Using a collet on shiny things, how to preserve the surface finish?

[whitmore]

The collet just scrapes the shiny gloss finish in places when I insert the tubing.

In addition to the other suggestions, it is possible to make a pot chuck, and instead of tightening
grub screws, position the workpiece in the pot and pour in a little plaster of paris.
After it hardens, it won't slip or scratch, and a bit of warm vinegar will remove it handily.
Centering and alignment, of course, aren't as simple as with a collet.

 

[Jimsehr]

I just checked eBay and you can buy an 5c emergency collet for less then 15 bucks. Shipped. If you bore that collet to size you won’t get any scraping on the part . So no marks. Plus you can keep that collet size or bore a larger size bore if ever needed. Plus you can use the back of the bore for a collet stop. I know I can bore a soft collet faster then making a bushing of any kind.

Jimsehr

 

[ThinWoodsman]

I just chucked a shiny aluminum ring that I mucked up when parting last night. Used painter's tape (the blue stuff) around the circumference to protect it from marring while I re-faced it. Worked well; give it a shot. Far easier than juggling copper or brass shims (for which, yes, I know, double-sided tape).