Re: ATM 18" mirror Progress and Dental Stone question

["Richard" <richas@earthlink.net>]

I agree with all of this.  I only tried it once a long time ago, but plain
old plaster of paris can be used to make a disk.  You can coat it with
varathane, and then attach the tiles to it with epoxy glue.   You will learn
a lot when you do this.


----- Original Message -----
From: "David Harbour" <scarab@peakonline.com>
To: "Herb Kasler" <h.kasler@worldnet.att.net>; "Ken Hunter"
<kb7h@onemain.com>
Cc: <atm@shore.net>
Sent: Wednesday, July 11, 2001 6:15 AM
Subject: Re: ATM 18" mirror Progress and Dental Stone question


>
> Yes- Herb is right- there is no need to worry over dental stone.I make big
> tools with Portland cement/sand mix. See my earlier posting about how I
> build large portland cement channelled grinding tools. I've made many,
never
> have had a grain of sand fallout and cause any damage.  Tools are also
more
> stable dimensionally. ATM's should get away from the idea that dental
stone
> is somehow the ideal substrate for a channelled ceramic tool. It ain't
> (pardon my colloquialism). A few have written saying they've kept my
rather
> longish posting about how I make and use Portland cement/sand/waxxed
> channelled ceramic tile tools. If any missed it, and would like a copy, I
> still have it in my sent items folders and will be happy to forward it-
>
> Clear skies to everyone-
> Dave
>
> ----- Original Message -----
> From: "Herb Kasler" <h.kasler@worldnet.att.net>
> To: "Ken Hunter" <kb7h@onemain.com>
> Cc: <atm@shore.net>
> Sent: Wednesday, July 11, 2001 12:42 AM
> Subject: Re: ATM 18" mirror Progress and Dental Stone question
>
>
> >
> > Ken,
> >
> > FWIW, you can make a perfectly good tool without getting dental stone.
The
> > folks at the Chabot workshop here in the Bay area use plain old
concrete,
> > sealed with marine epoxy. They've made countless mirrors with it.  I
used
> > something called pourstone, which is a cement for anchoring fenceposts,
to
> > pour the tool for my 16" mirror. I sealed it with polyester resin (the
> stuff
> > you get for marine fiberglass) to keep any gritty bits from escaping and
> to
> > adhere the tiles to the face. The stuff is just a mixture of portland
> cement
> > and plaster of paris. It is really, really hard. You won't be able to
> break
> > it unless you take a sledgehammer to it or drop it off a 5-story
building.
> > It also resists moisture quite well, though the sealing makes that a
moot
> > point. I had no problems with it whatsoever.  I bet you can get it at
just
> > about any hardware store in Australia, and it's a lot cheaper than
dental
> > stone, too. I paid $20 for enough to make my 16" tool. You might have to
> buy
> > another $5 worth to make your 18"er. In the time it would take you to
get
> > your dental stone, you could be done grinding.
> > Later,
> > Herb.
> >
> >
>
>
>