Polishing buttons

[Tiposx]

I am experimenting with turning buttons from acetal on my lathe. I can achieve a nice finish with sharp tools, but what I want is a high shine. I have heard of polishing with oiled wet-and-dry emery but not tried it yet. Has anyone experience of polishing acetal or delrin?

I have been reading Alex Holden's blog which is a really helpful resource for construction and repair.

Tiposx

 

[Jake Middleton-Metcalfe]

use fast cut plus and cotton wool, run the lathe pretty darn fast and hold the cotton wool (dipped in fast cut) against the button, works well in general but its a bit slow. A quicker non lathe approach is to use a high speed polishing mop mounted on a bench grinder motor and a fine polishing compound on the mop (the same sort of thing you might use to polish a bit of brass). Rotate the button slowly while polishing - this approach is quicker but potentially easier to polish away bits of the button unevenly as its a bit aggressive, if you use the latter technique be careful as you do it but it can be made to work well. 

Edited March 23, 2019 by Jake Middleton-Metcalfe

[alex_holden]

I used acetal buttons on my first instrument and I flame polished them. Expect to melt a few before you get the hang of it. There's a video here:

 

 

[Tiposx]

Thank you Jake and Alex. I hadn't thought of using a flame. I will try both methods on a few test pieces.

The 3M Fast Cut is expensive and in big bottles for my needs, so I might try a different brand.

[Jake Middleton-Metcalfe]

wow I havent seen flame polishing on acetal before, I have seen it done on clear acrylic though. 

 

If fast cut is a bit pricey you might get a decent result with brasso on a soft cloth and polishing it by hand in the lathe - though I cant be sure. It will probably be slower than the fast cut, but you probably have a can in the cupboard somewhere!