Mushrooming, heat and pound?

V

vcbvcbvcb

Joined
Aug 1, 2012
Messages
633
Any body ever tried heating and pounding the mushrooming back on a pole, rather than grinding? I have some very close to a makers mark, and grinding it might damage the mark. I was thinking about heating it, hammering it back out of the way and then grinding it off. What say you?
 
I've done it cold, seems to save at least some of the material. That's a good thing in my book.
 
Square_Peg has, or will have, good tips on how to proceed with this. Involves mild heating and patient/careful pounding. Well worth giving it a shot but don't expect miracles and don't figure on perfectly re-shaping things.
By the way the end opposite the blade is "poll" and not "pole" even though "pole-axe" has featured in English vernacular for a long time.
 
Yeah, you can do it. I do it for just the reason you state - to save the stamp. You can get most of it back at low heat. Recall that the poll deformed cold.

Heat the poll only with a propane torch just until it's uncomfortably hot to the touch. That won't affect the temper. Then hammer with blows slanted slightly away from the stamp. Sharps curls of mushrooming should be filed off first. Then hammer. The hammer will remove most of the file marks.
 
Square_peg said:
Yeah, you can do it. I do it for just the reason you state - to save the stamp. You can get most of it back at low heat. Recall that the poll deformed cold.

Heat the poll only with a propane torch just until it's uncomfortably hot to the touch. That won't affect the temper. Then hammer with blows slanted slightly away from the stamp. Sharps curls of mushrooming should be filed off first. Then hammer. The hammer will remove most of the file marks.
Click to expand...

This is good, straight forward how to. Thank you.
 
Remember that a poll that has been essentially cold-forged twice (the first being when it got deformed) will suffer from some metal fatigue and won't have it's full integrity. But mostly the poll is there as mass to counterbalance the bit. Any filings you leave on the shop floor are gone forever and can't counterbalance the bit anymore.
 
A 14-16oz ball peen should work work great for this ( just for the overall weight and size of the regular head , not necessarily the ball end )
 
I'd go heavier, like 2 pounds. You want the blow to penetrate. And yes, of course, an anvil or other heavy steel under your work.
 
I did this with a single-bit Kelly Flint-Edge. I just put it on a section of rail and hit the mushroom with a heavy hammer. I did it cold. I figured that it moved cold to begin with so couldn't it move more?

Yes, it might work-harden when pushed around, but you will not be abusing the poll like it was in the past, so make it look good and forget about it.

I fixed mine in this manner because I did not want the axe to lose weight and I wanted to restore it's original dimensions and shape as much as possible.

I think it worked well. Make sure you wear hearing protection!

Heating a piece of steel like this with a propane torch is a waste of time. Any heat low enough to not affect the temper of the steel is not going to make it any easier to shape.

Last details, this would work best with a non-hardened poll of course. A poll that has been hardened is likely to crack or chip.
 
Steel loses about 5% of its strength at 100C (boiling point of water) and 10% at 200C, still below the tempering temperature. It's not a great difference but it’s something. I've seen structural steel trusses fail in a fire while the wood glu-lam beams supporting them still held (wood is a good insulator).
 
I have a "pin punch set" with the largest one being 5/16". I was thinking about heating it and using the big one.

 
I've repaired a few polls with cold work. The biggest issue is if there are any cracks in the mushrooming, as leaving the material will make it easier for the crack to keep propagating during the cold forging, so sometimes you have to make a judgment call. But in most cases even pretty significant mushrooming can be pushed back cold as long as you take your time with it.
 
You must log in or register to reply here.
Back
Top