Liquid Latex Mould Rubber — Brush-Built Skin Moulds

Primary uses

• Low-cost flexible mould making
• Glove mould production
• Air-dry moulding

Applications

• Glove moulds for plaster and concrete ornament
• Statuary and garden ornament production moulds
• Low-cost skin moulds where cycle time is not critical
• Craft and studio mould making

Advantages

• Very low material cost per mould compared with silicone or urethane systems
• Applied by brush with no mixing, which suits studios without weighing equipment
• Glove moulds strip easily off statuary and ornament with undercuts

Limitations to consider

• Mould building takes many coats and considerable elapsed drying time, so it suits shops with schedule slack
• Latex moulds shrink and degrade with age and exposure, so they are not a long-term mould library
• Air-dry behaviour depends heavily on shop humidity and temperature, which is a real constraint in Canadian winters
• Mix ratio, pot life, working time, demould time, full-cure schedule, hardness, tear strength, elongation, shrinkage, viscosity and temperature resistance are properties of one specific supplier system. They are never quoted here from memory or by analogy with a similar product; they are read from the supplier data sheet for the exact material offered and confirmed at quotation.

How to choose the right grade

• Start from the casting material and the number of parts the mould has to produce, because durability and detail pull in opposite directions
• Describe the pattern itself — its material, porosity, undercuts and whether it can be destroyed — since that decides the mould strategy before any product is chosen
• State the shop conditions the work happens in, including temperature, ventilation and whether the job is poured in a box or brushed on in place
• Be honest about the schedule — if the mould is needed this week, a coat-built latex mould is usually the wrong choice
• Confirm the pattern can tolerate water-based material and repeated brushing
• Mould-making and casting behaviour depends on the pattern, the shop temperature and humidity, the mixing method and the operator. A production-representative trial on your own pattern and in your own shop conditions is the only honest way to qualify a material before a run is committed.
• Exact specification is confirmed against supplier documentation at quotation.

Typical grades

• Brush-on products for glove moulds on statuary and ornament
• Products the supplier distinguishes by solids and film-building behaviour
• Buyers search this category by grade name, and those names describe what the workshop needs rather than what is asserted here. Which grade a specific offer corresponds to, and what the supplier declares for it, is read from the technical documentation issued for the exact material quoted.
• Materials in this category interact: rubbers, releases, sealers, resins, pigments and fillers can inhibit cure, stain a surface or shorten mould life when they are combined outside the combinations the supplier has tested. State every material already in the process at enquiry so compatibility is checked against supplier documentation rather than discovered on the shop floor.
• Reactive materials age in the container, and moisture-sensitive systems age faster once opened. Order against real consumption rather than against a discount, and confirm the shelf life the supplier states for the exact product and pack.