Composite Gasoline Tanks

[wet feet]

If I was in the position of having to produce my own composite tank to fit a hull,it would be made in two halves.Or more accurately a large bottom section with a flat top panel.It would be a last resort and I would much rather use a metal tank,even if it meant attaching insulating pads of rubber or plastic to the hull to minimise the risk of galvanic corrosion.Given no alternative,I would use a male mould for the majority of the tank and avoid all through fittings in that section.I would have an outward facing flange that could be used for bonding the lid in place and I would be very generous with the bonding paste.I might also try to apply some suitable composite joining strip over the flange once bonded.The op panel would have the filler neck attached before it goes on the assembly and there would be a pick up tube from the top to a point an inch or so above the lowest corner of the tank.

Again,I would go to some lengths to avoid a composite tank and am a bit surprised that a fellow who can afford to run a 175Hp motor is baulking at the cost of a much safer metal tank.

 

[gonzo]

oy). The possible source of fire is the bilge system. Nothing else sparky under there.

A bilge pump and its auto switch can fail and spark.

Vent: If you mean the underfloor space, no. It's a 6m trailer boat. I don't think anyone has ventilation in those spaces (passive or active).

That would be a bilge blower, which is standard in most places.

 

[sdowney717]

Steel tanks rust on the inside. Ethanol gas is the reason why, no condensation if tanks are full, but the ethanol still corrodes the steel tanks as it naturally has dissolved water in the fuel. A dangerous and big problem in a few years of use with steel and gasoline. Just avoid the problem by not using steel tanks with gasoline. I would feel very nervous and worried about a large steel tank full of gasoline in a boat, would feel like riding around with a fuel air bomb.

My old Egg Harbor has twin saddle tanks made of Monel metal with machine welded seams, and I still worry as they are old. Each one is 145 gallons.

Currently working on the bottom and was thinking what if I drilled a hole in the boat bottom and punctured the tank!

But I was looking closely and they are far away from inner hull, that would be unlikely.

I have a chine plank off and can see the spacing from plank to framing to tank.

Tanks have round edges, no corners. Are 18" tall , 12 " wide and very long, like 8 feet or so. Made of Monel sheet metal in 1970