Is that better than commercial penetrants like PB Blaster, or is that just one of those things mechanics tend to use because they have it sitting around I have a 100 year old cast iron screw jack, massive thing, that I am trying to free the screw up. PB soaks right in, hesitant to use heat because cast iron.

I have taken a cheap socket, jammed it on and tacked it with a wire feed welder.

Worked that time.

For a stuck bleeder on a good caliper, I had a small jeweler’s torch, MAPP and oxy, heated it up hot, not enough for cherry red, and the trickle water on it, and the thermal expansion broke it free.