Recommendation? Grinding Bevels on Wide and Thin Blades?

S

SLC_Blades

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Aug 20, 2018
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Hello everyone, I recently got a commission for something quite similar to a Chinese vegetable cleaver— wide blade (2.5”) and thin stock (94 thou.) and it’s really thrown me for a loop to say the least.

I’m at the point where I’m confident with my ability to freehand flat grind, but the extremely shallow angle that’s required to grind this bevel is incredibly difficult for me to maintain consistently. I’m considering learning to grind with a work rest because I feel that it’ll make this project a lot easier, but I don’t have experience with that.

Does anyone have any tips/techniques for achieving this? Thanks!
 
Good Morning, do you own a Bubble Jig? They are helpful in a grinding situation such as this.
I put a piece of electrical tape on the spine to keep from grinding into it.

Fred
 
Huh, I learned to grind with a tool rest, but would probably try to full-taper something like that without it. Do you use a magnet, or hold the tang?

Being wider than the belt it's tricky. Are you using a 2x72? A wider belt might help.
 
Try laying the blade flat on the platten of the grinder, either horizontally or vertically. Using your thumb or a push stick, apply pressure only to the edge you wish to remove stock from. Try this on a piece of scrap metal or wood untill you get the process worked out. You should be able to achieve a very flat even taper. Just realize the spot you are pressing on will get hot quickly so work your way down the edge as you grind, and cool frequently to prevent warping.
Jim A.
 
I do most of kitchen knives at that thickness and I have been asked for a couple "saber grind" type knives. Mostly I did them to see if I could. I failed miserably on a long slicer (ended up convexing the grind) but had a small camp knife work out well this weekend. It is very difficult given the shallow angle and any variance moves the line a lot. You need a brand new belt for the final couple passes. I also do use a work rest with a finger behind the blade to control the pressure. I find rests much easier for these but I'm still very new at this. On the final passes I slow the grinder right down to a crawl. I'll also put my finger directly behind the spots where I need to raise the line so I can vary pressure and use the edge of the belt for more precise control. For the most part, my finger stays still and I slide the blade between the belt and my finger.

A hollow grind would allow a bit steeper of an angle and may be easier but may get too thin. I've never done a hollow grind.

This grind wasn't very high so it was a bit easier.

View media item 6067
 
Use a work rest, rest your fist on it and use your index finger for the spine of the blade to ride upon and your thumb for pressure.

Pull the blade across your index finger and you can get some very smooth consistent grinds.
 
All the above.

I also suggest doing the grind after HT.

I start the grind with the knife horizontal at 220 grit and finish with it held vertical at 400 grit.Then I do a horizontal finish with a medium Scotch Brite belt.
 
Probably less of an issue with a wide cleaver shape, but when grinding thin stock like a paring knife on a work rest be VERY VERY careful to keep the spine out of the gap between the belt and work rest as the blade tapers toward the tip. Else it will get grabbed and shoved down between the belt and work rest. Careful setup and complete attention can moderate the risk somewhat. Very dramatic when it gets grabbed... *shudder*
 
A proper work rest should have a shallow cut out that fits around the wheel/platen at least 1/4". It will be impossible to get anything wedged between the wheel and the rest that way.

If you have a rest that isn't boxed like that, just put on a coarse belt, loosen the work rest arm a bit, and push the rest into the wheel/platen to grind a notch about 1/4" deep. Track the belt a tad left and repeat to trim it a tad wider, then track to the right a bit and repeat. This should notch the work rest son it will not allow a blade between the table and wheel/platen in normal grinding.
 
Earlier this year I was grinding on a bolster with a 36 grit belt wide open when the bolster slipped between the table and belt. My finger went right into the belt and the top of my finger tip and nail was gone in a flash. It's since grown back but feeling is a little funny. Good word of advice above.
daizee said:
Probably less of an issue with a wide cleaver shape, but when grinding thin stock like a paring knife on a work rest be VERY VERY careful to keep the spine out of the gap between the belt and work rest as the blade tapers toward the tip. Else it will get grabbed and shoved down between the belt and work rest. Careful setup and complete attention can moderate the risk somewhat. Very dramatic when it gets grabbed... *shudder*
Click to expand...
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