Thread: Reshaping the tip

I actually just repaired one from LarryAndro not unlike that one you have. I did it on a very coarse synthetic bench stone by hand, it only took a few minutes and I didn't risk breaking or cracking the blade like you would with a high torque grinder. Anything with a motor, even a low speed grinder, could get out of hand and either change the temper if it gets too hot, or risk breaking or cracking the blade.

Before:


After: I have since rounded off the angle a little to make the lower part of the damaged area useable.

While the tormek would work, it would also take forever to finish. For a first I don't see why that would be a bad thing. I prefer cut-off wheels for large removal and my belt sander for reshape.

Originally Posted by HNSB

Don't run the grinder perpendicular to the thin axis of the blade. It might take out big chunks if you do.

What do you mean by this? thin axis = blade to spine or = heel to toe?

A) Don't lay the razor flat and push into the face of the grinder?
B) Don't lay the razor on its spine and push into the face of the grinder?

Originally Posted by UPD

Anything with a motor, even a low speed grinder, could get out of hand and either change the temper if it gets too hot, or risk breaking or cracking the blade.

soo... its a water-cooled stone... would using icewater cool the stone better or would it damage the stone?

Originally Posted by deighaingeal

While the tormek would work, it would also take forever to finish. For a first I don't see why that would be a bad thing. I prefer cut-off wheels for large removal and my belt sander for reshape.

I think I might try the cut-off wheel on a block of ice trick to roughly get it right, then finish it up on the tormek.

I don't know if an old gunsmithing trick for welding new gucci bolt handles on a bolt might work. They filled a coffee can with sand with the bolt face to the bottom - In this case the shank.Coffee can was filled w/ water, keeping the entire submerged bolt cool from the welding torch. The issue might be the sand not having the holding power required as you run a rotary cut-off wheel on the tip. This might require that a 3lb can be used so there was room to reach in and hold the spine below the water level while the tip was cut off before shaping.

Another tip from the same source was about the cut-off blades for a dremel or foredom grinder - they shatter alot less (need I talk about eye protection?) if you superglue two of the discs together.

Instead of a Dremel, consider a dog toenail grinder. The on we have is 12 V with variable speed, and it's clutched so that you can't accidentally rip the fur from between Spot's toes. It can't run fast enough to really heat up a blade, nor crank up enough torque to get too dangerous. It might not be powerful enough for cutting; I haven't tried it for that.

I think if you tape all but the last inch and a half of the blade for safety, hold it edge up on the grinder rest with your fingers on the untaped part, and dip it in water after every few seconds on the wheel or belt, you won't overheat it. Water requires nine times as much heat to raise it by one degree, as the same volume of steel does to reduce it by one degree. So whether the water is icy makes very little difference.

But if you prefer it, jewellers have a heat absorbent gel which they apply to delicate parts of objects they are soldering.

If you use a sharp cut-off wheel or a wheel drum with a fresh drum, you generally will not overheat the blade, because the metal that starts heating up will be removed quickly, before much of the heat has a chance to spread to the rest of the blade.
It'll still get warmer of course, so check the temperature, but it does not happen as fast as you think it would.

Originally Posted by 96firephoenix

I've done plenty of grinding before, but I'm by no means a machinist. I've got access to my dad's tormek water-cooled grinder (low RPM, 600/1000 stone), which would be my obvious tool for this, compared to our belt sander or garage grinder (high rpm, 100 stone).

Is there any special technique to grinding razors that I should learn first or is it just a matter of take it slow? I know the saying haste makes waste all too well, and I really don't want to make waste of this razor.

BTW, i've cleaned it up since that picture was taken

I have a 1908 Geneva 4/8 that had a chip/notch like what you illustrated. I was able to "grind" it out simply by shaping the toe by hand on a 220 grit stone. I went a little at a time so that I can achieve an even radius. It took a while but it paid off.

I'm afraid you might lose some blade length if you grind that out to a radius. Perhaps you can reconfigure it to become a barber's point. I'm by no means an expert here, I am just offering up my opinion and observation.
Good luck on your restoration.
Patrick

Check out the tip at this post. It turned out to be a regrind, and a darn cool one too.

Got the blade in the mail from LarryAndro.



not as bad as the Yankee in the original picture, but the chip is still pretty good sized:


gonna re-shape the tip on the tormek, with a glass of ice-water on standby for dunking about every 5 seconds.

results: