Thread: made first straight razor!

Originally Posted by ScottARoush

Is that grind that unique though? I was looking at cross sections of the japanese razors and the only difference is the lack of the 'smiley' from not having the slight hollow grind on the flat side. But, hey! Microtomes are good cutters!

Yeah.. i can't really get a good bead on this grind. It looks MUCH heavier than the kamisori profiles I've seen, and actually (from the pics) looks a bit convex on the flat. This could be the pics fooling me though What size wheel were you hollowing on?

>>> Anyway.. The plan is to take it back to the grinder, put a secondary bevel on both sides, re-hone and then see how it works. If that fails, I will hollow grind the flat side to attain a more true kamasori geometry.
<<<

PMFJI --

If I understand right, a kamasori (if it's like a Japanese plane or chisel blade) should have _no bevel_ on the flat side. All grinding is done on the hollow-ground side (unless a wire edge develops).

But that's related to the extremely hard steel layer that makes up the cutting edge. For your blade (which is evenly tempered), putting bevels on both sides might work fine.

As you say, there's lots to learn . . . <g>

Charles

Originally Posted by cpcohen1945

If I understand right, a kamasori (if it's like a Japanese plane or chisel blade) should have _no bevel_ on the flat side. All grinding is done on the hollow-ground side (unless a wire edge develops).

But that's related to the extremely hard steel layer that makes up the cutting edge. For your blade (which is evenly tempered), putting bevels on both sides might work fine.

As you say, there's lots to learn

I would have to say that the japanese grind style is about the geometry they are looking for, and not a result of their heat treating (which should be proper on any razor for good results). There will be some degree of hollowing on both sides though. During honing, both sides will see some action as well.

okay... I've learned this lesson before with my cutting competition knives but it didn't carry over to my straight razor. Yes... it is 'heavy' compared to the other kamisory profiles. It's going from 3/16" thickness at the spine across only 7/16" of blade! So... I did as I suggested in the other posts and no improvement whatsoever. Therefore... I'm going to grind the hollow ground side to a thinner profile.

By the way... That picture does suggest a convexnessishness. But it ain't there in reality. If there is anything I CAN do.. .it's flat grind. And... I'm using a 8" contact wheel. What do other folks use??

I suppose it would be nice to have actually held a straight razor at least once in my life. But this is fun experiment.

Thanks again for all the input. Hang in there on this thread... a shaving tool might emerge at some point...

I understand about the photos not really showing all of the story about the flat grind ...

As for the contact wheels, for a 6/8 razor, I think using a 3" wheel would get it to be somewhere around a 1/2 hollow (in razor grind terms)... maybe a bit heavier. It's got to be fairly "wedgy" with an 8" wheel on such a narrow blade.

Another thing to keep in mind is that traditionally, straight razors are designed to be honed with the spine as a built in guide (i.e. laying the razor completely flat on a hone touching the edge and the spine.) so the heavier the grind, the more honing work will need to be done.

The big problem you are facing right now is that you are honing totally, completely, out-of-the-ballpark WRONG. 1000 grit is about the lowest grit you will use on a razor... finishing more in the 10K-30K range.

Originally Posted by ScottARoush

Hello folks... I'm a bladesmith (Big Rock Forge - Scott A. Roush, Bladesmith) that forges camp, hunting and kitchen knives and I just tried a straight razor for the first time. I've never even shaved with one and obviously have a lot to learn. I will post pics tomorrow, but basically I started with a 1/2" x 3/16" piece of 1084 and put a hollow grind all the way to the from edge to spine on one side and and flat ground on the other. I put a 15 degree secondary bevel on the flat ground side with a 1" wide 220 grit belt to a wire edge then stropped with stropping board with jeweler's rouge. It just now occurs to me, as I'm writing, that perhaps I should have put a secondary bevel on the hollow side too! Anyway.... the sucker is sharper than anything I've ever made... it shaves arm hair effortlessly and cuts paper with just it's own weight. But it only shaves face hair OKAY. It does good on the side below the temples, but really takes some scraping for above the lips and chin.

So... since I'm new to both straight razor making AND shaving.... I now have at least two variables to contend with. Is it my razor or my technique? As to technique, all I can say is that I've been sitting here watching Youtube videos trying to learn.

By the way... this is very interesting from the perspective of a knifemaker. Really makes you think about edge geometry!

You may understand this better than you think.

Edge geometry is key to sharpening a razor.
Since a razor is honed flat on a hone the
equal bevel uniform width of the blade and thickness
and evenness of the spine define how sharp a
blade will get. An asymmetric shape like yours is
difficult to sharpen.

With knives many sharpeners have special jigs to set
the angle. A razor is its own jig!

Since many folk like wedge like blades you do not
need to grind the blade to a full hollow just a
very uniform hollow. A full hollow grind has a
couple subtle differences to stabilize the edge
that some research will uncover but not the details
that make the best razors so hard to duplicate.

Temper is a key challenge. A razor is harder and
more brittle than knives. This hardness issue is
a challenge for many. Power tools will often overheat
steel and wreck a razor where it might help a blade.

There are some great threads on this so a search will
uncover some good stuff.

Hint give attention to BOTH the bevel and the spine.

thanks Tom....

From what you are saying, it sounds like it would be better to do a flat grind all the way to edge, or a slight hollow grind with edge at same level as spine to allow laying the razor completely flat on the stone... but if you put on a secondary bevel, then you can't simply lay it flat on the stone right??? You have hone it at the angle in which you set the secondary bevel...

As to honing to finer than 1000.... I'm not sure I understand that. If you get a wire edge and then polish it off with rouge on a strop.. you've achieved what you need to achieve right? My understanding of japanese water stones is that you form the edge at the coarser grits and the below that it's a series of polish grits that simply remove the wire edge without stropping. I could be way off base, but that is my understanding of sharpening japanese swords. Having said that, I do believe that honing is my problem. But I have a feeling it's because of my screwed up edge geometry. I'm about to just start completely over and go by some actual dimensions of an actual western styly razor. I reground last night to what looks to me to be a kamisori... and it's worse if anything. Shaves my cheek hair great... but can't get the chin and mustache.

As to temper....Well I know my 1084 and I temper it to 400 which should be something like 58 rockwell which would be less than a commercial razor. but that's just a matter of ease and frequency of sharpening...not the actual quality of the edge according to my understanding. Also... I use a variable speed KMG set at low settings and sharp belt for putting the initial edge on with frequent water dips.... I've never had an issue with losing temper on the belt. But I've sure seen it happen!

Hi Scott,

Some help with the geometry:

Spine thickness: blade width is around 1 : 4, so the blade is around 4 times wider than the spine is thick.

My 2 razors - both around 5mm thick spine, one has blade width 20mm, the other 18mm.

I remembered reading about it somewhere - one of the custom razor makers - so I checked my own razors.

Good luck with the razor making (and using!), keep us posted with your progress.

Michael

Hi Scott and welcome to SRP...

A small hint here: The Forge - Straight Razor Place Forums

That is the section of the Forum we call the Forge, it is for people like you

All the Steel bangers hang out there, and there is a plethora of threads about making razors..

There are some very talented Razorsmiths here, a few came the same route you did by way of making knives, some are only Razor guys...
But one thing they all have in common is the love of sharp steel,,,and the one thing that all of them have learned either easily or the hard way is the Razors and Knives have very very little in common other than the steel...

The thought of a wire edge to a Honemeister is enough to turn our stomach, we avoid them like the plague, the thought of using any power to sharpen with is alien to us...

I highly suggest getting a professionally honed Razor to shave with so you can feel what an edge should feel like on the skin... to those of us that hone razors "Sharp" means nothing, anyone can do sharp, but sharp and smooth that takes talent...

The real difference is the Face Factor most every other sharpened tool is just that, a sharpened tool, a razor has to be dragged across your face... There is a huge difference in the minute differences at the edge...