I dropped my gas tank this weekend to replace the sending unit. I drained it best I could, but there was still a half-gallon or so sloshing around inside. When replacing the non-ground wire on the sender, the little copper stud the connector slides onto broke. No way was I going to order a new sender and go through the hassle of hammering it in. I spotted my propane torch on the workbench with a soldering tip on it and thought about it for a second, but figured it probably wouldn't be wise. I ended up putting a ring connector on a wire, clamping it as best I could to what was left of the broken stud and gooping a pile of hot glue over the repair. It seems to hold OK so I put a connector on that wire and one on the original wire and it works.

 

I'm amazed you got it this low. The two times I've dropped a gas tank (the same one), I wasn't able to get it below 3 or 4 gallons remaining. I just lowered the tank carefully and poured it out through the filler neck once the tank was off the car.

Your story reminds of the famous last words "gimme a match, I think my gas tank's empty."

 

If you can pull the tank welding it is not such a big deal, if you follow these steps

#! Drop tank and get as much of the gas out as you can ,That means all of it.

#2 Flush the tank several times with a strong solution of dish soap and water. Shake the tank a bunch.

#3 Add water to the top of the filler lid but do not' put the back on lid on or bad things can happen.

#4 Weld it up from underneath if the hole isn't to leaky. if to wet turn it upside down and with a tight rag and a stick in the neck filled to the top with water weld it up or braze the hole( I've had better luck with welding but your mileage may differ Dry it out and reinstall.... Tedd

 

Your lucky, it could have been another one of those WTF was he thinking moments!

 

Always a good moment when you think, Well maybe I won't be that guy Then you think about the news headlines, Guy in garage decides to take a torch to a filled gas tank... Police looking for a suicide note now. Nope never been there before

 

It's not the filled ones that make the largest explosions, it's those with a small amount of fuel and alot of vapor.

 

Years back, I saw a tank that was being worked on shoot a crossed the shop like a rocket because it wasn't prepared properly. Blew open one end of the tank and it took off when the mechanic touched the torch to it to do some soldering. Just lucky no one was hurt.
stetzie

 

I think they really are supposed to be filled with Argon gas first before welding on ??? Some inert gas I can't remember.

 

I have soldered a fairly new ,clean , galvinized gas tank with it filled with water when I was young, with a propane torch. Do not know if I would do it again.
I did recently solder a ground wire to my removed sender with a solder gun.

 

After flushing it with water and dish soap a few times couldn't you just let it sit out in the sun for a few days? Maybe blow it out with compressed air too? Wouldn't that take care of any fumes that are remaining?

 

I heard a story about a guy that repaired gas tanks & he always piped the exhaust gas from a lawn mower in to the tank for about 1/2 hour before repairing it. He said the exhaust gas displaces the gas fumes & also is very low on oxyget content to further reduce the chance of an explosion. He said he never had a problem.

 

That would make it a bench top exhaust ignitor kit. <poof>

 

Guy I know blew up a tank welding once.

He was welding a car on one side of the garage, and the tank was on the floor under a workbench on the other side of the garage, and hadn't been used in (I think) a year or more.

Tank blew up, he had no idea WTF had happened. Fortunately, it was on the other side of a 3-car garage, so he wasn't hurt.

Punchline is the guy was a fireman, and obsessed with fire safety.

I had my tank out last month - got all the gas out, mopped up the residue with paper towels, then let it sit in the sun for a day, then left a heat gun wedged in the sender hole for half an hour, blowing full-on, and afterward it didn't smell gassy.
Don't know if I'd want to try welding it, though...

- Eric

 

Back in the day( I was probably 17) I worked in what would be called a real blacksmith shop. This shop had a reputation for welding up gas tanks from the local farmers and 4x4 clubs, we did them on a daily basis. After welding we would set the tank on a forge that was almost out and dry the thing out .Not a problem if you followed the steps shown above( don't skip any steps or bad things will happen.....Tedd

 

You're all missing the point. The O.P. wasn't welding the tank, he needed to solder to the connector on the sender. The easy and safe solution would have been to simply remove the sender, wash off any fuel residue and thoroughly dry, and THEN solder to the terminal.

 

Argon may work i dont know but i think they use CO2, My late father in law told me he stood in 2 feet of gas in these huge storage tanks welding cracks from the inside. They would flood the tank with CO2 and send the welder in with an air supply so he could breathe, just straight air. He said it was no problem.
I wouldnt do it!

 

Any non-flammable or inert gas would work fine.

That includes the noble gasses, CO2, CO, and N2.

But I do have to concede that we've gone a bit far afield.

- Eric

 

Radon might work to keep things from exploding, but I'm not sure you want to work with it (Sorry, just trying to go even farther afield!)

 

Wonder what would happen if you used a halogen?



- Eric