non-valk plastic gas tank question

[Big IV]

When a car gas tank gets a pin hole (rust or hit by debris) I have went to the automotive store and picked up a 2 part compound that you rub together and then slap on. Binds to the metal. Works really well.

I just purchased a truck that has a leaking gas tank. Former owner slapped several patches on it and then decided to sell. I figured I could always stick a new tank under it and sell it. When I was looking it over I realized it has a plastic tank.

I wasn't sure if the gas tank sealer for metal would work on a plastic tank or not, although that is what he used.  I tapped it gently with a screwdriver and it fell off in a chunk, which answers that question: not attached at all really.

I have found one small hole, but low enough on the tank to be annoying and empty the tank out as it sits.

Anyway, long story long, here is my question:
Is there a plastic epxoy that can be used on gas tanks?  Any recommendations?

[Shockbushing Gary]

The PVC compounds are hard to get adhesives to bond to. They cure with an oil in them that makes most adhesives lose grip. The common method of repair (when it's not a fuel tank) is plastic welding. Don't know that I'd try that with a fuel tank, but with some inert gas filling it, you might. Don't say I told ya to, tho!
We've had some success on test equipment by buying a bulkhead fitting and clamping it over the hole. You would need to be able to access the inside of the repair point with your hand, tho. Most late model plastic tanks have a big hole in the top. Maybe that would work.
Last, if the cost of a wrecking yard tank isn't too much, maybe that's a valid repair, and less hassle that putzing with a half measure.

[Big IV]

can't do a bulkhead fitting because it isn't an uniform shape.
Plastic welding? Nah, if it comes to all that I'll go to the junk yard.
Buying one used is probably plan B at this point. I'm trying to do this as cheaply but well as possible since I don't plan on keeping the Dakota, but instead re-selling it.  But I don't want to do it half-ass either (otherwise I'd be chewing some gum!)
They have to make something for plastic tanks. Perhaps I'll stop bythe auto store on the way out to dinner tonight.
Any other suggestions please let me know.

[junior]

got an old bedliner? and a soldering gun ? cut a splinter of bedlinger and use the soldering gun to melt it over the pinhole it works well and i have good luck with it not leaking afterwards.

[Madmike]

If it's just a pin hole you may want to try using a hex head metal roofing screw with a rubber washer.

[Daniel Meyer]

If it's just a pin hole you may want to try using a hex head metal roofing screw with a rubber washer.

I've done that. Slapped some gasket maker (good for gas-type) on the threads before I screwed it in.

Worked for the life of the truck.

[Bill Laslett]

If the hole is to big for a screw you could use a toggle bolt with a fender washer and rubber gasker.

[Big IV]

Solder gun and a bit of bedliner? I have a solder gun. Do I have bedliner. Hmmm.

Gasketed up screw could be interesting. I have all the pieces at least.  This has offically become plan B.

New gast tank will be somewhere around Plan C or D. The cheaper the better.

I did find some sonic solder stuff at the auto parts store that says it bonds to plastic, fiberglass, metal, etc. Different than the stuff I usually use which is for aluminum or metal. so I'll try that in the morning when I get a chance. Had to post pone this project until I could get a second set of hands. I want to put a small amount of air into pressure into the tank while I lay under the truck and squirt bottle looking for more holes.  Turns out I can't stick my head under the truck and still reach the air hose in the gas fill hole. Go figure.

[Brad]