Re: [ATM] Trouble getting CeO off of bevel

["Bob May" <rmay@nethere.com>]

Beveling should be done BEFORE you start grinding the surfaces!
Doing it after you have a fine finish on the glass can provide
lots of scratches if you rub the grit that falls off of the stone
all about on the surfacee.
PPlease note that the big reason for the bevvel is to prevent the
glass from spalling off the sides of the disk and not some
appearance thing.  Once you have started a polish, there is no
real need for a bevel of any real size as the spalling action is
virtually nil.  he bevel doesn't need to be large as the glass
will not spall out pieces as long as there is a bit of a ledge
for it to work with.    Thus, there is usually no need to do any
beveling of the edge once you get past the 320 grit stage.
Sandpaper is noted ofr having a numnber of different sized grains
on it due to the gluinbg of the grit onto the paper.  This
problem is easily eliminated with good sandpapers by running the
paper over a fairly sharp corner of a block of steel before using
the paper.  This actionn tends to break off the high spots of
glued on grit and allows the majority of the grit to work without
interference.  You've probably noticed this  as partially worn
sandpaper seems to make a much smoother surface gtheen fresh
sandpaper does and it is because all of the high grains have
already been knocked off by using the sandpaper.  People often
toss sandpaper away just as soon as all of the high grains are
knocked off, tossing out perfectly good sandpaper which is
finally cutting a smooth surface.
When I'm using a stone in beveling, I always do the work under IN
a bucket of water so that the grains that get knocked off of the
stone immediately fall to the bottom of the bucket rather than
stay on the surface of the glass.   I( also don't slide my hands
around on the glass surface of improtance as I may have a trapped
grain somewhere and that will cause a scratcyh on the desirable
surfaccccce which will then need to be ground off.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


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