Collet wear and bit slippage

[jTr]

Had a dovetail bit slip for the first time ever. Utilizing Gary C's jig and part file for years - hundreds of drawers, no slippage.
In this instance, I had niether extra bits nor collets on hand. As I was 2/3 of the way through the batch, something needed to be done so I could finish. I pulled things apart and saw the score marks left on the bit's 1/2" shank and inside the collet - what to do?

As a last-ditch effort, I used a green scotch brite pad to alleviate the marks on the bit's shank by spinning the bit with one hand while holding abrasive pad stationary on the shank, and
(cringe here)
rolled up a 120 grit micro-mesh sanding disk, and spun in same rotating fashion to score inside the collet. Indeed, it held firmly for remainder of the job, and the friction was certainly noticeable as I loosened to remove the bit when done.

So... question is, would this be an acceptable practice for more taxing procedures, such as milling dovetails in hard maple, or am I tempting fate for an altogether worse issue with prolonged use (like a bit stuck in collet)?

Mechanically speaking, makes sense to score the surfaces in this fashion, as the abraded grooves interlocked, avoiding bit from slipping down and out again. However, logic insists there's a very good reason all this tooling comes highly polished...

Seeking enlightenment

Jeff

[dlcw]

I bought a brand new set of collets for my machine a few months back. All the collets held bits well, except the 1/4". I tighened a bit to the same point I always do and during the course of cutting, the bit slipped and went almost all the way thru the spoil board. I was really PISSED considering it was brand new. I went back to my old collet and it has been fine. I purchased the collets from a reputable supplier I've used over the years.

[gundog]

Make sure not to bottom out the bit in the collet before tightening if you do as the collet tightens the threads pull into the collet if the bit is bottomed it will not get tight as it is trying to slip the shank as it pulls in. I always bottom out the bit then pull it back out a little to keep this from being a problem. This may not be your problem but I wanted to share that with you.

Mike

[Brady Watson]

Once a bit spins in the collet it is burnished and is unfortunately trash. It should never be used again.

-B

[curtiss]

I would first assume these are not collets for a PC router.

With that said, for a PC router, the collets are not expensive, and I look at the bit and collet as one unit.

I seldom take a bit out of a collet, and have found a few drops of medium strength loc-tight on the bit shaft makes the bit "more slip proof" ... no actual science to back that up but ...