[oldred]

I need to seal a fuel pump/sender unit to a gas tank and I cannot find the rubber gasket material I would like to use. I can find the common cork/rubber gasket in the right thickness but I am not so sure about using cork to seal gasoline especially for a critical seal like this because it could create a dangerous situation if it leaks. I really don't think silicone sealer would work here because the gasket needs to be about 1/16" thick because of a lip on the pump unit where it seals to the tank and since the unit and tank was modified a factory gasket will no longer fit. Any suggestions on what I might use and what do you guys think about using the cork, am I being concerned over nothing?

Thanks

[Notorious]

What kind of vehicle are you working on? Or is this a special application? Actually the good quality cork/rubber compositions should work fine. I've seen plenty of carb bowl gaskets for example, made of that material over the years.

[Henry Highrise]

I use a product called Seal-All.....it is gasoline resistant. It comes in a tube and I get it at Wal-Mart.

[oldred]

This on a Kia Sportage and the top of the gas tank had rusted out so when the pump unit was removed it just ripped holes in the tank instead of the screws (yep, sheet metal screws not bolts) coming out and the top of the unit was corroded so badly it needed replacing. The tank and pump unit together cost about $1000.00 to replace so I just machined out a ring with bolt holes threaded in it and welded it to the tank then made a matching piece that was then welded to the unit. This is a much heavier and larger piece but there is no factory gasket so I will make one to fit but when I made this thing I was planing to use the 1/6" rubber that I can't find.

Notorious- now that you mention it I have seen those carb gaskets made from cork but I was thinking that most of the time a gasket for gasoline is made of rubber (or at least a rubber like) material, not sure where I got that idea.

Henry, Is that a silicone type of material in a tube? I am kind of leery of using silicone in a place that requires a gasket that thick but something like Permatex only thicker might work. If I had of known the rubber gasket material was so hard to find I would have grooved this thing for an O-ring but it is already welded in now so that idea is too late.

[Henry Highrise]

No it is not silicone. I use the Seal All on both sides of a cork gasket. As a matter of fact a lot of fuel sending units come with cork gaskets and are put on without any sealant.

[oldred]

Ok it sounds like I am concerned over nothing and the cork will be the thing to use, I will check out that sealer when I pick up the gasket material.

[jimfulco]

Go to a real auto parts store and get a sheet of gasket material that will hold up to gas. Cut it to whatever shape you need.

No such luck? A piece of heavy cardboard cut to shape and slathered with liquid Permatex (either Aviation or Super 300) might work. Let it soak in for a while, then coat it again. Gas won't eat the Permatex, but you can clean up the mess with alcohol.