You may have heard the term 'Jesmonite' lately, if you have been to a craft fair, or any crafty corner of the internet. Jesmonite is a strong, durable, eco-friendly material, which takes many forms, and can be used as a building material, or to make smaller home-decor items. Depending on the type of Jesmonite, it may be used outdoors.
Jesmonite is essentially gypsum powder, mixed with an acrylic binder. It is held to me more eco-friendly than epoxy resin, it has no VOC's, and a shorter supply chain.
Making products from Jesmonite (notably the type AC100), is fast, and fun! If you have ever mixed a cake, it is very similar. Into a clean container goes the wet ingredients (the acrylic liquid binder), and added to that is the dry ingredients, which have been carefully weighed). The ratio is usually 1:4, so one part liquid to 4 parts powder. The two ingredients are thoroughly mixed, often using an electric mixer, so that no lumps remain. The resulting 'batter', can then be coloured, and poured into suitable silicone moulds. It is left to harden for about 30 minutes, and then de-moulded.
After 24 hours, the piece is deemed cured, and is very hard. It is at this point that it can be sanded, and sealed with a waterproof sealant.
If you are a crafter, or someone who likes to make gifts for your home, or for friends and family, then Jesmonite is an excellent, and highly addictive hobby. The short curing time (30 minutes, versus 12-24 hours of epoxy resin), means that it is near instant satisfaction, and if you make a mistake, then you can make another attempt relatively quickly, without the disappointment of having waited for the next day to see the results.
Silicone moulds are available online, just beware that the larger the mould, the more Jesmonite you will need to fill it, and it can get a little expensive! However, it is hugely satisfying to hold in your hand, something that you have just made, and to produce completely individual pieces.
Jesmonite can be customised with different pigments (they are highly concentrated, a little goes a very long way), or with paints, glitters, foils, crushed sea shells...it is definitely worth experimenting..
