Here’s a carriage bolt that has to come out and the nut is stuck hard; the spanner merely rotates the bolt. This causes much “ vexation of spirit”.
(I am quoting from “Practical Blacksmithing” Vol 2, complied by M T Richardson)
Here is a pair of pipe grips I have modified to grip the head of the carriage bolt.
This is what a polly is supposed to look like.
I have neither the patience, the need nor the skill to make that.
. The prongs have been sharpened, although you can’t quite see that, it seems.
the first thing to do is to drive the lower jaws into the wood, by hammering on the end of the rein.
hammer the top jaws in on the other side, striking the back of the grips. This enables me to grip the bolt’s head firmly enough to remove the nut.
Here is a view of the jaws, although I am sure they are more symmetrical, it must be the light!
To spread the jaws, I put it in the forge, and bent them a bit inwards, a bit too much, it turned out, but a bit of filing remedied it. It’s normalised, I don’t suppose I shall harden it.