Is it possible to cast plaster?

Jewelry Discussion
1

This may be a stupid question and obvious - but I really don’t know
so here I am! I came across some funky plaster items that I would
like to try and incorporate into some of my jewellery pieces. Is it
possible to cast these as is or do I need to make an RTV mold of it
first? I’ve only got one shot at this so I’m hoping to do it right
the first time!

Many thanks,
Jennifer

2 
This may be a stupid question and obvious - but I really don't
know so here I am! I came across some funky plaster items that I
would like to try and incorporate into some of my jewellery pieces.
Is it possible to cast these as is or do I need to make an RTV mold
of it first? I've only got one shot at this so I'm hoping to do it
right the first time!

It won’t burn out like wax or plaster if that is what you are asking.
Plaster of Paris AKA gypsum plaster is the main ingredient in casting
investment.

3

Make a rubber mould, even latex will do. If you’re concerned get a
mould maker to make the mould for you.

I would recommend “stone”, hydrocal, or some other hard plaster for
the final pieces.

Regards Charles A.

4

Jennifer- it would be best to make an RTV mold and inject a wax.
Plaster does not burn out like wax would. After all we invest the
waxes in plaster to melt them out.

Have fun and make lots of jewelry.
Jo Haemer
timothywgreen.com

5 
However if you wanted to... you could make it into rocket science
(mwah ha harrr).

Indeed. Kepler’s Law states that all orbits (and therefore rocket
trajectories, natch!) are defined as sections of ellipses. A straight
line would be considered as the degenerate case.

Andrew Jonathan Fine

6

If you heat them above 115deg C then they will start to lose their
water of crystallisation andwithout care they will crumble away. You
cannot cast hot metal around them so you will need to make copies in
a more durable material. RTV moulding will be suitable as it doesnt
involve heat.

Nick

7

First, are you going to be “copying” somebody elses work if you cast
these items? It sounds like you would be and at this point I would
tell you to stop unless you can get some sort of signed agreement
with the originator or owner of these designs.

To actually answer your question, you cannot plaster cast a plaster
item so an RTV would be necessary to get a wax.

Again, I REALLY dislike folks “ripping off” other artists work,
so if you do not have permission from the owner of the copyright on
these pieces, DON"T COPY THEM. If you are an artist, make something
that is “your own design” and not a copy of the piece(s) you are
interested in, and use it/them.

John Dach