Welding a gas tank

[corax]

That title got your attention didn't it?

Dammit! Last week I finished the install on my Aux Tank and got the transfer pump all wired up. So I filled it with gas and flipped the switch to make sure everything worked alright, still leaving some in just because - fast forward one week, I get home from a business trip and smell gas



it's a slow leak, probably just a pinhole, behind the mounting bracket - I can see a few slow bubbles of gas from where the bracket meets the tank. Before I installed it I took a good look inside and everything looked clean and rust free - the only rust at all was where the bracket welds were (heat cooked off galvanizing/coating). Since I can't afford closing on the property we just got and buying a new NWMP tank ($630 + shipping), I'm thinking I should be able to weld all the way around the mounting bracket - effectively sealing the leak . . . hold on now, I'm not talking about just running a bead straight to the tank and blowing myself up. The way I've heard to go about this is: drain the tank, rinse with ammonia, let it air out a bit (blow air into it with a shop vac), completely fill with water and then go to town and run a fat bead of weld to it.

-or- I could try to undercut the area between the gap in the welds, clean it and JBWeld it. My only issue with this is that I'm unsure of how long that will hold since gas tanks usually build a bit of pressure in the hot sun.

Any other suggestions or am I just being cheap? Honestly, if I can't fix it, it'll probably end up scrap metal

[X-Tool Pimp]

empty the fuel, fill it with water and weld it up........

[Nick]

JBweld first and see if that works for you. Less trouble and JBweld is VERY strong. One of the wheels on my truck had three pinhole cracks and was letting out air VERY slowly. I JBwelded it about two years ago now and I never loose pressure and I run at 45psi.

[Good Times]

jbweld should work but I'd say if you have the time, I'd fill the tank with water and go to town on the cracked area.

[YotaFun]

I voted to drain the fuel, Fill with water and go to town.

Heck any gas you take out of it you can put right into your other vehicles so your not loosing $$$ in gas.

[CJM]

Water and weld. They also make a gas tank repair putty they sell at the parts store-might wanna give that shot.

[4runnerchevy]

Gas tank puddy works well, I used it once in an emergency (leaf spring through tank thing). I used that same tank for 12 years before I recently went to fuel cell. If I were to weld it I would fill it with water, or just rinse would be fine, open all the holes (filler, ports, etc). Clean, then warm the area with a propane torch, stand back (just in case of flash). Weld it. I have never even had a flash with this method. We used to purge with argon, but not anymore.

[04 Rocko Taco]

Jb weld worries me because even a slow exposure to gas will eventually soften that JB weld, I say fill the tank with water, and go to it.

[corax]

Jb weld worries me because even a slow exposure to gas will eventually soften that JB weld

That I did not know . . . . good info, thanks

[CJM]

^ I found this out the hard way when I tried to repair a plastic weed whacker gas tank with it. Cleaned it up real nice and in 3 weeks the epoxy fell off..

For a temp fix I think you should use the fuel tank repair putty. Then when you have more time, drop the tank and weld.