Get amongst it. There’s something really special and satisfying about precisely controlling a molten puddle in complete silence. I go through about 3 bottles of argon a year welding in my spare time to keep the rust off.
Dan might be right. Pull the plug, clean the area where it screws in down to bare metal.
Run a pencil around the rim of the hole. It’ll show a crack if there is one
I’m no expert but I don’t think he could have cracked the head with that cap since it’s not tapered threads, which is why it has an aluminum washer. However if he puts a plug in there that will be a real issue to watch out for.
Good call, I just always assume pressure threads are tapered because I’m used to them being made stateside. That makes sense though, it’s a General Pump and most of their stuff comes with BSPT
The 2 different thread styles is to form a lock thru tension so fittings dont backout. And the Teflon tape keeps the threads from stripping when changing fittings on the soft brass manifolds. So always use tape there.