Foam latex is a type of rubber made from a number of components that are whipped with air into a light, frothy substance. It is then poured into a mould or in flat sheets and baked to a finished form. Foam latex is used in a variety of fields, from make-up to costuming to puppetry. The material is very sensitive to a number of factors including temperature, humidity and ammonia content. Foam rubber can be made at home. Don't get discouraged if it does not turn out right the first time; it may take a few tries.
Brush foam latex mould release into the mould or baking tray being used. The baking tray is for flat sheets of foam rather than a specific shape, for which a mould is used.
Allow the mould release to dry and buff off any excess build-up.
Pour 150g of latex base into a mixing bowl, followed by 30g of foaming agent and 15g of curing agent.
Measure 14g of gelling agent in a separate cup.
Mix the foam at the following speeds:
1 for 1 minute (elapsed time 1 minute)
10 for 4 minutes (elapsed time 5 minutes)
4 for 1 minutes (elapsed time 5 minutes)
1 for 4 minutes (elapsed time 10 minutes)
Note: These times are for a KitchenAid mixer. For other brands, see the references.
Slowly add the gelling agent after 10 minutes. Drizzle it in over the course of 30 seconds; do not dump it in.
Allow the foam to mix for 1 more minute.
Remove the bowl from the mixer and brush or pour the foam into the mould or baking tray. Close the mould and strap it together if it has more than one piece.
Put the mould or baking tray in the oven when the foam has gelled. If you can poke the foam with your finger without it sticking to the foam, the foam has gelled.
Bake the foam at 82.2 degrees C for 2 to 3 hours for small moulds and baking trays, 3 to 4 hours for large moulds.
Ideally foam latex should be made under room conditions of 20.5 to 22.2 degrees C and 45 to 55 per cent humidity.
Foam latex releases heavy sulphur fumes as it bakes. Do not bake it in your kitchen oven; the odour will affect the taste of food subsequently baked in the oven.