Todays oopsie daisy- learning hollow grinds

[Vance C.]

Until now, my main grind has been flat, but I have been drooling over Loveless and Bartlow knives, so I decided to try some tapered tangs and hollow grinds myself. Tapered tangs for me were fairly straight forward, and I feel pretty comfortable with them, but no such luck with hollow grinds. I wanted to do a full grind to the spine, but i am 90% sure my wheel is too small (using an 8" wheel, grind with 1" on .160" thick stock) because... i ground through my knife! This also shows that my grind isnt at the right angle, since the thinnest point is not the edge, so I'm going to have to play with my set up a little more. Any other suggestions or comments to help improve my next attempt would be greatly appreciated!

 

[J. ROSA]

I've done that a few times. It's not fun. If you haven't used it I'd recommend the grind height calculator. http://bimjo.com/free/widget.html
If you're grinding a blade and find you may exceed your projected grind height you can continue pushing the grind line up but will have to "feather" the bottom part of the grind or risk grinding through the blade. By feather I mean don't try to have the grind on the blade perfectly fit the contour of the wheel. Instead motion the blade up and down with light pressure as you make your passes to blend the grind in without grinding through the blade. Hope that helps.

 

[Ausbrooks]

Bummer Vance- chock it up to a good learning though. Rosa is right- it's good to know your perfect height using the calculator but can stretch the line if careful.
A little undercutting is ok as long as don't get the center too thin. Only other solutions are bigger grinding wheels or narrower blades. Was a nice looking grind till that happened though.

 

[C Craft]

Had to take a look when I saw the tittle because oopsie daises are right up my alley and when I can look at someone else's then maybe I won't make the same one! LOL I agree with J Rosa you either are going to have to blend or work with a larger radius. One thing that would help is too not take it all the way through to the spine with that particular radius!!

 

[Vance C.]

Thanks for the info guys! I think next try will be having the bevel just past mid point on the knife, and doing a false edge on the back, like this, but less amazing

 

[jmforge]

Razor guys consider an 8 inch grind on 1 x 1/4 inch piece of steel to be a "thick" hollow grind. You might want to use thicker stock for the 8 inch wheel. Don't worry because I think that you are in good company. Someone told me that what sets Loveless knives apart from some copies are the DEEP hollow grinds and Mr Loveless was alleged to have ground through a few blades in his time. :biggrin: