New project and question - anyone who grinds recurve want to give advice?

ERIK KNIVES

ERIK KNIVES

Joined
Aug 17, 2010
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I'm working on a rescue boat knife project. These are templates. I have subject matter experts advising me on the overall design, but the hawk bill/heavy re-curve version in not something I have ground before
(and will be one of one or two). I'm good on the other knife. I normally flat grind but would hollow grind that re-curve if there is a need. I know how I would approach it if I were doing it today, but I may wrong. Any suggestions on how to tackle the grind on the re-curve would be appreciated.

The drawing is not mine, it is from an operator. It is a trace of my paint-stick mock up, with suggestions. I have at least one better idea, so ignore the drawing for the most part, especially the pins and the American-style Tanto.

The hole in the drawing below the spine is for a shackle key.


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I'm hoping this may help some, Erik. Go to 1" wide belts and as always try to keep the grind at the edge as consistant as possible in thickness . Frank
 
I was afraid of that, Frank, I've never ground with 1" belts. Do you have a splitter for 2"X72" belts or do split them by hand?
 
You can also use the edge of the platen. Actually the same thing as Frank said but grinding with an even smaller belt if you want, making contact with maybe 1/8th of the belt if even that. Makes sense? Hard thing is keeping things even, edge thickness, curve of the grind, etc, because you have less surface contact to stabilize the knife. But if you get the hang of it, it will let you do almost any radius recurve.
Hope this makes sense.
 
Makes total sense, Patrice. Thank you Frank and Patrice! Not to mention your great advice, you gave me an idea that I may try in the future. Thank you. Erik
 
Do yourself a big favor and order some 1X72" scalloped edge grinding belts. The trizac A100 is a great one for setting the grind.
The scalloped edges don't leave gouged lines cut in the bevels.
 
Also, a big coarse file is your friend for evening out your edge thickness and putting your grind line right where you want it. I tend to use the edge of the belt to rough in the grind then finish it with files.
 
I find that holding the blade parallel against the contact wheel works very well for grinding concave-edge bevels. It will leave a very gradual plunge; if you want the plunge to have a tighter radius, you'll need to work on it with the edge of your flat platen or a round file.

If you're like me and don't quite get 'em perfect on the contact wheel, draw-filing will even them out pretty quickly.
 
I use the method Patrice mentioned - using the edge of the wheel or platen. I usually hang the belt a good 1/4" or even 1/3" off the edge. Thanks for the scalloped belt suggestion, Stacy. I'll definitely being trying them out.
 
Thank you all! Great suggestions and I appreciate each of you sharing your experience. This is just what I was hoping for.

EA
 
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