Sealing rust pin holes in gas tank

[Limey57]

Today I started to strip and clean the outside of the gas tank so I can paint & re-fit it.  The part that sits against the underside of the trunk floor had plenty of rust pits, one of which turned into a small hole when cleaning.....  In an ideal world I'd order a new one but the time and cost to ship a new tank from the US to England is prohibitive (for some reason postage costs from the US have gone through the roof).

The pictures below show the tank, the pitting and the hole.  Trying to weld it will probably end up in the pin hole turning into a huge hole.  Is there anything on the market (possibly by POR?) that can be painted on and is thick enough to fill in small holes?  The tank has already had some soldered and brazed repairs in the past.

[lalessi1]

Gary, I would try JB Weld epoxy putty. I have not used the one for steel but I used the one for plastic. You knead the stuff to mix the hardner in and it has the texture of clay. I fixed a crack in my pool filter merely putting it the outside of the crack and it holds against 15 psi!!!! They say this stuff will set in gasoline. you can also sand it and finish it.

http://www.eastwood.com/jb-weld-stick-8267.html?fee=7&fep=49569&adpos=1o5&creative=61491480420&device=c&matchtype=&network=g&gclid=CjwKEAjw8LOsBRDdub-swPW8riISJAAnmS01bek1LV3v3hBFHwLDrqsu44vT3KtEh5eCRiSrWZ1z2BoCZU_w_wcB

[Limey57]

Excellent, forgot about JB Weld, Eastwood have a UK distributor so I'll give it a try, thanks.  I'll use the POR metal prep first to get rid of as much rust as possible first.

[petew]

I spoke with someone at JB Weld specifically about using their product to seal a gas tank. They said that once completely cured JB Weld is impervious to gasoline . They suggested the regular two part product which I have used to seal VW gas tanks where they rust at the very bottom. It worked like a champ.

[Limey57]

That's great to hear, thanks.  Getting nearer and nearer to completion, the gas tank is just about the last bit that needs painting now!

[BBoswell]

I recently had to have a hole in my gas tank repaired. The hole which was causes by a rubbing exhaust pipe was definitely larger than a pin hole. I took it to the local radiator shop and they soldered on a patch panel. Worked out great. I would think doing a pin hole would be a snap. They could probably flow the solder on and cover more than just that small area. Just another idea since you already have the tank out.

[John Palmer]

If soldering the hole, don't use a torch to heat the area for the repair unless the tank has first been boiled out to remove all the gas fumes.

I have seen "old timers" fix gas tanks with "an old style heavy copper soldering iron".  They would use a gas torch to heat the iron, use acid and solder to tin the surface, reheat the iron, then solder the hole.  By doing it this way, you do not have an open flame near the tank, and no sparks to ignite the tank.  I saw a guy fix a hole in a "in cab" gas tank on a early Ford truck with this method.

[RICH MUISE]

Whichever of the three methods you use (the por 15 or por patch would work as well), finish up the outside of the tank with por-15

[Thor]

JB Weld will work for sure. Back around 1980 the fellow I worked for at the time had an old 8000 gallon semi tank trailer that had a rust thru spot that was leaking near where it hooked up to the truck. It had multiple pin holes that were leaking. We wire brushed the area, mixed up two packages of JB Weld, smeared both sides of a clean red shop rag and the area of the tank that had been leaking, and then stuck the JB Weld / rag over the area and let it set up. The last time I spoke to this guy in 2001 he joked with me about the repair telling me "the tank was still holding and would probably outlast the tank".   

[jwag]

I have used the regular JB weld in the past and found that it lasted about a year before it started leaking again. The steel stick might work better and would be worth a try. I am in California and have been told that the ethanol blend we have in out gasoline makes it more difficult to get a permanent seal.

[BBoswell]

I hadn't thought about that but the ethanol blend could be an issue if you live in a state where they have it. Definitely food for thought. I live in Oregon and the ethanol blend gasoline creates all kind of carb and fuel issue . . . especially if you don't drive your car much . . . plus the gas evaporates a lot faster. I can tell you that the soldered repair on my gas tank is holding well and shows no sign of breakdown.

[Ecode70D]

Solder it or have it soldered.   Then coat it all over with POR 15.   If you can't get POR 15.  Use something like Rustoleum.

[Mark]

I soldered a pin hole in a gas tank about 4 years back, but another hole started dripping and I got a new tank. If there's one there's going to be more.

[Zapato]

Sherwinn-Williams in their industrial line has a gas tank sealer. I've used it in a couple cars. Stuff was developed for the US Navy onboard plumbing. Its kind of like Pepto-Bismal for gas tanks. Pour it in and slush it around everywhere. Pour out excess. Cures in 24 hours or so. Good to use after boiling out the gas tank. It will seal pinholes.

Regular S-W paint stores wont know anything about it. You need to go to one of their industrial dealers.

Zap-