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Jesmonite is made by Jesmonite Limited in the UK and shipped around the world. It is a composite material which combines a reactive mineral base and a water-based acrylic resin.
Jesmonite products are used within a wide range of decorative markets including craft, tableware, artwork, sculpture, lighting, furniture, marine vessels, film sets, architectural elements and cladding panels.
Liquid containers should be kept well sealed to prevent water evaporation and skin forming. They should be stored at a constant temperature between 5°C– 25°C and used within six months. Freezing must be avoided. Base powder should be kept dry and stored at 5°C – 25°C.
To properly mix Jesmonite liquid and powder together you will need a Jesmonite High-shear Mixing Blade, which is specifically designed for mixing Jesmonite. The mixing action reduces air bubbles and ensures that the mix is smooth and free from lumps. Two sizes are available, 65mm and 105mm for different mix sizes. They are made from stainless steel, and will attach to all conventional drills.
All Jesmonite products are water based, non-solvent and contain no VOCs.
Jesmonite is non-solvent and contains zero VOCs, however, it has not been tested for food safety.
It is not advised to use Jesmonite in a dishwasher or microwave.
Jesmonite products have been tested in accordance with EN 13501-1 under the harmonised Euroclass System of reaction to fire performance of building products which has been adopted by countries across Europe.
To clean the moulds after use, rinse with warm soapy water, and dry thoroughly before using again. For the best possible clean we recommend Grimex wipes – they are great for removing every trace of dirt and dust.
We recommend Jesmonite Acrylic Sealer, which is a durable, flexible, and UV resistant pure acrylic coating.
Jesmonite can be pigmented to any colour required using Jesmonite Pigments.
Pigments should be added to a maximum of 2% by weight of the total mix, or 20grams/kilo of total mix (Base and Liquids). 20 grams will produce a strong, saturated colour. For lighter colours simply reduce the addition rate until the desired colour is achieved.
Starter kits are packaged and sealed by the Jesmonite factory and will contain a selection of 3 pigments.
Jesmonite can mimic nearly any texture and reproduce the effect of materials such as stone, metal, wood, leather and fabric.
To bond cured Jesmonite you will need to either an epoxy or PU based adhesive. Most of our customers find that 2-pack epoxy adhesives adhere better than 1-pack adhesives.
No. We recommend exploring using a burn-proof sealer.
Buying from unapproved distributors is risky, as Jesmonite has a shelf-life and it’s impossible to know how long the original containers have been open for. We always recommend buying from an approved distributor, like Polysil.
You can reduce the bubbles in your Jesmonite work in a few ways:
1. Make sure your mix is made to the correct ratio.
2. Blend your mix for a minimum of 2 minutes using a Jesmonite mixing blade (attached to a drill).
3. Brush a 1-2mm coat of Jesmonite onto the mould (make sure your brush is clean and dry.)
4. Vibrate and tap the mould to bring air bubbles to the surface.
5. Fill the rest of the mould and repeat tapping. This is easiest if you don’t overfill your mould!
6. Pop air bubbles by blowing.
Top Tip: Use a straw to direct your breath better!
Silicone Rubber FAQs
Polysil sell RTV Silicone Rubber F23 and Silicone Rubber (Genuine 3841). Both have similar properties with excellent fluidity, low shrinkage, good strength and easy demoulding. The 3481 has some advantages that are more suited to the professional user:
– The material is German made using only the finest raw ingredients.
– Mechanical properties such as tear strength and elongation to break are superior.
– Proven archive life (i.e. The rubber can be stored for future use and will retain strength and elasticity.)
We stock two different types of 3481, one can be used with a Thixo additive.
No. There are currently no distributors in the US.