# What Do You Do With Worn Flush Trim Bits



## JIMMIEM (Apr 4, 2010)

When a flush trim bit needs to be sharpened I have read that it will no longer work as a flush trim bit due to some of the edge being removed. Do you just use as a straight bit?


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## Quillman (Aug 16, 2010)

Flush trim bits are rarely flush to begin with.
If they are, they might cut the template!
It doesn't hurt to get a re-grind and if there's enough carbide, it can be done several times.
Notwithstanding, the regrind is never as good as the OEM grind.
As a rule, only the face of the flute is touched. The OEM hit, maybe hit 4-6 other surfaces the re-grinder would never do that.
So in my case, once they're dead, I scrap them.
Cutters are so cheap these days, it doesn't pay to have them sharpened!
And, yes, there is less diameter, but not much.


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## Nickp (Dec 4, 2012)

The diameter of the bit will be reduced by the amount necessary to re-sharpen the cutters.

If they just need a quick touchup (like with the Trend sharpening stuff) it might not change much (thousands)...but if you have nicks or such, chuck 'em...

In case you are not already, make sure you clean your bits with Trend or CMT bit and tool cleaner after each use...will make for longer, happier life...


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## Cherryville Chuck (Sep 28, 2010)

Professional regrinders have other sized bearings to replace the original with that are a few thou smaller and will compensate for the reduced diameter. I've seen somewhere where they were available for retail sale but I can't remember where. Like Pat said though, they are hardly worth it at the difference in cost. I have heard of professional woodworking shops that will save up a batch of worn bits and then send them out and by having a volume of them done it is cost effective.


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## scottgrove (Sep 4, 2016)

I like to use them as a preliminary cut bit. This removes most of the material, then when you hit it with a new bit, they stay sharper longer and just kisses the material for a finer cut. this really work for Plastic laminate.
I have also ground off the threaded nub on the bottom and just use it as a straight cutter.
Enjoy!


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## JIMMIEM (Apr 4, 2010)

scottgrove said:


> I like to use them as a preliminary cut bit. This removes most of the material, then when you hit it with a new bit, they stay sharper longer and just kisses the material for a finer cut. this really work for Plastic laminate.
> I have also ground off the threaded nub on the bottom and just use it as a straight cutter.
> Enjoy!


Good idea for plastic laminate....I'm about to start making some plastic laminate countertops.


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## scottgrove (Sep 4, 2016)

I will also add an extra large bearing so I can cut off the excess without risk of kissing the surface. Then I go back with the bevel cutter.


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## fire65 (Oct 29, 2008)

JIMMIEM said:


> Good idea for plastic laminate....I'm about to start making some plastic laminate countertops.


 Try a solid carbide laminate bit, no bearing, once you use these I doubt you will ever use the flush bit again. No bearing and they cut much cleaner with no chance of hitting the front edge. I used the bearing style for years, until I got some of these.


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## Cherryville Chuck (Sep 28, 2010)

Clay you don't have any issues with the pilot burning the edge? That was the problem with the old HSS router bits with pilot.


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## fire65 (Oct 29, 2008)

Cherryville Chuck said:


> Clay you don't have any issues with the pilot burning the edge? That was the problem with the old HSS router bits with pilot.


 NO, I never use HSS bits, these are carbide. I run vaseline down the front edge and the bit cuts fast and clean. I have laid a lot of laminate in my years, wish I had known this years ago. Plus they are cheaper.


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## CharleyL (Feb 28, 2009)

I agree with Clay (Fire65). I learned the Vaseline trick many years ago. I now use it every time a bearing or non bearing bit will be run against laminate to guard against burning of the laminate. You don't need much, just a thin layer, so it cleans off easily after the cut. I have a 1/2" paint brush through a drilled hole in the cap of my large Vaseline bottle that gets used for application. 

Charley


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## paduke (Mar 28, 2010)

Just read this in an article on scrapers. Take your dull carbide spiral bit insert it cutting end first into a handle and you have made a wonderful burnisher for sharpening your scraper blades


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## JIMMIEM (Apr 4, 2010)

fire65 said:


> Try a solid carbide laminate bit, no bearing, once you use these I doubt you will ever use the flush bit again. No bearing and they cut much cleaner with no chance of hitting the front edge. I used the bearing style for years, until I got some of these.


Thank You,
I'll give 'em a try. I buy most of my bits from Infinity. Whose bits do you use?


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## scottgrove (Sep 4, 2016)

can you explain more on what this bit looks like? does the bit run on itself with no burning?


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## fire65 (Oct 29, 2008)

I use many different brands of bits, CMT, freud, whiteside. This is a link to a solid carbide, I am not suggesting this bit I just did a quick search, but these will do it and for 10 bucks. Laminate Trim - Solid Carbide Trim Bits

I apply the laminate edging, trim it all flush, clean everything then mask the top of the edging with blue tape. Glue the top then remove the tape to remove any glue the drips down from gluing the top. Apply a thin coat of vaseline, set the bit height and cut.


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## Oddyseas (Nov 25, 2021)

JIMMIEM said:


> When a flush trim bit needs to be sharpened I have read that it will no longer work as a flush trim bit due to some of the edge being removed. Do you just use as a straight bit?


The blades are supposed to be at the exact same diameter with those bearings, if the blade gets sharpened, even if u send it to a professional service, the diameter is gonna get reduced. Don't get those cheap HSS bits, get solid carbide ones that last longer here's where I get flush trim bits from. Cheers!


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## jw2170 (Jan 24, 2008)

Welcome to the forum @Oddyseas


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## old55 (Aug 11, 2013)

Welcome to the forum @Oddyseas


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