Pin hole in plastic gas tank (1 Viewer)

[workingdog]

I have a large plastic (roto molded) fuel tank in the back of my FJ40 with a pinhole. Looks like it was nicked by something last time it was out.

I've read it can be repaired with epoxy, and JB weld and even bondo - anyone here have any experience? I'd rather not have to take the tank down and empty it. The pin hole is in an easy to reach location.

 

[rkymtnflyfisher]

can be repaired with epoxy, and JB weld and even bondo

Only in West Virginia!

 

[47coeman]

I have herd that you would put a screw tightly to fill the hole in it and top it with epoxi let it cure and good to go.

 

[workingdog]

I had her that too, this is on a corner - I was thinking that would make it tough.

 

[Downey]

My Downey tanks are roto molded, and I'm told nothing will adhere to them. When we screw-in the top breather hose fittings we use J.B. Weld as a thread sealer, but that's on the roof of the tank where gas does not live 24 hours a day. I'm told that J.B. Weld holds up the best to gas, but would eventually break down in a few years. I would still go with the idea of a screw screwed-in tightly with J.B. Weld, even in a corner. With roto molding corner or flat surface makes little difference, it's still a one-piece seamless molding.

 

[70fj40]

For a pinhole epoxy putty works well. It will conform to the plastic texture and holds up well once it sets up. Like steel once cured.

 

[workingdog]

I believe this is a downy tank.

Do I have to get it completely empty, or can I make this repair with the tank mostly empty and the gas cap off so there is no internal pressure. Should I gouge out the whole little deeper so the Epoxy has someplace to bite, or just slather it over-the-top.

 

[Ian Macdonald]

Try Seal-all. Worked on mine (so far...) My tank is steel - not sure if that makes any difference. I'm not sure of a lot of things anymore

 

[bj40green]

Use a screw with a fiber washer.

Rudi

 

[Downey]

I believe this is a downy tank.

Do I have to get it completely empty, or can I make this repair with the tank mostly empty and the gas cap off so there is no internal pressure. Should I gouge out the whole little deeper so the Epoxy has someplace to bite, or just slather it over-the-top.

I would not ream out the hole any larger at all, just drench the hole and your tight fitting screw in J.B. Weld, thickness of the JBW does not matter, all of the bonding will take place in the tight fitting area where JBW is the thinnest. Yes, drain tank, then let set up for 24 hours.

 

[BeeJii]

If the tank is PE-HD plastic, it could be plastic welded. That should last as long as your tank when done correct!
Any plastic welder could do it. You could even do it your self if you practise a little first.
I have welded a small extra fuel tank for my motorbike. I got one of those plastic fuel jugs (they are mostly PE-HD, so you could cut those up for your welding "rods") cut it up and welded it back up in different shape. It holded up good and it wasnt too difficult either after a couple nights practise!

edit:
Video clip to show the idea!

 

[workingdog]

Thanks - not sure where I'd find someone that welds plastic around here, but I'll look into it. Hate the idea of dropping the tank.

 

[BeeJii]

Look from auto body shops, they usually can weld plastic.

 

[workingdog]

Cool - thanks.