Why does sharpening seem harder than it sounds (rhetorical question).
How flat is flat enough when lapping the back of a plane blade or chisel? I have been trying to flatten the back of a plane blade or two and cannot seem to get the very last little bit flat. I have been using a coarse diamond stone. Is it simply a question of needing to use something more coarse first, then moving to the diamond stone (then of course something finer – a waterstone in my case)? Attached is a picture, with the very edge marked to see where I am at.
bc
Replies
Just me.. I never tried to get my tools really, really flat.. I think I did like you..
I got all mine flat over time. When I had to sharpen the blade I would do the plane or back of the chisel also.. I guess all I am saying is not to worry if you did the best your can.. Over time it gets easier..
Others Opinions..
Liz,
Looking at the back of the iron, you need to have a polish over the cutting edge, but it needs to be flat the whole width of the plane iron. You only need to flatten the last 3/8" (as the chipbreaker/backing iron sits on this flat, nothing else contacts the rest of the blade)
Try flattening only the last 3/8" of the plane blade - it'll go faster.
Chisels are a different story - flatten back 2" from the cutting edge.
Cheers,
eddie
"Try flattening only the last 3/8" of the plane blade - it'll go faster."This of course makes sense to me. However, how do I keep only 3/8" of the plane blade on the stone and work it while keeping it perfectly flat, .i.e, not rocking all around.bc
bc,a fair bit of downward pressure - costs nothing to give it a go.Cheers,eddie
I place a very stong magnet on the chisel when I'm honing the back. The magnet acts like a "handle" and it sure makes the process easier on your fingers.
Power belt sanding the chisel back will help as a first stage if the chisel is really hollowed out. Use aluminum oxide belt. After diamond stone use various graduated grits of silicon carbide paper glued to something dead flat.
The blade looks bad - wonder how it got in that shape is it bent or been on a Grinder ? How about a new Blade?
"The blade looks bad - wonder how it got in that shape is it bent or been on a Grinder ? How about a new Blade?"You are jogging my memory a bit. It has never touched a grinder or been dropped or bent. The first time that I flattened the blade I was a complete newbie and may have done it on a waterstone that needed flattening. I actually do have a brand new spare blade for that plane, however, I would like to rescue the "bad" one if I can.
lizurd,
Unless you have a belt sander with a PERFECTLY flat bed to flatten this plane iron, you will spend HOURS in more frustration and poor results. And that really takes the motivation out of this craft.
Start with a new blade, you'll be glad you did. Send the old one out for professional grinding/flattening if you wish.
Rich
Either your stone isn't flat or you've got a really, really lousy blade there, with a big "belly" in the middle.
I'm editing this to suggest that you'll spend a few more hours trying to get rid of that "belly" on a stone. Time for some mechanical device like a belt sander!
Edited 1/21/2005 5:06 pm ET by MARKRODERICK
My experience is that only Lie-Nielsen blades (pretty much) come surface ground (maybe Hocks as well???), so I either replace my plane irons with a Lie-Nielsen, or if I want to use the original (with all of those horrible course grinder marks!!!) I will take my little Dremel -- loaded with a grinding stone, or polishing wheel -- and create a very shallow cavity on the back of the blade that comes within,say, 1/8th" or 3/16th" of the cutting edge and sides ... you know- kind of like what Japanese plane irons and chisels have. It makes putting a mirror finish on the back (which is essential for a truly optimized cutting edge) a *relatively* quick job.
Yes, it does make the blade's life somewhat shorter, but the time saved is CLEARLY worth it considering the relatively low cost of the non-premium blades (I even do this to some of my chisels as well). Unless one nicks a blade, one doesn't generally remove much steel come sharpening time ... so depending on how much you use, or sharpen, this-or-that chisel/plane blade, it may still last you the rest of your life?!
I'd be curious as to whether or not other people do this ....
Peter T.
Hello Lizurd. This has got to be the perfect time to once again bring up David Charlesworth's ruler trick. Maybe you have never heard of him but he is a well renowned English cabinet maker with a passion for the tuning of hand tools. Sharpen the front side as you normally would . Take your finest stone, I think you mentioned having a waterstone, and lay a 6" long ruler along one long side. Lay your blade on top of the ruler and take short 3/8" strokes to form a bevel on the back side of mirror polish. This is only a rough explanation of coarse but you should go to the Lie-Nielsen website and purchase Rob Cosmans sharpening video and learn how to sharpen in the least amount of time with the greatest of results. Anyone that watches the video could sharpen that blade using only waterstones in about 1 minute, no exageration whatsoever. The blade would be sharp enough to cut hair on your arm without touching the skin. Good luck .
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