I use back bevels, second bevels or high angels on my hand planes,according to the different purposes, for years with great succes. After working with a lot off cherry and maple lately I wonder how usefull these “tricks” would be on a jointer or planer blade. Since I only have one set off blades for my machines at the moment, I’d rather ask around before making the effort off resharpening my blades.
Replies
borre,
I don't have a jointer, but I do have a planer and I always hone a back bevel on the blades. This has not hampered their performance on "regular" lumber and has been beneficial on figured lumber. I have not experimented with secondary bevels, or high angles.
Rob Millard
http://www.americanfederalperiod.com
borre,
I could be wrong, but as I understand it you can't back bevel them very much (1/64th) as it could lead to the back bevel healing against the surface and end up burnishing it, something you don't want.
I'm talking about back beveling on the back of the cutters here.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 7/27/2007 7:25 am ET by KiddervilleAcres
I have been having my sharpening service put a back bevel on my planer blades for years. Planing curly maple comes out as smooth as glass. I did try it on my jointer with similar results.
Lee
I have not tried it but I was going to have it done the next time I get my jointer knives sharpend.
I know that David Marks does this with good results and it is also recommended by David Charlesworth. Mr. Charlesworth actually shows how he does it in one of his books. I believe he just uses a small oil stone, a piece of paper to protect the infeed table, and does it by hand with the knives set in the jointer.
Borre,
Generally speaking the effectiveness of this dodge depends upon the existing cutting angle in your cutter block and the type of woods you use.Hardwoods definitely benefit from cutting angles from about 8 degrees to around 20 degrees-and you can achieve that by use of the back bevel grind. Softwoods plane better when the knives have a higher effective cutting angle- something of the order of at least 30 degrees, even up to 40 degrees.
You need to look at your cutter block and measure the cutting angle the knives are at, then you can decide how much to back bevel grind.
I use a back bevel grind on my thicknesser (Planer) , but prefer not to have this on the jointer because more effort is required to push wide boards and more downward pressure is required. Plus there is more noise.
If you have a heavy planer then it will tolerate very low cutting angles , even negative angles, which require more power as well.
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