[Metal Manipulator]

I have a new fuel tank for a car I'm working on and I want to add a drain. I have a steel bung and looking for opinions on whether I should braze it or silver solder.

[cj737]

I’d be surprised if the tank was steel and not alloy. If it is indeed alloy and your bung is steel, that’s not a good marriage of metals near fuel due to corrosion attacking the steel and the galvanic corrosion between the two metals.

If the tank is alloy, get an alloy bung and weld it. You don’t want ANY seepage potential.

[Metal Manipulator]

Thanks for your reply. It is steel, it is a aftermarket tank for a mid 30s car made by Tanks Inc.

[drizzit1aa]

Why would you not just weld it? If the tank is too thin for you then maybe silicon bronze, it with TIG. Like cj737 said, that could cause a Galvanic corrosion. Here is a link to what that is.
https://www.appmfg.com/blog/4-facts-on- ... -corrosion

[Metal Manipulator]

Thanks, I do understand about galvanic reaction. I don't have a tig but I have tig welded some but very little. I don't have enough experience with one to be any good at it. I kept contaminating the tungsten.