rlitman
Well-known member
I'd definitely be using the torch..... It is surprising on how the torch will heat just the tap or a broken bolt and to a lesser degree, the metal around it.... The small bits will get cherry hot.
It's less about using skill and more of just a steady hand.
If you are concerned about the process.... Try a practice piece. A long coupling nut, clamp it in the vise, thread a bolt in thru the bottom. Then try burning out the bolt from the other side. Worse case, you are out the $5 for a coupling nut and a random bolt.....
Here's what I've got with regard to pros/cons for the torch.
Pros:
It works, and is quite effective.
It is hard to mess up. Really, it sounds risky, but the tap will heat up in just a few seconds, and it takes many times as long to heat up whatever it's stuck in, so it's actually low risk.
Cons:
You must have an oxy-acetylene torch (we're past that here).
It's not so great in a recessed hole.
And that last one may be a problem. The issue is with exhaust. The whole of the flame is significantly larger than just the visible cone. Against a tap that's flush, or only barely recessed, you won't have any trouble putting the inner cone against the tap. But in a deep recess, the flame needs room for the exhaust to escape, and you may end up with a popping and sputtering flame that won't pre-heat the tap.
Once the tap is pre-heated, only the oxygen stream does the work, and there is no exhaust gas to speak of, so the tap will burn to just about any unlimited depth. But getting it started in a deep hole may not be possible now that it's been drilled.