Hi Dave. I have used & machined quite a lot of Delrin / Acetal. It is funny stuff, almost greasy. I think you were on the right step with wet & dry. But i think something like car wax or similar maybe the way to go. Carnuba wax , which i use on fibre glass molds may work. My thinking is not cream or liquid car polish but the actual wax sort.

Like you say to much friction would mark it..

My local car accessory shop sells up to 3000 grit paper. Which i use when polishing rings etc. I guess the finer the better.

If you do not have any of the above let me know & i will have a go tomorrow on some & post the results.

Another thought is bumper, back to black for cars. It has silicon in it. ????

Steve.

Edited By Steviegtr on 15/12/2020 21:19:19

I've found I could get an attractive shiny finish machining with a sharp tool and a very fine feed, even if only taking a few tenths depth of cut.

Edited By Mick B1 on 15/12/2020 21:38:07

I get good results with spare bits of carpet….I have some off cuts from laying carpet and use them on the acetates but three methods, namely, rub the plastic part on the carpet piece,…or, apply directly to parts i nthe lathe,..or, just work the carpet piece against the part while it's in vice or hand.

……Only thing is, don't use used carpet pieces because they are contaminated with grit and other foreign bodies that score the plastic.

Can you paint it?

Roger,

Silicone oil works down to single figure of frost (say about -7C / 20F), but below that you need to use Vaseline on the door rubbers. How do I know? Cold weather testing in Canada down to -45C! Door key locks, in the days before 'plippers', we had to unfreeze with a Zippo lighter.