To: jkillea{at}yahoo.com, atm{at}shore.net
From: mdholm{at}telerama.com
Reply-To: mdholm{at}telerama.com


Can you get the tiles that are stuck together on the back to make a mat? 
If not, you might be able to make your own by gluing the tiles to some
coarse woven sturdy netting.  I am thinking of the kind of netting used to
make cross stitch.  You get it at fabric and craft stores.  Chicken wire
might work too.

The reason I ask is the amazing ease I had making an 8-inch tool using the
tiles in dental stone method.  From what I have read, Hydrostone is pretty
equivalent in behavior and final properties to dental stone.

Here is the method in a nutshell.  Prepare the mirror in the same way as
for a hydrostone tool.  Lay the mat of tiles face down on the prepared
mirror.  Mix up the goop and pour it on top of the tiles.  Shake the stack
back and forth a few times and bang it down on the workbench a couple of
times (not too hard with the banging).  Poke into the wet goop with a very
thin implement like a wire, or a bamboo teryake skewer (they are at my
grocery store).  The purpose of poking is to make sure the tiles are down
against the mirror and not floating up in the goop.  Bang it once or twice
more to help close the holes from poking.  Let it cure to initial hardness.
 Separate.  Take the tool out to the driveway and grind the back roughly
flat against the concrete before the stuff gets too hard.

The only tricky part is that the mixing, pouring and any other step that
has to be accomplished while the stone is still liquid has to be done
rather quickly. This stuff sets up fast!

I found the whole process amazingly easy and, despite my nervousness the
first time, a lot of fun.  Besides that, it produced a fine tool that
worked well through all the smoothing and fine grinding stages.

www.gotgrit.com has the tiles in mat form and dental plaster if you run out
of hydrostone.

The procedure above, including poking, came from the instructions supplied
by gotgrit.  I think they were originally written by Richard Schwartz.

BTW, probably want to store that unused hydrostone in the most water vapor
proof container you can manage.  I'll bet a round of beers that it will
absorb water vapor out of the air and become useless in a few months.

Mark Holm
mdholm{at}telerama.com

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