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Rubber molding on fossil mastodon ivory

I don’t really care much for the liquid rubbers. Does anybody know
if the low temp vulcanized materials like Castaldo’s VLT Blue
silicone is safe for using on fossil mastodon ivory?

Stephen Walker

Hi Stephen;

Does anybody know if the low temp vulcanized materials like
Castaldo's VLT Blue silicone is safe for using on fossil mastodon

I don’t know about the VLT Blue, Michael Knight of Castaldo would be
glad to offer his advice, I’m sure. Castaldo also makes a 2 part cold
curing rubber that I’ve used with excellent results. Just weight out
the two compounds, 50/50 and knead them together, then clamp into a
mold frame. They’re different colors so you can tell when they are
completely mixed. The compounds are like soft putty, and they cure at
room temperature in about 15 minutes (better work quickly!) but they
need to be under a little pressure to fill and cure properly. I can’t
remember the name and I’m not in the shop at this time, but you can
find the stuff in the Rio catalog, possibly Stuller carries it too.

David L. Huffman

Hey there. In regards to molding anything that is a fossil: it
depends on how it is preserved and how completely. Heat can
definitely break them down. As a caveat I haven’t worked with any
fossilized ivory at all, but I would be really careful. When I worked
in museum collections for paleontology, we had to keep all temps and
humidity at certain levels because even the fossilized bones that
looked so solid, could, and often would break back down, and powder
when touched, from the heat. We used latex rubber to mold most
things, and then cast into that.

Dear Stephen,

This is Michael Knight at CASTALDO.

VLT should work very well.

Two small cautions, however. It’s always a good ideas when tackling
anything new or out of the ballpark to try it out on a small scrap
or waste piece. You never know. If you have something similar or a
crumbled piece of the fossil ed bone, that would be great.

The other concern is if the fossil is porous. The rubber might flow
into the pros and make it hard to remove. Or get stuck there

The so first check it out with a strong magnifying glass. If you see
pores or have any doubts, you can coat the fossil with some sort of
barrier. Spray polyurethane from the hardware store works. Maybe you
can find something else that is compatible with fossilized mastodon

Good luck!
Michael Knight

there is a site that deals almost exclusively with stabilizing
paleo/fossil pieces - i have used their
adhesives in every viscosity, from water thin to gap filling,
followed by the activator-catalyst in a hand pump bottle. at one time
they had a ‘starter kit’ with samples of all the adhesives and their
debonder. their debonder was developed to remove cyanacrylic glue
from skin without burning - even lips - (don’t ask) but i’ve also
used it to safely remove every form of adhesive, epoxy, paint, etc.
from anything - including pearls or turquoise or lapis, every stone.

good luck -

who’s back from tucson and wondering: ‘what will my partner do with
the 5900 pounds (3 pallets with a $1900.00 shipping bill) of
material from tucson on top of (and in back of, and next to, and
underneath, and between) the other tons of stuff already here?’