Dear Folks, I have a large incredible carnelian intaglio that is
driving me nuts. I am trying to get good impressions of it to cast.
Injection wax is not working, and I have tried chilling the seal.
Tonight I just used a paper based clay to make impressions, but
don’t expect to be able to cast that, as it is also water based,
investment will probably melt it. I will try however. I am using a
wax I got off ebay with a glue gun, and that is the only way I have
gotten good impressions, but maybe 1 of 3 is usable. I did cast one
that came out well. I am about to go back at it with the glue gun
tonight.
I am asking two things. One, does anyone have suggestions for
material for impressions. I have not tried sculpy or Fimo clay. Does
that burn out? Two does anyone know of someone that will duplicate
an intaglio by ultrasonic? I have not asked my German source yet.
The intaglio is about 1.25 x 1 inch. It is in an overpolished 9K
seal mounting that has been repaired, and I broke one of the struts
pressing hard. I will have to dismount the stone to repair or
remount the stone. The carving is a classical male profile, most
likely Alexander. The detail is so fine that there are tiny zodiac
animals on the rim of the shield. It is quite a piece. I want to
mold it in cold compound at some point as well. I guess I can’t have
too much of a good thing…repro, repro, repro…
Belicold molding compound from Rio might work for you. It comes as 2
putties that you mix, gives pretty good results, and has release
compound mixed right in.
I have not tried sculpy or Fimo clay. Does that burn out?
I do not know if they burn out, but I do know they can be toxic -
especially when heated above their normal baking temperature.
From “The Artist’s Complete Health and Safety Guide”
third edition, by Monona Rossol, 2001, page 285, published in USA.
'Exposure to DEHP is worrisome, because it causes liver cancer and
birth defects in test animals. DEHP has been listed as a carcinogen
by the International Agency for Research in Cancer (IARC) since 1982,
Three U.S. agencies also consider it a carcinogen . . . Around 1990,
Polyform Products replaced the DEHP in Sculpey with a chemical called
di(2-ethylhexyl)terephthalate, or DEHTP. Eberhard Faber replaced the
DEHP in Fimo with a mixture of three phthalate plasticizers. All of
these chemicals are very similar to DEHP, but have never been studied
for cancer effects. Unfortunately, the Labeling of Hazardous Art
Materials Act allows products containing these untested chemicals to
be labeled “nontoxic.” ’
“Overheating by mistake in case of hardening in a oven can release
hydrochloric acid as vapor.” This is claimed to be from an Eberhard
Faber safety data sheet. No date is given, so it is not clear if the
data is for the current formulation.
(apparently the owner of or distributor for Eberhard Faber) “FIMO is
Non Toxic and carries the CE mark. However, care should be taken when
baking as overheating (burning) can produce a gas.” (Note that they
do not say which gas.)