On Mon, 30 Oct 2017 14:01:19 -0700, "Bob La Londe"
wrote:
I've got an old piece of granite counter top I glue wet or dry sand paper to
with 3M spray on contact adhesive. Its great for rubbing a mold face on to
remove burrs and to take out tooling marks on misc parts if I feel its worth
the time. Sometimes to just make the mill rolled side of a part look
better. Its not smooth, but its got a pretty good average flatness when
checked with sunlight and a steel rule. I use it because I don't want to
gunk up my surface plate with glue and abrasive grit. Even if my surface
plate already has two chips and its only B rated.
Yeah, not smooth. I wouldn't try to hone a plane blade on it.
I also sometimes use it with very coarse paper to level and take down an odd
project. A recent one was a cutting down a plastic bucket. I sliced it on
the bandsaw, and then squared up the cut end on my "sanding granite." It
really works better than it sounds.
I'll take your word for it.
Slight Background Tangent:
I use little rubber sanding blocks with 300 grit or higher to quickly knock
down the burrs on a mold face before I use the tool height setter to set the
next tool. (Sorry, no ATCs in my shop yet.) It works great. Better if the
part is still dripping with coolant. However the wet or dry sand paper just
doesn't hold up. Then one day I saw MSC had 3" wide emery cloth in bulk
rolls. I bought a roll of 300grit and neither of my little blocks has had a
piece of wet or dry on it since. When the emery is fresh I have to be
really gentle, but it breaks in quickly enough to a much finer grit. At
that stage it works for a few months before it wear through. The emery
cloth roll is expensive, but in the long run it saves me money and a lot of
time. The little ends under the flaps get tossed in the tool cart or tool
drawer for one of the lathes. They don't see any wear so they are still
nice little bits of full grit emery.
Back to the point:
What I want is to find some sheet size emery that is modestly affordable to
use on my granite sanding block. I have the same issue with the wet or dry
not really holding up very well when used wet. Sure its fine for a day, but
the emery I use on the rubber blocks is good for months. I found some for
sale somewhere once. Maybe MSC and I was absolutely floored by the price.
It would be nice to have some 100 grit for roughing on one end of the
counter top piece, and some 600 or finer on the other end for polishing.
http://www.supergrit.com/products/pr...ets-emeryflint googled.
I don't like to finish fine with the rubber block as they can ever so
slightly introduce an out of flat on flat surfaces. Just enough to knock
the burrs flat, and move on. If it takes out the tool marks I sanded to
hard.
Sanding by hand is an art. Have you considered a DIY or purchased
wide drum sander? You could build it to fit your largest mold and
then it could ostensibly handle anything that size or smaller.
https://www.pinterest.com/brad2179/d...ander/?lp=true
You could use emery instead of garnet paper.
Additional question: Why do you have to wet-sand?
--
The Road to Success...is always under construction.
--anon