Thread: boring silicone grommets

Does anyone have any experience with boring silicone grommets in a lathe?
I think I have the workholding down, but the problem is the tool. I used a 3/8 2 flute endmill oriented like a boring bar to get a high shear angle, but it made a nasty finish and just kind of pushed the material out of the way.
I don't know the exact type of silicone it is, but one was brown and one was yellow. The yellow one was quite a bit firmer.
It is 1.025 OD x .5 Id x .78 long and I need to bore it to .55 dia.
Any help is greatly appreciated.

Freeze and bore, or room temp and grinding pin/die grinder fixtured to tool post. And by freeze, I mean dry ice, not just ~0F.

Yup, drop it in liquid nitrogen. Or grind, but before you go jump on the grind wagon, understand it takes a minute to get a system down. A few or several set up pieces.

R

A coarse, 40-60 grit, diamond grinding pin works best.

Originally Posted by DavidScott

A coarse, 40-60 grit, diamond grinding pin works best.

Is that frozen or not?

Originally Posted by EnderDRM

Is that frozen or not?

Not frozen.

Originally Posted by EnderDRM

Does anyone have any experience with boring silicone grommets in a lathe?.

Do you mean SILICON?

DavidScott, where do you get those 40-60 grit grinding pins?