Planer knives

1. Get a board at least 1/2” thicker than the width of your planer blades and about 5” wide and 6” longer than your plane blades. MDF works well for this.
2. Cut two lengthwise parallel grooves in the board from end to end with the same angle as your planer blades and also the same width as the thickness of your planer blades to a depth a little less than the width of you planer blades. the grooves have to be pointed from bottom to top towards the opposite edge of the board and an inch or two apart.
3. Insert the knives in the grooves and the bevels should be slightly protruding from the top the grooves. The knives should be placed so that there is 3” left on each end of the board to use for clamping it to your bench.
4. Check to insure that the bevels are the same height or very close to it.
5. You need a sharpening stone or MDF with different sandpaper grits glued on and nice with a piece of wood glued on the opposite sides of the MDf to use as a handle. I use my DMT 600/1200 grit diamond sharpening plate for this purpose.

Please don’t hesitate to ask if you need clarification on any of the above explanations.

-- Mike, an American living in Norway.

Just send them out.
Planer knives are only a ccouple times a year.

15 inch knives are 8 bucks to sharpen. If you value your own time at all, you are spending more than 8 dollars messing with jigs and such.

http://planerknivesdirect.com/sharpening.php
aka Connecticut Tool and Saw

-- “The two most important days in your life are the day you are born and the day you find out why.” Mark Twain

I send mine out also.. not worth the hassle for the results I get trying to do it myself. My local shop does a spectacular job and always returns them in perfect shape and better than new. Although around here, they charge $1 an inch!

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

I guess it depends on the planer. For most of the bench top models, like the popular Dewalt DW735, new knives are as cheap or cheaper than sharpening. I assume you are talking about a more substantial machine.

I’ve noticed more than once that when I send blades out to a “Professional Sharpener” (via. a local hardware store) they came back wavy. When you get them back, put them against a window that looks outside (like you would use a light table). Put them sharpened edge to sharpened edge. Check them against each other you’ll see what I mean. I sharpened them better myself with my Grizzly G2790 Universal Knife Grinder. Anyway, I resolved my planer knife sharpening problems and bought a Spiral Cutterhead for my 15” Planer.

Lotsa good info above.

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed. [email protected]

I’ve had then sharpened with varying results. If you have to grind out Knicks, send em off. Just touching it up? Make a jig.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

I have sharpened my “disposable” knives with 1000 grit sandpaper and a tiny bit of water on my table saw top (cleaned immediately afterwards to prevent rust). With just a couple of strokes on each knife, it was cutting better than new. I just laid it on the bevel, counted 5 or 6 strokes along the length of the knife, a couple strokes on the back, and done. Yes, you get great results sending them out, but my 20 minutes and single sheet of 1000 grit paper served me just fine if you only have one pair of knives or aren’t in the world’s greatest hurry.

-- Brian T. - Exact science is not an exact science

Here is my method.

-- Scott Smith, Southern Illinois

Thanks to everyone for the great ideas! I made a jig with 45 degree kerfs cut lengthwise. Then I put sandpaper, grit side up, on my tablesaw top and put the jig, knife side down, on the paper and moved it back and forth about 1000 times, on sandpaper up to 220 grit. Now I can see scratches on the knives. I’m assuming that I need to get finer paper to remove the scratches.

-- Glen

I usually stop at 400 grit.

-- Scott Smith, Southern Illinois

I agree with DrDirt.

I just buy new ones.

-- Everything is a prototype thats why its one of a kind!!

http://lumberjocks.com/projects/106720
This is the jig I use to hone my blades after they are reground.
Guess as long as there are no nicks you could re-sharpen many times ?

-- Lifting one end of the plank.

on pinterest there are a number of jig for the pourpose.
this is one but other can work as well.

-- the good woodworker feels what the tree wanted to become