Removing steam air vent plug on old radiator...

branimal

I drilled it to about 1/4" and then started cutting the plug out with a small hacksaw. Unfortunately I didn't get the hole perfectly centered. I started with a 1/8" bit and worked my way up.

I'm trying to collapse the plug but my cold chisel is to big to get in there. Should I order a 1/4" cold chisel? I tried smacking it with a screw driver but that's not getting me anywhere.

I've applied heat (maap gas), PB blaster and tried an easy out.

When applying heat, should I heat the cast iron or the brass plug?

jesmed1

Heat the plug, because it's smaller and will heat up and expand faster than trying to heat the surrounding cast iron.

Yes, heating and therefore expanding the plug will make it tighter temporarily, but it will also break the corrosion bond, and then when it cools a bit and shrinks back to normal size, you should be able to get it out. Given how much of the plug you've already drilled and cut out, you're most of the way there.

Big Ed_4

I would drill it out , since the hole is not centered , work your way up until you reach threads , the rest should fall out with a little help. Clean out the threads with a NPT tap ….