Thread: ?s about blade geometry

1 -About the ridges (two parts of the spine that touch the hone) On a razor that has been over honed on the toe (or heel) how important is it to get the ridges totally the same thickness from heel to toe assuming they are still centers on the edge. (.195 at the toe and .199 at the heel, 4 thousandths thicker at the heel)
2 -On a razor that has a frown and has a slightly hollow spine. How do I make sure that I don't remove too much at the heel or toe of the edge. With a straight spine I could measure from the edge to back of the spine, but with the hollow spine I'm not sure what to use as a reference.
How critical are these issues to the blade geometry?
Probably not the best razor for my first restore, but at least I have some nice scales from it. Its a Shumate 127. Besides the frown i think someone rounded off the original point.
Thanks for your insight.

Originally Posted by sgthuskey

1 -About the ridges (two parts of the spine that touch the hone) On a razor that has been over honed on the toe (or heel) how important is it to get the ridges totally the same thickness from heel to toe assuming they are still centers on the edge. (.195 at the toe and .199 at the heel, 4 thousandths thicker at the heel)
2 -On a razor that has a frown and has a slightly hollow spine. How do I make sure that I don't remove too much at the heel or toe of the edge. With a straight spine I could measure from the edge to back of the spine, but with the hollow spine I'm not sure what to use as a reference.
How critical are these issues to the blade geometry?
Probably not the best razor for my first restore, but at least I have some nice scales from it. Its a Shumate 127. Besides the frown i think someone rounded off the original point.
Thanks for your insight.

I think in case 1 you are asking how important is it that the spine is exactly the same thickness from heal to toe. If that was the case, there would be many old razors that would never get honed.

In case 2, your reference is you eye and a straight edge if you like. Hone toe and heal with low grit hone until it smiles at you. circles or back and forth motion with a little extra finger pressure over the are of the blade you want to reduce. Try to spend the same amount of time on each side of the blade to keep things even.

Check out this 1961 barber manual excerpt PDF file from the SRP Wiki help files here. It is on honing and stropping and addresses how to avoid a frown when honing as well as illustrating how to get or to maintain a desirable blade profile. Few razors are symmetrical from spine to bevel, heel to point or from one side to the other. Look at photos in the razor clubs forum and you'll see what I'm saying. You might also want to check out this video here. I took the liberty of moving your thread to "Advanced Honing Topics" where you may get more input. Post a photo of the blade for better assessment and feedback.

I think that all depends on the razor. New blades with close to set angles would benifit from that kind of attention, but if we are talking vintage blades that already have wear than trying to bring in the over all geomitry would end up causing potentialy excesive hone wear.

This is all just my own mental processing so if anyone has additional input PLEASE DO!!!!

Thanks guys,
The barber's manuel was great. I think I was getting too technical on measurements. It just has to look good and work. Looks like someone put some time into getting rid of a spike tip on this razor. When I first put this razor to a hone I noticed it also has a curve to the edge which is probably why it has a frown. It takes some special care on the hone, but I think it will shave nice someday. So far I have sanded it up to 2500, so it now shines nice. Still needs polished. And I have managed to work the frown out, but now I need to get an 8k to work on it any more. Maybe for Christmas. Only have a 1k/4k Norton right now, but it is getting really sharp. Can shave arm hair really nice. I also need to find new hardware to put to scales back on. Its amazing how wrong a razor fills without the scales to balance it. I think it would be ackward to finish the honing without scales.
Again thanks for the help. That was exacty what I needed to know.