Thread: Hollow Grind To Thin?

Found a nice $5 6/8 straight razor at a antique store and it was nice and shiny, no pitting, very very little stains in one spot, no frown, very little hone wear and that was after a quick once over before I bought it. Brought it home and tried to hone it, but couldn't get a good sharp bevel from heel to about the middle of the blade. So I took a closer look at the razor and noticed it looked like someone buffed it. So I put the blade edge on my thumb and gave it very little pressure "I stress very little" and noticed that I could see the blade from bevel to about 3/8" flex, but it was only from heel to middle of the blade. My question is how thin is too thin? The blade sounded good when lightly plucked with finger, but on the hone you could tell it just sounded thin and flimsy. Would a secondary bevel strengthen it enough or would completely removing the bevel and starting over work? Or is it just a nice letter opener?

Got a Mic?Measure the section that flexs as opposed to the area that do's not.

I didn't even think of that. What do you think is too thin and if it does happen to measure the same would that mean the temper is off?

Perhaps either or,don't know,sorry.

Its difficult to really determine if the temper has been comproised just by the blade flex or sound. Although 3/8" does seem to be excessive on a 6/8 even for a full hollow. Assuming that you have a good bevel set, I think I would go back to the hones. Perhaps 4k/8k. Don't waste time at higher grits until you have it shaving at least. Possibly increase your bevel angle very slightly and try to get it "sharp" or to shave arm hair. You may also look as you are honing and see if you notice the residue of fine metal coming off at a faster rate from heel to toe. If after some initial honing you may want to go to the canvas and leather just to clean up and see how your coming along. A 60x loop may also be of some help in this situation if you have one. Just a few thoughts here. Blade tempers can and do vary greatly with razors and as to how thin is too thin? Well, not sure I can answer this definatively but many 1/2 to full hollow ground razors can be as little as 0.20 mm. Not sure if this helps you much. I think more often than not its just a matter of working until you get it just right and on rare occastion, you have a bad one that just wont get shave sharp or won't hold and edge for any length of time.

Best Regards Kenny

sorry I meant 3/16" flex and thanks for the response. I was going to use 1 layer of tape and see if that helps. I'll keep at it and see how it goes. If nothing else its a learning experience.

No problem, 3/16 makes more sense. Sounds to me like you are at least on the right track. If something is not working it never hurts to switch things up a bit and try something different. If you get it shaving, you can then get a better idea of how long it will hold an edge when put to use. If you find it failing after a handful of shaves or even one, then it may be an indication of lowered temper. Of course not definitive evidence, but certainly possible.

Best Regards Kenny

If the previous owner was a little to heavy handed with the buffer, it very well might have blown the temper. It doesn't take very long to do it.

Actually the flex is something that has been sought after. This test has been called "Nagelprobe" in Germany, especially Solingen.
The word is German and literally means thumb nail test. The blade was tested during the hollow grinding stage if the grind was thin enough
by looking for this flex. So actually it was a good thing and Dovo as well as Mr. Wacker still use this test, as far as I know.

I don't think the hollow grind may be too thin but maybe the geometry of the blade got screwed up.
You should definitely check if your stones have contact with the entire bevel (marker test) and hope for the best regarding the temper of your blade



image courtesy of
http://www.wacker-rasiermesser.de/im...llung7_510.jpg

Thanks for the picture I tried taking some to show the flex, but couldn't get it to show on the pictures. The razor flexs like that from heel to middle of blade. As for marker test whole bevel hits.