LATEX MOLDING COMPOUND
Kreemtex is a white, high quality, easy to use latex molding compound for detailed reproductions. Keemtex molding compound is supplied in concentrated form for spray or brush applications. Adding a small quantity of demineralized, or soft water with careful stirring may lower the viscosity; add a small amount of ammonia to the diluent water.
This compound forms a soft, flexible, good aging rubber film with a low shrinkage and will reproduce an intricate surface in exact detail. It has excellent storage stability and will not phase out or separate on long standing.
Color: White pH: 9.5 – 10.5
Base Polymer: Natural Rubber Weight: 7.85 – 7.95 lbs./gal.
Viscosity: Heavy Paste Total Solids: 73 – 76%
Fasten the model to a glass plate or other firm, non-porous object so that no handing will be necessary during application of the latex. The latex compound itself may be used as a cementing medium to fasten the model in place by simply placing a small quantity on the non-porous surface.
For brushing application, care must be taken to provide a smooth, even first coat, with all air bubbles carefully brushed out. Brush from the top of the model to the bottom, then continue on out from the base of a distance of about 1- ½ inches on the supporting medium. When dry, this marginal overlap provides a very definite aid to handling in later casting operations. The overlap should be applied on each application.
After the first coat has become completely dry to the touch, subsequent coats may be added, allowing each to dry to the touch until a satisfactory film thickness has been developed. Drying may be carried out at room temperature. The process will be greatly accelerated if a current of air from an electric fan can be directed across the surface of the model. Heat up to 180 degrees F can be used to further speed drying. The finished mold on the model must be thoroughly dried to obtain maximum physical properties and the mold should be further dried after removal from the model.
If the model has a relatively large surface area the first coat of latex should be applies as described above, but this must be followed with another, applied as spots of latex in a checkerboard design. After the application dries, the model must be given another over-all application in the usual manner. If the additional coats are to be applied, the checkerboard application should be interspersed regularly. This accomplishes a reduction in the tendency toward shrinkage and dimensions of the finished mold. The finished mold will be very close to those of the original model.