Flat Grind with hollow Grind on Edge?

RyanW

RyanW

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I have a piece of SanMai from Mike Turner, it is a beautiful piece but I didn't realize the 1095 Core was thin and made to be hollow ground so that the core is more "Exposed". I have already flat ground the blade...

Has anyone done or have examples of a knife that was flat ground then put a short hollow grind around the cutting edge?
 
I don't understand why you need the core to be more exposed... even if the core was only .040" thick you would still have a 1/4" or more exposed for etching. I am not a hollow grinder, so there may verywell be hollow grinding "specific" damascus that I am not aware of. I'm interested in the more experienced responses. Sorry I couldn't help.
 
Thanks for the reply Rick, I believe it was made specifically to be hollow ground, It is actually Chainsaw blade/1080 Powder Damascus with a 1095 Core. The damascus mixes in with the core when it is so close to the cutting edge. I am not a big hollow grinder either, but I think it will push the core up higher on the grind (Does that make sense?). I have example of the Steel but the core is much lower hopefully this will help show what I mean

The black like I drew in is where I anticipate the core to start...
Hollowexample.jpg
 
Sounds like a funky grind to me.

To be clear, what I mean is it sounds like you're planning to do a funky grind for purely aesthetic reasons. I wouldn't do that. Grind damascus like you would any other steel, and let the pattern show what it shows. Don't grind it funky just to make it show something else. The visual result will not be predictable, and would likely reduce the utility of the blade.
 
Alot of the straight razor guys do grinds like this. You could probably use something like a 3" wheel to hollow the lower area.
 
I would suggest the opposite. Hollow grind on the largest wheel you have, if you want to raise the borderline.
 
bladsmth said:
I would suggest the opposite. Hollow grind on the largest wheel you have, if you want to raise the borderline.
Click to expand...
That's what I was thinking. I don't do hollow grinds, but I do understand geometry.. buy a 48" radiused platen from Nathan and you're set!
In fact, it might just be the perfect grind for that blade. Looking forward to seeing it finished.
 
+ 1 on the big wheel. It will be hard enough to control the grind with the big wheel. A small one would be almost impossible. The hollow grind on top of the flat grind is going to lesson the ability of the blades edge to absorb shock. Why not a steep flat grind? If you grind at 8 or 10 degrees off center line You are going to reveal more of the core material.
 
Thanks for all the input, I have a 10" wheel. I am still on the fence with this, Brian - is that Nathan the Machinist that sells radiused platens?
 
For a task like this a radiused platen is almost like using a flat platen. It just does the grind with a small curve.
If you can flat grind a fairly straight edge bevel, you can use a 48" radius platen the same. At that size curvature, the edge will be only minimally weakened, an slightly sharper.
 
Thanks Brian and Stacy. I think rather than run the risk of messing this on up I will just grind it down to < .010" and see how it goes. I will post photos here when it is done.
 
I appreciate all the input everyone I just wanted to quickly update this. I decided to stick with the flat grind and not do a Hollow...

Here is what it came out like, I still wish more of the 1095 was exposed but lesson learned.
eDCF_0939.jpg
 
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