Touching Up Router Bits

I had responded to someone offline about how I touch up router bits. I thought I would share this here in case it could be helpful.

I made a little jig out of a block of wood to hold various round shafts in my vice. I use a set of E-Z Lap diamond “sticks” which seem to go on sale at Rockler on a regular basis. Even at full price, they’re reasonable. I've been using this set for years.

.

Just as in sharpening Forstners, you don’t touch the bevel edge unless you are doing repair of a chip or the like. On router bits, if I hit something and knock a corner off the carbide I have to do an assessment as to whether to sharpen or replace but, back to “touch ups”. Use the flat face of the cutter as registration surface. Give two or three swipes to each flute maintaining contact with the flat for guidance. I stroke away from the bevel edge as generally this is easier access-wise.

.

For edges that have gone too long (or been used on pecan, hickory, wenge and other cutter-eating woods) I may start with the course stick and give two swipes each through the grits. The key here is to do as little as possible. We are just touching up to rid ourselves of that fuzz or burning that can crop up in mid-project. If you find yourself having to do more than just a touch up, send the bits to be sharpened. My ability to remove significant material without setting the bit out of balance is questionable .

I actually have a set of those. Need to make one of your blocks for holding the bits. Thanks!

Thanks Glenn. I always wondered if those hones were even any good.

I think i would err on the side of replace but that would also depend on what quality of bit i had purchased to start with.

I do know what router lady says though.

Sent from my MB860 using Tapatalk 2

Yes, the Router Lady opts for replacement. But using Glenn's method will get you through a project - and then replace the bit.

If I were to make Glenn's jig, I would think about holding the bit horizontal to its shaft. I am more comfortable using the sharpening sticks in that configuration and think I could get more consistent results. As Glenn noted you can get the bit out of balance and at 10-23K RPM, that is an issue - for your router bearings. A much higher repair/replace job than most new bits. Just sayin...

Carol Reed said:

Yes, the Router Lady opts for replacement. But using Glenn's method will get you through a project - and then replace the bit.

If I were to make Glenn's jig, I would think about holding the bit horizontal to its shaft. I am more comfortable using the sharpening sticks in that configuration and think I could get more consistent results. As Glenn noted you can get the bit out of balance and at 10-23K RPM, that is an issue - for your router bearings. A much higher repair/replace job than most new bits. Just sayin...

Click to expand...

Very good point

I have a set of those hones and I bought them for just that purpose.

My problem was that I was trying to sharpen dull bits and that didn't work out that well.

A touch up before the dull stage seems like a great idea for those of us too poor to buy bits as often as we like

If one was going to touch up a bit more regularly then how often should it be done. for instance; say I make 6 doors with cabinet makers door set. could I then use a medium (skipping the course hone) and then fine hone with a few passes each? thus keeping the bits sharp but not removing too much material?

Or should i wait to see some burring and very slight burning before I do this?

Keith, I touch up if the bit is doing less than a stellar job or I feel the resistance higher than I would expect. Trying to restore a damaged profile is a job for a pro if the bit is worth it; or a replacement if it is not. If a bit has gone truly dull and is worth the cost, have it sharpened, you probably can't reliably remove that much material. An out of balance cutting tool spinning at 30,000 RPM could be disastrous. When I pick up inexpensive bits on sale or clearance, they usually get tossed. The exception is when I get a high quality bit on sale or clearance ;-)

When deciding to sharpen or not, the brand and where you can get service can have a lot to do with it. I have had places that say they sharpen to Freud's specs and then ruin the geometry of a cutter (and replace it). Whiteside sharpens their own and getting a $30 bit sharpened for $7 means I have now gotten two $30 bits for $37 dollars, or three $30 bits for $44. Now if I happened to get that $30 bit on sale for $18 . . . well, you get the picture. Its a judgement call. Doing multiple bits per shipment and USPS flat rate boxes help this make sense. Different methods will make sense for different folks depending on their work, location and so forth.

I have been doing the touch up for years with the same diamond sticks. No jig, just hand held. Be sure to totally clean the bit before doing anything - that is often enough to get the performance back.

I only do the flat side of the carbide, keeping the sharpening stick flat on the entire face, and make sure I take identical strokes on each carbide - e.g. two medium grit, three fine grit.