Thread: Grinding razors

Originally Posted by Mike Blue

Starting with a flat bar of your favorite steel, you have to remove everything that doesn't look like a razor.

That can be accomplished with what ever method, belt, disk, files, chisels, stone wheels you choose. This part of the process does not make any difference. Really, just use the tools you have and get good with them until you can afford better tools that do the job more effectively. You can abrade away material to your heart's content at whatever speed you wish. Grinders will heat up the steel and turn it all sorts of colors, but by that time it will be too hot to hold anyway.

Once the blade has been heat treated, then grinding can dictate a different approach. You don't want to get the blade hot enough to temper away the hardness of the blade.

Wet grinding addresses the problem of heat generated during abrasion and helps to protect the investment put into the heat treatment. You can use a belt grinder running at a slower speed, aka variable speed. But, have a bucket of water handy and work with your bare hands so you can feel the moment that the steel is warming up and cool it right away.

Files are good steel for the most part, IF they are old ones like Nicholson or Black Diamond. Some of the new files are case hardened mild steel and should be approached cautiously. Grinding a blade from a hardened old file will be more work since you have to grind away hard steel and you have to attend to the heat problem if you don't want to lose that hardness. It will take longer in terms of time invested.

u tellm mike
harley
luke sky possum

I am grinding my first razor from an old file. I have the perimeter shaped and have started to grind the bevel. The blade is between 6/8 and 7/8 wide I am using an 8” wheel. How thin/thick should I leave the edge before hardening? What liquid would you use to quench an old file?

Thanks for putting up with my questions.

Charlie

Originally Posted by spazola

I am grinding my first razor from an old file. I have the perimeter shaped and have started to grind the bevel. The blade is between 6/8 and 7/8 wide I am using an 8” wheel. How thin/thick should I leave the edge before hardening? What liquid would you use to quench an old file?

Thanks for putting up with my questions.

Charlie

i first grind w an 8 in wheel but leave it VERY thick .100
then heat treat ti
then finish grind on a 3 in wheel
as to files??
mystery metal!!!!!!
mabey 1095 mabey not
quinch in oil at about 1450
but then again
i dont know much about razors
harley

Charlie,

For your first blade, I'd suggest .050", or about the thickness of a dime. Thinner means less hardened steel to remove after heat-treating, but you also have a greater chance of cracking the blade.

How will you be grinding post-heat treat? You really have to watch getting the blade too hot, or you'll ruin the hardness.

For oil, I would try veggie oil from Wal-Mart. Preheat it to 130 F before quenching.

Josh

I will grind with a 1X42 belt with an 8” wheel, or a water cooled grinding wheel mounted on an arbor. I am not sure yet. I have not made the 8” contact wheel or rigged up the arbor yet. I will wait till this weekend and see which seems easiest.

I am roughing the hollow/grind out on an high speed 8" grinder

Thanks for all your guys help, I really appreciate it.

Charlie

Just a little update...the wheel size makes a lot of difference when grinding. In an earlier post, I stated I do most of my grinding on an 8-inch wheel. That has changed. I'm going for a bit more hollow lately, as they're much easier to use, if harder to grind. My goal is ease of use for the end line user, so I've gone a lot to a 6 and 4 inch contact wheel, and I've been very happy with my results so far. I've even converted some earlier grinds to the more hollow, and with the smaller wheel, I don't get into the spine as much.

I will usually leave my blades between .050 and .080" before heat treating. I like to leave thick to prevent warping. Taking off the hardened steel after heat treating isn't hard, using belts like Norton Blaze or SG ceramic belts. They're expensive, and worth every cent, as they'll outlast an aluminum oxide belt 10-12 to 1.

I don't recommend using vegetable oil, preheated or not. It might work, but I would like a faster quench, to insure maximum hardness. You want the steel to get its absolute hardest it can be in the quench, then temper it back from there. Bacon grease would work better, since the salt in it speeds up the quench a bit. A good mix for quenching is bacon grease, beeswax, saltpeter (anecdotally, adds a bit of nitrogen to the blade, and that's a good thing) and transmission oil. You can actually mix this to where it's a solid at room temperature, and use it that way (or you can preheat it), and it works very well (thanks to Wayne Goddard for this "goop" quenchant). Pretty cheap and easy to make, too.

Thanks for that JC. So you are saying that you find the grinds with a 6 or 4" wheel are easier for the shaver to use? As in an easier shave and easier to hone? At the same time though, they are harder for you to grind? I just want to clarify that.

Originally Posted by Joe Chandler

Just a little update...the wheel size makes a lot of difference when grinding. In an earlier post, I stated I do most of my grinding on an 8-inch wheel. That has changed. I'm going for a bit more hollow lately, as they're much easier to use, if harder to grind. My goal is ease of use for the end line user, so I've gone a lot to a 6 and 4 inch contact wheel, and I've been very happy with my results so far. I've even converted some earlier grinds to the more hollow, and with the smaller wheel, I don't get into the spine as much.

I will usually leave my blades between .050 and .080" before heat treating. I like to leave thick to prevent warping. Taking off the hardened steel after heat treating isn't hard, using belts like Norton Blaze or SG ceramic belts. They're expensive, and worth every cent, as they'll outlast an aluminum oxide belt 10-12 to 1.

I don't recommend using vegetable oil, preheated or not. It might work, but I would like a faster quench, to insure maximum hardness. You want the steel to get its absolute hardest it can be in the quench, then temper it back from there. Bacon grease would work better, since the salt in it speeds up the quench a bit. A good mix for quenching is bacon grease, beeswax, saltpeter (anecdotally, adds a bit of nitrogen to the blade, and that's a good thing) and transmission oil. You can actually mix this to where it's a solid at room temperature, and use it that way (or you can preheat it), and it works very well (thanks to Wayne Goddard for this "goop" quenchant). Pretty cheap and easy to make, too.

Yiks!! Saltpeter... how much are you using in that mix? Hope it's a small amount.
Saltpeter releases oxygen when heated (gunpowder).
The O2 will combine with the iron (iron oxide) or the carbon in the oils (CO2).... are you still there?

Originally Posted by Philadelph

Thanks for that JC. So you are saying that you find the grinds with a 6 or 4" wheel are easier for the shaver to use? As in an easier shave and easier to hone? At the same time though, they are harder for you to grind? I just want to clarify that.

Not sure if the shave is any better. Guess that depends on what you like. It would be easier to hone, though, as the increase in hollowing makes it so. They are a bit harder to grind, because the thinner you get the metal, the faster and easier it picks up heat, increasing the susceptibility to burning, so you can't get by with dull belts at all, and you have to go really slow. The results are worth it, though.

Originally Posted by smythe

Yiks!! Saltpeter...

I read somewhere that urine in combination with fat/grease was used for quenching "in the olden days" due to salt and nitrate content... Can't find the source again now though