fuel fill was in the cockpit sole and water leaked around the fill fitting onto the tank top. I think that is the wrong place for a fuel fill so it is now on the side deck on a slightly raised base. The new stainless tank is not held in place with straps but has two vertical strips welded on top for its length and is bolted to two structural beams underneath the cockpit sole. The underside of the tank is clear so the tank is not able to sit in water as a tank often is. I expect to get at least 32 years use out of this tank and as I'm 57 now that should be long enough.
As far as a glass tank I came across an article about building fibreglass tanks http://www.practical-sailor.com/news...glasstanks.pdf
that detailed a case of a balsa cored fibreglass tank that was in a fire. The details are below. I would think that a plywood core would act the same way and be durable and leakproof as long as the outer and inner skins were thick enough. The tank in question had 1/8" thick skins which seems a bit light to me.