Re: RE: ATM 21" f/6 report: status and questions

[w2vy@xanthus.net]

>Over the weekend I finished grinding with #220 (after a total of 5 hours)
>and began with my next grit, which is SIC #320 microgrit.  Now for a dumb
>question:  What's the micron size of #320?  Or more generally, what's the
>conversion factor between microns and ordinary grit numbers?   My plan is to
>grind about 3 or 4 hours at #320, then proceed to microgrit WCA 12 micron,
>then WCA 3 micron, then begin polishing.  I already have these abrasives on
>hand.  Is this plan consistent with your recommendation?

I don't know the sizes off the top of my head, but I do remember
that #500 is very close (a little smaller than) 25 micron

Large jumps aren't bad, but it can yield more sweat for you
(or your machine :) )

Tom Moulton
w2vy@xanthus.net
http://www.GotGrit.com