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moldmaking

updated thu 5 nov 98

 

John H. Rodgers on sun 23 nov 97

-- [ From: John H. Rodgers * EMC.Ver #2.5.02 ] --

Since arriving in Alabama for the winter I have been approached by several
people about making molds and possibly teaching a moldmaking class. If
anyone would like to have molds made, or if you are in the southeast region
and have an interest in a mold-making class seminar, drop me a note via
private e-mail. If there is enough interest perhaps a class/seminar can be
arranged.

Thanks

John Rodgers
Was a bright and sunny day in Alabama today. Watched a pair of redtailed
hawks soar over a hardwood covered ridge today. Could clearly hear their
call. Magnificent!! Really touched the memories of growing up in the South.

Ditmar/Gayle on wed 4 nov 98

For a very fragile model I'd recommend making your first mold of an
alginate based material. Basically the same type of material that a dentist
uses to make impressions of your teeth. The most commonly available is Mix
a Mold.
You can find it in craft stores. Other brands are out there, some are in
kits to mold hands, etc. Sticking shouldn't be a problem, but since the
shell is calcium carbonate, and the gelling chemistry of the alginates use
calcium in the formula......... to be safe, brush on a thin coat of
release, like oil.

Cast the piece in a hard wax ( jeweler's or casting wax ) and use the wax
to make multiples. Or just cast the plaster right into the alginate for the
stamps. You should be able to get lots of casts from the one mold before it
dries and needs to be discarded. Either way, it's a good idea to have the
master MODEL out of wax, so you can reproduce the shell without using it
and risking breakage. With a wax, making a master MOLD with silicone or
rubber is less problematic.

From Alohaland, Ditmar.