sharpening planer/jointer knives

[tmbg]

Could someone give me a rundown on the proper way to regrind planer knives on a tool grinder? We have one of those makita sharpener dealies, and it has a tool rest with a fixture to clamp planer knives in, but I'm not well versed in the method, and I'm afraid of burning up the knives. I don't much want to do it by hand, because the knives are full of 1/32" nicks. Don't worry, the knucklehead that ran the boards full of nails through it is banned from the shop

planer btw is a grizzly 15", stationary cutterhead type, 3 knives I believe

[Scott Post]

Go to Highland Hardware's site:

halfway down the page click on the "More Information" link for their own write-up on how to use it to sharpen jointer/planer knives.

I use the Makita to touch up my 12" planer knives and 8" jointer knives but I wouldn't mess with trying to grind out large nicks on this machine. I'd send them out. The reason I do touch ups is because nobody local to me does a good enough job and it's not cost effective to do it mail order. However, I wouldn't trust myself to get them straight and parallel when doing heavy grinding - I'd bite the bullet and pay someone.

[George]

Follow the directions that came with the Makita. That's what I did, and they've worked for many years of mine and others' knives.

Only thing I would recommend in addition is to make an angle jig for setting the fixture say 165 degrees for most knives, and to recheck the support screws behind the blade, snugging before you release the sharpened one. Makes the second and third easier.

The water will keep you from burning the blades, but progress will be slow if you have only the fine stone. For the much-abused planer at school (also a 15" Grizzly), I take a couple passes with the 60 or 80 grit green stone they offer, then go to the fine.

still active, and good for other things.

[tmbg]

I'm sorry, the one we actually have isnt the makita, it's a grizzly. It's similar to the makita, but it doesnt have the water reservoir. Also, it's old and the stone needs dressing I think.

Can I get away with just dripp> Follow the directions that came with the Makita. That's what I did, and

[George]

Now I don't know what your machine looks like, so can only speculate that a stone made to be used wet would have a reservoir, a stone without is probably designed for dry.

If this, looks like dry is it.

similarity between it and the Makita appears to be the knife holder.

Oh yes, fumblefingers meant to type 145 degrees, not 165, though that gives

30 degrees, some are 35.

[tmbg]

Hey! that's the one!

I spent a good while on their site and couldn't find it :P

thanks a bundle :)

[Jim Wilson]

If your knives are high speed steel (many are, but some are not), you won't ruin the temper as long as you keep them cooler than red hot.

Jim