Questions and Answers
A Question About Gas Tank Soldering
Q. Hello, I know that it can be very dangerous to solder a gas tank with a torch that has a open flame. But, can it be safe to solder a gas tank with a large electric soldering gun? I have a large Sears electric gun which gets hot enough to solder a small hole in a gas tank, but would it be safe to attempt the repair?
If it is safe to do the repair in such manner, I would be using soldering flux and a solid wire solder with the large electric gun. What is your opinion on this matter?
A. I used to work for an old German back in the 70's. He used to drop the gas tank, pour out the gas and let it sit for a while. Then he would light up his torch, pop the flame into the filler fitting. It would make a pop and then he would do his soldering.
But to answer your question, yes, a heavy enough soldering gun or iron will work just as well as a flame. And it is somewhat safer. In fact, I have a 1,000 watt soldering iron I use to repair gas tanks.
What I do is locate the hole and clean an area of about 2" around it. Then I flux and apply solder (60/40 flux core, don't use acid core) to the cleaned area. Then I take a penny and flux and solder it. I put the penny over the center of the hole and heat the penny until the solder melts. When it's cool, I wash it down with thinners and prime and paint the whole area.
Seams are a little more difficult, but with a little practice, it gets simple. The three most important things for a successful solder job is clean, clean and clean. If there is any rust, dirt or grease, the solder will not stick and it will still leak.
Of course this will not work on stainless steel gas tanks but a similar procedure can be used to repair plastic gas tanks.