RBnDFW wrote:

OK, so I got a deal - Like new 60-gallon Kobalt compressor for $125 on CL.
He said it had a hole in the tank, but he couldn't find it.

So I got it home powered it up, and sure enough, there's a hole in the
bottom It's about 1/16", in the weld area adjacent to the large drain
bung at the very bottom.
Now, this thing looks brand new. I really don't think it's rust
perforation. the paint wasn't bubbled, and there is no rust at the edges
of the hole. i think it was just a porous weld. Anyway, I'd like to fix it.

Here's what I'm thinking: Drill out to whatever diameter gives good
thickness.
Tap it, and screw in a bolt.
Then either braze or silver solder

Better suggestions welcome.

Important things to keep in mind:

- Inspect carefully for cracks

- Avoid any heating process that could change the metal strength

- The force on small holes / plugs is small, so you don't need welded or
brazed connections. Even a 1/2" dia plug at 120 PSI is only about 25#
force.

- Pressure tanks are not magic, so if you inspect it and find it is just
a manufacturing flaw in the weld, and you repair it without doing
anything to compromise tank strength it should be fine.