I have a question on lapping plane blades. When I lap my chisels I get the metal really shinny and that is how I tell it is complete. I have a new Lee valley low angle block plane with an A2 blade. I spent a fair amount of time last night lapping the blade but could not get it shinny. It seems to stay a dull uniform gray. Do I need to get the back of the blade shinny….I am using a water stone system up to 8000.
thanks
Replies
I'm probably not the best person to ask on this subject. I think that way too much time, and magazine space, is being spent on sharpening woodworking tools.
I sharpen my planes until they're sharp enough to do what I'm trying to accomplish and I sharpen them again when they start to have trouble cutting. I use an antique hand cranked grinder, with a 5" wheel, and a simple shop made blade holding jig to get the basic angle on the blade.
After grinding, I use a DMT two sided hand held sharpening stone, it looks like a file when the handles of the stone are folded open, to do the final sharpening. I hold the blade in my left hand and the diamond stone in my right hand, and keep my elbows against my ribs for stability. The bevel will have a hollow grind and it is fairly easy to feel when the ground surface is flat against the stone. I can resharpen the blade several times with the diamond stone before the hollow gets ground away and then It's back to the grinder.
The grades of the two sides are something like fine and extra fine, they're color coded red and green by DMT. I clean up the ground edge with the fine stone for maybe a minute and then spend another 30 seconds with the extra fine side to further refine the edge. I'll take a few flat passes on the back of the blade with the extra fine side at the end to clean off any burrs.
I generally don't look at the blade, I just run my thumb over the edge and quit when it feels sharp. I could do this in the dark if I had to. I honestly couldn't tell you if my blades are shiny when I'm done.
The final sharpening could be done with something other than a diamond stone, I just like the speed and simplicity of them, they require no lubricants and no maintenance other than an occasional scrub with a tooth brush, and they seem to last forever without going dull.
I'm hoping to stop in at Fine Woodworking in a month or so to shoot a video of how I sharpen tools, it will show up here eventually.
John White
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