Sculpture Tools Materials Supplies Art Supplies and Equipment



SURFACE TREATMENT OF VARIOUS MODEL MATERIALS
WHEN USING A VARIETY OF MOLD MATERIALS

To use this chart, first find the material that your sculpture is made of in column number one. Next find what kind of mold material you would like to use in the second column. In the third column you will find suggestions for treating the surface of your model in order to use the mold material you have chosen. And finally, the key at the end of this section will describe by number each of the suggestions. Generally, recommendations are given in order of preference.
MODEL MATERIAL MOLD MATERIAL SURFACE TREATMENT
Plaster, wood, cement, porous stone,
unglazed fired ceramic.		Plaster
Latex
Polysulfide
Polyurethane
Silicone
2+3 or 4;7
2;2+6;1
2+5,6 or7
8;2+4,5,6 or7
2+5,6 or7
Dry water based clayPlaster
Latex
Polysulfide
Polyurethane
Silicone
3;2+3,4 or7
1;2;6;2+6
2+5,6 or8;1
8;2+4,5,6 or 7
1;2+5,6 or7
Wet clay or plasterPlaster
Latex
Polysulfide
Polyurethane
Silicone
 3;4;7
2 (not recommended)
1;5;4;7
8;2+4 or5;7;4
1;5;6;7;2+5
Metal*Plaster
Latex
Polysulfide
Polyurethane
Silicone
3;4;7
2;1;6
5;6;7;1
8;4;7;6
1;5;6;7
Polished stone, glazed ceramic, glassPlaster
Latex
Polysulfide
Polyurethane
Silicone
3;4;7
1
1;5;6;7
8;4;5;6;7
1;5;6
Plastics (ABS, acrylic, nylon, polycarbonate, styrene,
polyester, epoxy, polyurethane)		Plaster
Latex
Polysulfide
Polyurethane
Silicone
3;4;7
1
1;5;6;7
8;4;5;6;7
1;5;6
Plastics (polyethylene, polypropylene)Plaster
Latex
Polysulfide
Polyurethane
Silicone
1;4;5;6;7
1
1
1
1
WaxPlaster
Latex
Polysulfide
Polyurethane
Silicone
4;3
1
1
1
1
Plasticene (oil clay)Plaster
Latex
Polysulfide
Polyurethane
Silicone
3;4;7
2
1
8;4;5;7
1;5;2+5

Note: By no means is this list complete; there are probably other materials that will suffice as pattern releases, but we know these WORK. In general, surface treatments are given in order of preference. We suggest that when using a new mold material always test for compatibility with any given model surface. The following is a brief formulary for some of the release agents given.

Stearine/Kerosene=1 part melted stearine:2 parts kerosene
Soap Solution=1 part potter's soap:4 parts water
Petrolatum/Naphtha=1 part petrolatum:10 parts naphtha (mineral spirits or paint thinner will work for this as well)

*Latex will react with nonferrous metals such as copper or brass so seal first with shellac or lacquer. Also polysulfides and silicones will sometimes react, so when in doubt, seal the surface.
**Being black, polysulfides will sometimes stain a stone surface; seal first.
***Silicone will sometimes bond to an unsealed ceramic or glass surface; coat with petrolatum/naphtha.
****Polysulfide applied directly to ABS, styrene or polyester will react; seal first.
*****Some polyurethanes will react or become inhibited when used with oil clays containing sulfur. (Roma Plastilina, Chavant) Seal first.
******Some silicones will react or become inhibited when used with oil clays containing sulfur. (Roma Plastilina, Chavant) Seal first.

KEY:
1. Nothing
2. Seal with shellac or lacquer
3. Stearine/kerosene
4. Soap solution
5. Petrolatum/naphtha
6. Paste wax (Johnson's, Trewax)
7. Petrolatum
8. Universal Release#
(#Registered trade mark Smooth-On, Inc.)