Latex or liquid rubber is a natural material for making films, masks, skin, special effects or costumes. Also for making so-called "syrup moulds". For syrup moulds, apply at least 6 layers of latex with a brush. BICK latex dries in the air. A heat source of up to 70 ° C increases the polymerisation. Apply talc to the outside of your mould before demoulding. The cured latex retains its properties longer at 70 ° C (on the heater). Latex can be coloured, can be thickened with latex thickener. Easily demoulds onto plaster.
Can be dyed with the dye for latex
More detailed information;
Latex
Latex is the thickened sap of the latex tree. It is a dispersion of rubber in water. When it dries, the rubber particles fuse together to form a strong whole.
Liquid latex contains the preservative ammonia, dried latex no longer smells of ammonia.
Latex is often used as a moulding material in the sculpture world. It is very stretchable, tear-resistant and inexpensive. Disadvantages are shrinkage, instability against various substances such as polyester resin and wax at 80 ° C (candle casting). In addition, applying the latex with a brush is rather tedious, although the latex paste can be advantageous here. Latex and latex paste must be stored frost-free.
Instructions:
The most common method is to apply a few layers of liquid latex to the mother model with a brush. A release agent is not normally required. Metals can be attacked (copper), but conversely liquid latex is also attacked by some metals (copper, tin and to a lesser extent iron). To be sure, do a test first.
Latex can be coloured by mixing in water-based pigments or by making such a pigment by rubbing powder pigment into water. Always test first whether the pigments and the latex are mutually compatible, also with regard to the durability of the coloured liquid latex. Sometimes it coagulates (stiffens) after a few hours / days by adding fillers or pigments.
When one coat is dry, apply the next coat until a sufficient thickness is reached. The drying time of a layer depends on the humidity, temperature and air circulation. The latex is dry when the white colour has changed to a more or less transparent yellow-brown colour
Rinse the brushes etc. with water after use, before the latex has dried. Thick areas, edges etc. can be filled quickly with our latex paste. It goes without saying that such a thick layer of latex paste takes longer to dry. Latex and latex paste can be mixed together in any ratio and thinned with water.
Another method of applying the latex is to hang a plaster master model in the latex for some time. The moisture from the latex penetrates the plaster and creates a latex cake on the master model, so that a thickness of a few millimetres can be achieved at once. Connecting a vacuum line in the part of the master model that protrudes above the latex allows for an even thicker layer and also prevents escaping air from forming bubbles in the mould.
We have a coagulant for professional users. With this one lubricates a mother model and by dipping it into the latex a latex layer of one to two millimetres grows within a few hours.
After applying the latex, it must be dried to a transparent yellow-brown layer. Due to the drying shrinkage, this layer may peel off from cavities. In order to place this rubber layer tightly around the master model and prevent it from peeling off, the master model can first be applied to these cavities with a layer of plaster varnish.
Re-channeling at 60-70 ° C is not absolutely necessary, but improves the strength of the rubber.
For larger moulds it is necessary to use a support mould. This can be made of plaster, concrete or polyester. When making this support mould, the master model must still remain in the mould.
For the life of the latex mould, it is beneficial to put it in water for a day after drying so that the vulcanising chemicals are drawn out. These chemicals will otherwise affect the rubber over time. Then powder the outside with talc to prevent stickiness and the mould is ready for use.
Latex moulds are very suitable for casting plaster and concrete objects. Depending on the thickness of the latex mould, some polyester castings are also possible. Be aware of the high temperature that the hardening polyester can reach.
Frequent casting of plaster and concrete causes it to adhere more and more to the latex. We have a special silicone-based release agent for this. Never use Vaseline, mineral oil, petrol, wax (turpentine) to grease or clean latex.
Technical worksheet:
Natural latex with low ammonia content Technical data sheet Technical data Total solids content (TSC)%: 60.3 Mechanical stability (sec.): 800 min Ammonia content (%): 0.38 Ford Cup 3 Viscosity at 25 ° C (sec.): 30.5 pH: 10.6 Ageing modulus at 700% (MPa): 11.8 Non-aged tensile strength (MPa): 25.0 Age (22 hours at 100 ° C) Modulus at 700% (MPa): 50 min Age (22 hours at 100 ° C) Tensile strength: 75 min Product form(s): Liquid Packaging option(s): Drum, IBC, Bulk, Bottle, Canister