USG Industrial Plasters and Gypsum Cements for Foundry Applications - Manual

USG Metal Casting Plaster
A blend of plaster and refractory materials
formulated for producing low-permeability plaster
molds. Designed for casting aluminum matchplatyes,
cope-and-drag sets, core boxes, loose patterns,
prototypes, housings and plastic mold tooling.
HYDROPERM Gypsum Cement
A formulated product incorporating an air-
entraining agent to provide permeability. For
producing permeable plaster molds to cast many
non-ferrous metals and alloys.
Medium High-Expansion HYDROCAL Cement
A formulated product to give uniform expansion of a
pattern in all directions, equal to the shrinkage of
aluminum or zinc alloy metals (Kirksite, Zamac,
etc.). Normal growth range is
1 ⁄
16
to 3 ⁄
16
inch per foot.
The Plaster Mold Casting Process
Is Superior To Other Methods When . . .
• You need fine, intricate surface detail.
• You want to use parts in an as-cast condition.
• You want to reduce or eliminate post-machining of
castings.
• You need better dimensional accuracy for cast-to-
size parts.
• You need to cast thin metal sections, not possible
with other methods.
• You need to produce complicated shapes with
intricate core structures.
• You cannot justify the higher pattern or die costs
required by some casting methods.
• You want to do short run or prototype castings
economically.
IG-279/10-92
Industrial Plasters and Gypsum Cements for Foundry Applications
Trademarks: The following trademarks used herein are owned by USG
Corporation or its subsidiaries: USG, HYDROPERM, HYDROCAL.
Note: Products described here may not be available in all geographic markets.
Consult your local representative for information.
Notice: We shall not be liable for incidental and consequential damages,
directly or indirectly sustained, nor for any loss caused by application of these
goods not in accordance with current printed instructions or for other than
the intended use. Our liability is expressly limited to replacement of defective
goods. Any claim shall be deemed waived unless made in writing to us within
thirty (30) days from date it was or reasonably should have been discovered.
Copyright 1992, United States Gypsum Company Printed in U.S.A.
Typical Physical Properties
Use consistency Maximum
(parts of water Hand mix setting Approximate density
by weight per 100 setting time expansion (lb./ft. 3 )
Product parts of plaster) (minutes) (%) Wet Dry
USG Metal casting plaster 130 25-30 0.100 84.6 41.0
Medium high-expansion H YDROCAL cement 48 25-35 1.050 108.7 —
H YDROPERM gypsum cement 100 12-19 0.140 40.0 —