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Discussion Starter · #1 ·
I should know this but I'm not sure. If you have a carbide router bit that is starting to get dull, and if you have a diamond wheel, do you grind on the front flat side or the angle part after the cutting edge?

I don't want to grind a lot, just touch it up.
 

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Tuff question;
 

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Discussion Starter · #3 ·
If I grind the back side I will change the profile if I'm not careful. If you grind the front flat part, the profile won't change.
 

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Woodworking Wanderer
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I was taught to use an (expensive) diamond stone on flat side. Count the strokes on each edge and repeat, so they are all the same as each other when you're done.
 

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If you grind either side the profile could change, as I understand it. It's because the two sides of the cutter are not 90 degrees perpendicular to each other. Any removal of material from either side will move the cutting edge back inward from where it was originally. I'm thinking in terms of a straight bit mostly, but I believe most all bits are this way.
 

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Don't grind anything! Draw the flats (only the flats) along a thin diamond hone paddle. Most woodworking stores sell a 3 pack of green, red & blue paddles. If you draw the flat sides (always both sides) 5 times with each grit, you should be able to feel the sharpness with your thumbnail. Credit card sizes are also available, but the middle part never gets used. Clean up is water.
 

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Leonard Lee (Lee Valley) The Complete Guide To Sharpening. p 211-213.
Never touch the bevel. Lap the flat faces. He's forgotten more about
edge management than I will ever learn.
 

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Old Methane Gas Cloud
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Blasphemy

Router bits are almost like saw blades, expendable. While saw blades can be sharpened a couple of times router bits can be sharpened either zero or many times.

The difference of sharpening router bits zero or many times depends upon your definition of the expected results.

Examples of sharpening many times:
A 1/2" straight bit that is used primarily to cut dadoes for 3/4" ply wood or melamine. The cut requires two passes and the objective of the second pass or cut is an exact fit.

A round over, cove or beading bit can be sharpened many times. When used in a router table the fence controls the depth of cut and there is no need for a precise cut. Do you care that your 1/4" round over bit has an actual radius of 0.258"? (33/128")

Any chamfer, flute, core box or molding type of bit can be sharpened several times without much consequence. It's all about the shape of the final cut. If you're trying to match existing molding with a newly cut piece, proceed with caution.

Examples of when to not sharpen router bits are:
Any rail and stile combination bit set. The more the bit set is sharpened the poorer the joints will fit.

A sharpened flush trim bit could be a disaster if used on high pressure laminate. The bit would cut flush and make for a lot of file work.

Many bits (Quadra is a brand that comes to mind.) are designed with a spiral cutter face. Your little flat diamond hone will not evenly sharpen the entire surface.

What is the solution?
First clean the bit. Any of the organic blade cleaners will work well. Mineral spirits and an old tooth brush will work too.

After cleaning you can try the bit or go directly to touch up with the diamond hone. And how many times do you really want to try the touch up process with the hone. That is your decision.

One further thought about sharpening. The cost of sharpening a router bit is $8 to $10 for the simple profiles. Does it make financial sense to YOU to sharpen a bit that can be purchased new for about $20?
 

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If the bit really is banged up and TC besides, buy another.
Then you can fool with the dead one.

I don't do enough router work to justify any tune-ups.
All I've learned is that my router ain't a freehand carving tool like a Dremel.
 

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where's my table saw?
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don't grind anything

I should know this but I'm not sure. If you have a carbide router bit that is starting to get dull, and if you have a diamond wheel, do you grind on the front flat side or the angle part after the cutting edge?

I don't want to grind a lot, just touch it up.
Don't grind anything! Draw the flats (only the flats) along a thin diamond hone paddle. Most woodworking stores sell a 3 pack of green, red & blue paddles. If you draw the flat sides (always both sides) 5 times with each grit, you should be able to feel the sharpness with your thumbnail. Credit card sizes are also available, but the middle part never gets used. Clean up is water.
You can "refresh" the cutting edge by sliding it along a diamond hone as suggested. Typically even new bit can use a bit of careful honing on the flat, not the beveled edge. I do this on a regular basis with good results.

Check in at 6:02 for the method:


another version;
 

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Old School
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You can "refresh" the cutting edge by sliding it along a diamond hone as suggested. Typically even new bit can use a bit of careful honing on the flat, not the beveled edge. I do this on a regular basis with good results.
You can do whatever you want...they are your bits.:yes: If your "new bits" need some honing, I suggest you buy a better brand.:yes:






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where's my table saw?
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what's a "better" brand?

Better than, Whiteside, Stone Mountain, Freud, CMT, Bosch, Infinity?
 

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where's my table saw?
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they don't "need" honing...

So, you buy all those brands and they all need honing when new... that's incredible. Try Amana.






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:no: need is your word
 

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Old School
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:no: need is your word
Your words... "Typically even new bit can use a bit of careful honing on the flat, not the beveled edge."

If they can use honing, that sounds like they NEED it, otherwise why would you do it. If they don't NEED honing is this just a semantics game for you?:laughing:






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where's my table saw?
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Yep

No matter how helpful I am, posting links, videos, and my own personal experience, you find some way to hijack the thread and make it about me, personally. That is boring, trival, rude and and not helpful to the original poster who started the thread..... so why don't you go out on your 1960's well equipped shop and build something and post a picture of it in your album that is later than 2007? That would be really helpful. :no:
 
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