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My first two razors, ready for heat treat
Hi everyone, just wanted to say how excellent this forum was, and to share with you my first razor project.
I learned a lot from reading through the archives here about how to make a razor. I'm not claiming that I do know how of course, but reading stuff here answered questions I had and surely saved me a ton of time with trial and error. So now I've got two roughly razor shaped hunks of metal, ready for heat treat.
Based on various threads here I opted to start out with O1 steel since its cheap, relatively easy to work, and by all accounts performs well as a razor. I got a bar of 1x0.250" from Jantz for like $15, which is enough for 3 razors!
I think the idea expressed here of "remove everything that isn't a razor" is a good guiding principle. I have a decent machine shop at work which I can use after hours, so I've been using the kinds of tools you find in a machine shop. I made myself a jig to hold my blanks at an angle to allow easy milling to get the rough taper angle on the blade part, and bought a carbide insert mill off ebay. Between the mill, metal bandsaw, sanders, and a buffer, I've managed to get the shape about right. I ground the hollows with a 6" rubber sanding wheel I bought from Caswell.
On one blank the edge got a bit thin perhaps for O1 pre-heattreat; about 1.5mm. The other one I made a little thicker, so the edge is 2mm. The handles are milled down to about 4.3mm. Hopefully they won't warp. The first one took a while since I had to figure out what I was doing, but the second one took only 2 hours to go from blank to the state in the picture.
One downside to O1 is heat treating. On the plus side its simple enough to do yourself, though I don't feel up to that at the moment. But it does seem less predictable than some of the air hardening steels, which I could just send out to one of the knife supply companies to do. After reading here, I'm going to PM someone off this board to see if they will do it for me.
Anyway, I'll let you know how it turns out!
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Back from heat treat - commencing secondary work
The two blades came back from Mike Blue yesterday and they look sweet. Mike said everything went fine. I got my grinder at home set up with my Caswell rubber sanding wheel and a VFD, then did a little grinding. A few snags:
- didn't realize that almost all VFDs will trip GFI circuits. I've got GFI outlets in the basement. But after I got that straightened out...
- the sanding loop won't get clamped by the rubber expander wheel unless its running at around 1800rpm or above
So I just started grinding at 1800, switching the razors in and out of a tub of water so one is cooling while I'm grinding the other until it gets hot. Hopefully I won't mess up Mike's nice heat treat.
By the way, do you grind with the edge facing up and into the wheel all the way to an edge? It seems like when you are getting close it might make more sense to flip it over and have the edge trailing. What is the best way?
Also, you really take it all the way to an edge? Seems like it will be tricky to avoid overheating as I approach the edge.
Thanks for the help everyone,
-Holly
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Done - but won't get sharp!
Well, I've gotten to what I was hoping would be the finish point with these two razors. Definitely learned a lot. A few thoughts:
- My 40 grit belts for my 6" expander wheel last about 5 minutes before the metal removal rate starts dropping off quickly. It took me a few hours of mostly wasted time using belts which felt gritty to the touch but in fact were not cutting the metal much. These are just cheap aluminum oxide belts, and they are only 18.9" long so it makes sense they give out faster than a quality 72" long belt on a real grinder.
- I didn't realize it at the time, but apparently I had a hard time not grinding too much in the center. I was sweeping the blade back and forth over the 1.5" wide belt, trying to slightly increase pressure at either side to compensate for the fact that the middle was spending more time in contact with the wheel. When I tried to start honing, this problem became very obvious. You can see it easily in the size of the bevel in the pics.
- Razor #2 (the one with the more rounded point) ended up with the edge not parallel to the spine. So when I started honing it I saw that on one face, the nose end edge was touching but not the heel, while on the other face the heel was touching but not the nose. Probably this is partly due to the fact that I left the edge much thicker on this one before heat treating, so it had to endure much more of my inexpert freehand grinding. I think next time I would use calipers to scribe a line in the heat treating blue coating where the centerline of the blade should end up and check frequently how close I am to it from each side while grinding. I tried to fix this problem by just grinding more at the edge, and then by taking tape off and allowing some of the spine to get ground. Eventually I got at least a small amount of bevel to show everywhere.
- Though it looks cool, mirror finish is a bit of a nuisance. I didn't spend enough time on mine to eliminate all grinding marks, but even at the level I am at any little scratch shows up extremely well. I've rebuffed these a couple times after getting some scratches from stray abrasive slurry presumably pushed around by my fingers during honing.
I've spent a bunch of time honing these, but I just can't seem to get them sharp. I'm using a norton 220/1k, then a norton 4k/8k, followed by a CrOx pasted webbing strop on a flat surface. I would consider myself a beginning honer, but I can hone my one other razor (a kamisori of unknown origin) to a usable level of sharpness, and did do this alongside the two new razors starting at 4k. The kamisori came out ok, the two others just are not getting sharp.
I did try the #1 razor (more square point) after honing it last friday. I could tell it wasn't as sharp as my kamisori but I shaved with it anyway. Boy, it was very different than the kamisori, which is the only other razor I've used. Much heavier and bigger, though somehow smoother, and certainly being able to use both sides of the blade made shaving a lot easier! But it was dull enough that I had to use too much pressure and got some irritation and a substandard shave. I decided to rehone it, after buffing out some scratches I had put in the finish during the first honing. But after the second honing it was even duller.
So I can see two possibilities here:
1) I am not honing these well
In this case maybe I would send them to an expert to see if they could do anything with them. Mike did turn them into bainite, which he warned me would be abrasion resistant and thus hard to hone. But at least looking at the bevel under a loupe during honing, I feel like I am indeed cutting the metal.
2) I wrecked the heat treat during finishing
In this case I would send them back to Mike Blue for retreating and hope for the best as far as warping and decarb go. I'm pretty sure they did not get over 100C during finishing, but my fingers were not right on the edge so maybe the very edge did get too hot. Didn't turn colors at all that I noticed. Still I wouldn't be surprised if I messed it up somehow, perhaps while I was trying vainly to get my dull belts to cut.
Any thoughts?
Thanks for all the help everyone,
-Holly
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The improved edge on razor #1