Hi,
The recent article by Joel Moskowitz, “Grind Perfect Edges Without Burning” http://www.taunton.com/finewoodworking/FWNPDF/011198062.pdf
has made an immediate and vast improvement in the speed and quality of my plane iron sharpening. His suggestion to bevel the face when dressing the wheel seems anti-intuitive and too simple by far, but it works like a charm.
I recommend it to all us newbies to hand planes.
Mike D
Replies
I have never been able to master hollow grinding on a wheel. But I saw the article, and I'm sure it's effective if you can get that first hollow ground right.
Denny
Me too. I have almost always burned at least one corner during grinding and had to grind back to eliminate the burn and start over. No such problem using the beveled wheel.
I used his idea to match the angle by setting the angle by eye to the existing bevel with the middle of the bevel against the stationary wheel, and then rubbing the blade across the stationary wheel to verify that you actually have the middle.
In an other article, it was suggested that we make cardboard angle templates out of 4"x4" card stock, with the thickness of the blade to be sharpened marked along the bottom edge. I've made ones at 20, 25, 30, and 35 degrees using a protractor and scissors, and that seems to work well in setting the initial angle of the rest.
Mike D
Edited 6/9/2008 5:49 pm ET by Mike_D
Hollow grinding is very easy--if you unplug your grinder!! I read one of Krenov's books about 20 years ago and saw the wisdom in his little homemade, hand-grinder rig. I built one, bought the hand grinder and have been happily hollow grinding ever since. Going slowly really takes the stress out of it!! LOL
Regards,
Mack"WISH IN ONE HAND, S--T IN THE OTHER AND SEE WHICH FILLS UP FIRST"
Oh, I certainly agree! My Dad, uncles, both grandfathers had hand driven - actually crank driven - bench grinders for sharpening. I haven't seen one of them in years! Takes me back, though.
Mike D
Mack, I've never had a setup whereby I could put a consistent angle on with a grinder. I make out okay with the Veritas flat grinding machine.
Denny
I've never had a setup whereby I could put a consistent angle on with a grinder. I make out okay with the Veritas flat grinding machine.
Denny
You can hollow grind a specific angle (using a high speed grinder of any size) if you use the angle setter that comes with the Tormek. That's what I do.
Regards from Perth
Derek
I retired my Tormek. I'll see if I have the angle setter.
Denny
You don't need to set the angle of the tool rest at all. Simply slide the chisel or plane iron up onto the wheel until the bevel angle aligns with the face of the wheel. Let the handle or top of the iron rest against the tool rest edge. Wrap your index finger around the tool with it just below the tool rest so that you can maintain that position while moving back and forth. Keep that grip throughout the process. You will find that this is very fast, very accurate, and very consistent. The action is not unlike one employs during the honing process.
You don't need to set the angle of the tool rest at all.
Perfect accuracy of angle is unnecessary with BD plane blades and chisels. Getting into the ball park is all that is needed.
Regards from Perth
Derek
Denny,
After reading the FWW article, I made a user-friendly tool perch on my grinder at the correct angle. Before taking a chisel to the wheel, I decided to "practice / experiment" with some abandoned spade bits and worn Apex driver bits just to get the hang of it. I have yet to sharpen any chisels or plane irons, but now have a nice set of screwdrivers, a new marking knife, and several awls and punches.
When the time comes to grind on a chisel, I think that the effort spent becoming familiar with the grinder will pay off. Give it a shot.
Best!
-Jerry
I guess I never figured out how to make that "user friendly tool perch".
Denny
There is a thread over at Sawmill Creek on the FWW article. Nothing about "perches" but some feedback on hollow grinding none-the-less.
http://www.sawmillcreek.org/showthread.php?p=869206
Best!
-Jerry
I would say this method is all well and good for most western chisels and planes. It is a very efficient way of keeping your blades toned up but it can not be used universally. IMHO
The Japanese chisel is not meant to be hollow ground - ever. That is unless it's disposable. Most Japanese chisels are a little too expensive to treat them like a Marples - and Marples are fine chisels for their purpose. Hollow grinding a laminated eastern blade eats into the hard metal without compensating for the bottom hollow. The bottom hollow must be maintained in order not to loose all hard metal at the cutting edge. This, contrary to old wives tales is not maintained by "tapping out the hollow". This is occasionally true for Japanese plane blades but never true for chisels. The flat bottom is re-flattened at the same time that the bevel is re honed. If sharpened properly, the hollow will retreat proportional to the edge sharpening. With out working the bottom, the hollow grinding will, in short order destroy the hard metal cutting edge. The only way to save the chisel then is too massively grind a new flat on the back and finish back to a mirror edge. Hollow grinding also reduces the cutting edge ( as does micro bevels) to a extremely fragile thin edge on a very hard steel. The result is like dropping crystal onto concrete. Japanese hard steel doesn't give way like western steel and these chisels need more shoulder which the hollow grind removes. As to the micro bevel, which we all like, it was designed into the eastern blades with the original bevel so as to cut in a way that they were meant to, on what they were meant to, rather than for the connivence of the user for quicker, faster, sharpening, cutting. They are a different beast.
I use hollow grind and micros on most of my blades but never on an eastern laminated blade.
See William Young's FWW 115
http://www.taunton.com/finewoodworking/ToolGuide/ToolGuidePDF.aspx?id=2378
Regards
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