470 E. BONITA AVE., POMONA, CA 91767
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Latex Brush-On Rubber
RL-461
Product Data Sheet
RL 461 is a one-part, brush on, medium solids liquid latex that is applied in layers to build a highly tough, tear resistant and
durable mold rubber. Molds are best used to cast plaster and concrete. It is also works well as a texture pad for decorating
concrete or clay models. Latex needs to semi dry between coats as multi layer molds or parts are being created.
Available Sizes: Pint & Quart, Gallon & 5 Gallon, 55 Gallon Drum
TYPICAL PROPERTIES OF CURED RUBBER
Durometer: 40 Shore A
Coverage: lb, 1 ft
2
x 1/16 Thick
Accessories
RL-Thinner Add to adjust latex thickness Better than adding just distilled water!!
RL-400 T Thickener, ground black organic rubber use for plugging undercuts in molds
Burlap Cloth use for reinforcement
MR-100-50 Casting release used for concrete and plaster to improve surface finish
CO-1 Castor Oil release used for concrete and plaster
Model Preparation:
Model s surface should be clean and free of oil and dirt. Oil clay, wood, stone, and glazed ceramics normally don t need to be
sealed. Plaster, concrete, water-based clay, copper containing items should be sealed with shellac or compatible sealer. For all
other surfaces, run a small test to ensure compatibility if latex sticks or turns dark, apply sealer. Next, secure model to a base
board plywood or something similar.
Processing & Curing Instructions: Mold Making
Fasten the part to be molded to a firm base so as to avoid handling piece during brushing No release is necessary in
most cases unless part is highly porous then sealer is applied. When brushing on latex, care should be taken to brush out all
bubbles to assure a smooth, detailed first coat so void-free positives can be made. Brush from the top of model to bottom then
continue on out from base, a distance of about 1.5 – 2 , to create a supporting flange. Continue to build-up flange with each
successive layer of latex. When dry, flange provides an aid in the handling of mold during casting process.
After the first coat has become dry to the touch, subsequent coats may be added allowing each coat to dry before
applying next coat. Depending on environmental conditions the drying time will change from hours to portion of a day 4 to 16
hours. Drying time depends on temperature and humidity and can be improved by the use of heat and moving air over the
surface, with 1 to 2 coats per day. When dry, latex will change color from creamy white to a light tan. Mold consists of 8 to 20
coats depending on desired thickness and latex system used. Thickness ranges between 1/8 and inch thick. Each additional
coating should be brushed in alternating directions (top to bottom, right to left, diagonally) with a checkerboard coat in between
so a laminated structure is created. Applying this technique reduces the dimensional shrinkage of the finished mold.
For deep undercut areas, use RL 400T (thickening/plugging filler). Add to latex system until desired paste is created
a thick peanut butter like consistency and apply to outside latex mold. Once area is filled and allowed to dry, usually within the
hour, brush a final coat of straight latex to seal up area.
To maximize the strength properties of the mold, allow it to fully cure in a warm area for 1-2 weeks before placing into
production. Otherwise, accelerated cure can be achieved if mold is warmed in an oven at 100 to 150F. Once mold is fully cured,
a mother mold support is made out of fiberglass or plaster to support the latex mold.
Using Mold:
Avoid contact with copper containing metals, oils or solvents. When casting with concrete and plaster, using a casting release
MR-100-50 or CO-1 (Castor Oil) is recommended. Wetting the mold s surface prior to casting will assist in eliminating air
bubbles from the mold s surface. Clean latex with soap and water. Keep cured latex rubber out of direct sunlight.
Storage/Shelf Life
Store liquid material in cool, dry area out of direct sunlight, in tightly sealed containers, above 60F. Use within 6months. Do not
allow liquid material to freeze which will damage latex causing irreversible coagulation.
THE INFORMATION AND DATA CONTAINED HEREIN ARE BASED ON INFORMATION THAT WE BELIEVE TO BE RELIABLE. EACH
USER OF THE MATERIAL SHOULD THOROUGHLY TEST ANY APPLICATION, AND INDEPENDENTLY CONCLUDE SATISFACTORY
PERFORMANCE BEFORE COMMERCIALIZING. SUGGESTIONS OF USAGE SHOULD NOT BE TAKEN AS INDUCEMENTS TO
INFRINGE ON ANY PARTICULAR PATENT.