Recipe for "Cast Marble"

[Keston Helfrich]

Hello All,

I was searching the google archives the other day and came across a
recipe for concrete using portland cement and crushed marble
(limestone?). I neglected to write it down and can't seem to locate it
now. I just need to cast a solid block (about a cu. ft.) for a base,
and would like to be able to polish it up when I'm finished.

Thanks,

Keston

[Battersby]

Keston Helfrich wrote

Two parts marble chips, one part white portland cement. By weight.

--
T. M. Battersby, stuccoist.
http://www.battersbyornamental.com
tbatt...@satx.rr.com

> Thanks,
>
> Keston

[Gary Waller]

Hi Keston,
In my tiny, little world 'cast marble' would most likely be polyester resin
with various fillers and dyes - you know the fake marble and onyx sinks,
garden ornaments, etc? If you want this finish, highly polished and waxed,
polyester is fairly cheap and fast. There is probably a local shop who could
cast it for you.

There are some concrete recipes using white cement, and more commonly
plaster recipes using "Keenes Cement" (try a search for scagliola for
example) - the key factor is to use the materials which you have available
locally. Crushed white, sparkly, marble sand is pretty well only available
from italy, and even there it is dusted in the mold for the surface only. A
fairly white, low cost powder (not too good in concrete - you still need
some type of sand and pebbles) is calcium carbonate, the next whitest and
higher price is aluminum trihydrate, and the whitest (at these cost levels)
is titanium dioxide - these should be used like pigments, to tint the white
cement and whitest sand you can find (probably silica sandblasting sand).
Still other recipes use lime putty - which is brilliant white - and white
sand - the lime eventually recarbonates back to calcium carbonate (same as
limestone and marble).There are other concoctions as well - but these will
require you to source ingredients such as aluminum sulphate (alum) and
potassium silicate (water glass). The cast marble I like must have a
crystalline, translucent quality and any open veins must have a bit of
sparkle. I use diamond dust for the sparkle (don't worry - its cheap).

So this seems an easy question but, at least for me, is hard to answer - it
depends on the quality you are after, if the piece will go outside, and
where you live.

Gary sculptari
Vancouver

"Keston Helfrich" <kes...@core.com> wrote in message
news:3b524499$0$18887$1dc6...@news.corecomm.net...

[Dan Spector]

The place to get marble sand (very fine) is at the factories where they make
those cultured marble sinks etc. I think they look like melted ice cream.
But these people buy 50 lb. sax of the sand and of a finer dust. They should
be willing to sell you a couple of sax. Combine 2 parts chips, 1 part marble
sand, and 1 part wht portland.

--
Dan
<arch...@earthlink.net>
http://www.archicast.com
> From: Keston Helfrich <kes...@core.com>
> Organization: CoreComm LTD - Chicago, IL
> Newsgroups: alt.sculpture
> Date: Sun, 15 Jul 2001 21:35:12 -0600
> Subject: Recipe for "Cast Marble"

[Keston Helfrich]

Thanks for alll the info. I poured a sample of a mix of portland and marble
chips/dust a couple of days ago, I demolded it and it looks pretty good-I'll
try a little polishing after its cured for a few more days.

Thanks again for all the help and advice,
-Keston

"Keston Helfrich" <kes...@core.com> wrote in message
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