These are the most frequently asked questions about Jesmonite, we hope these FAQs will help and support you in your Jesmonite journey. General questions are below in the accordion. Specific product questions are tagged.
All Jesmonite products including Jesmonite AC100 are classed as porous and would need to be sealed with a top coat sealer to achieve a waterproof surface.
Jesmonite AC100 is an Acrylic Modified Gypsum Composite compared to Jesmonite AC730 which is an Acrylic Modified Cementitious Composite. Jesmonite AC100 contains gypsum and is designed to replicate very fine surface detail and Jesmonite AC730 contains decorative aggregates and is designed to replicate concrete and stone surfaces.
Here at Jesmonite we sell our products through a Distribution network, please find and contact your nearest official Jesmonite distributor here to place an order. Jesmonite distributors
We recommend demoulding AC100 after 2 hours, we then suggest you leave your creation to fully cure for 24 hours before sanding or sealing.
We wouldn’t recommend placing Jesmonite products within a kiln or above
We have not yet come across burn-proof sealers, there may be something viable on the market, but they would need to investigate further and run their own tests.
How to make a Jesmonite candle - https://www.youtube.com/shorts/0-Aom4ABHaY
To bond cured Jesmonite materials you would need to investigate either an epoxy based adhesive or PU based adhesive. Most of our clients find that the 2 pack epoxy adhesives are stronger than the 1 pack adhesives.
Jesmonite products can be pigmented to any colour reference. Jesmonite can also mimic any texture and reproduce the effect of materials such as stone, metal, wood, leather and fabric.
High grade silicone moulds are predominantly used in conjunction with Jesmonite products due to the silicone offering high levels of flexibility whilst achieving increased ease of de-mould and fine detail replication. Rigid mould compounds including plaster, Jesmonite, GRP, metal, wood, and glass can be used in conjunction with Jesmonite products, however the mould surface would require a release wax/agent to be applied to assist the de-mould of cured Jesmonite products.
All Jesmonite products can be pigmented to any colour required when used in conjunction with the Jesmonite Liquid Pigments. Please be aware that the Jesmonite Liquid Pigments are not fully UV stable and are not designed for external use, we recommend you use them for internal projects only.
The Jesmonite Liquid Pigments are intermixable and can be mixed together to create any colour required. Pigments must be added to Jesmonite Liquids by weight before the Base is added and mixing commences. Pigments are added at 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.
Jesmonite pigments in use - https://www.youtube.com/shorts/gNRnJN3XMzs
The most appropriate Jesmonite sealer for home ornaments would be Jesmonite Acrylic Sealer. Jesmonite Acrylic Sealer is a pure acrylic coating. It is durable, flexible, and UV resistant.
All your sealer questions answered here - https://www.youtube.com/watch?v=dhM-1dj0XU8
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
To clean the moulds after use, rinse with warm soapy water, and dry thoroughly before using again.
To remove air bubbles on the Jesmonite material surface we would always recommend you brush a 1-2mm first layer of mixture into the mould first, before backing up with further Jesmonite material. The brushing technique will push out and remove air bubbles. You can also vibrate the first layer of the mixture to help the air escape from the surface. Watch this YouTube video for all the tips and tricks for eliminating air bubbles - https://www.youtube.com/watch?v=SFYyF3EU5a4
It is not advised to use Jesmonite in either of these.
Jesmonite products can be broken down into two categories; Acrylic Modified Gypsum Composites and Acrylic Modified Cementitious Composites (PGRC)
Jesmonite materials are non-solvent and contain zero VOCs, however, please be aware that we have not tested any Jesmonite products for food safety.
Jesmonite material solutions can be used for decorative tableware; however, we would not recommend you place food or liquids onto the finished Jesmonite products.
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.
All Jesmonite products are water-based, non-solvent and contain no VOC's.
Jesmonite products are supplied as a 2 pack kit, containing a reactive mineral base and a pure water based acrylic liquid. To mix the two compounds together you will require a Jesmonite High-shear Mixing Blade. High-shear Mixing Blades are essential for the proper mixing of all Jesmonite composite materials. They are specifically designed for adding Jesmonite Base into Jesmonite Liquids. 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
Jesmonite products are composite materials, a combination of a reactive mineral base and a pure water based acrylic resin.
For casting Jesmonite AC730, every 1,000ml of mould volume will require 1,850g of complete mixed Jesmonite AC730 (1,850g Jesmonite AC730= 1000ml).
You can use this Jesmonite Calculator by RazzoStudio.
Jesmonite AC730 cured surfaces can be sanded using a variety of sandpaper grades to reveal decorative aggregates and achieve a range of different surface appearances and textures. Most users will start with a coarse sandpaper and then move onto a fine sandpaper grade for finer finishing. The sanding process can be done by hand or with a power sander.
The most appropriate Jesmonite material for a decorative splash is Jesmonite AC730. Jesmonite AC730 achieves an A2-s1-d0 EN13501-1 (non-combustible) Fire Classification.
Jesmonite Flexiguard Sealer is the most appropriate Jesmonite sealer for Jesmonite AC730 surfaces. The Jesmonite Flexiguard Sealer is a solvent-free, nano based technology. This sealer is designed for stain resistance and offers an invisible surface effect. The Jesmonite Flexiguard Sealer achieves a protective layer less than 100-nm thick which bonds with the inner pores of the AC730 substrate.
Jesmonite AC730 can be used for water features and within wet environments.
For casting Jesmonite AC100, every 1,000ml of mould volume will require 1,750g of complete mixed Jesmonite AC100 (1,750g Jesmonite AC100 = 1000ml).
You can use the Jesmonite calculator by RazzoStudio.
Jesmonite AC100 cured surfaces can be sanded using a variety of sandpaper grades to achieve a range of different surface appearances and textures. Most users will start with a coarse sandpaper and then move onto a fine sandpaper grade for finer finishing. The sanding process can be done by hand or with a power sander.
No. The products are sold as a composite and designed specifically to work together. Jesmonite do not test the liquids with other powders.
The Jesmonite Thixotrope is added to the Jesmonite AC100 mix to thicken the material to a ‘gel-coat’ consistency. This is useful when brushing or spraying materials onto moulds with vertical faces as it prevents the material from slumping. Jesmonite Thixotrope is added to the complete Jesmonite AC100 mixture and is mixed in using the Jesmonite High-Shear Mixing Blade. Add drop by drop until the desired consistency is achieved. Typical inclusion rates by weight are 2g–6g per kg (0.2-0.6%) of complete Jesmonite AC100 mix.
Jesmonite Acrylic Sealer is the most appropriate sealer for Jesmonite AC100 surfaces. The Jesmonite Acrylic Sealer is a pure acrylic coating. We recommend applying the Jesmonite Acrylic Sealer onto Jesmonite AC100 surface with a dense foam roller rather than low density foam and traditional paint rollers. The low density foam and traditional paint rollers can leave streaks where the Jesmonite Acrylic Sealer builds up unevenly on the ends of the rollers.
The setting time can be anything between 50 minutes and 2 hours, depending on temperature in the room.
Jesmonite AC100 would be best suited for lightweight jewellery.
Jesmonite AC630 cured surfaces can be sanded using a variety of sandpaper grades to achieve a range of different surface appearances and textures. Most users will start with a coarse sandpaper and then move onto a fine sandpaper grade for finer finishing. The sanding process can be done by hand or with a power sander.
Jesmonite AC630 is formulated to result in a smooth concrete/stone or exposed concrete/stone surface finish.
It is possible to create Jesmonite AC630 decorative coasters, bowls, plates, soap dishes and trays.
Jesmonite AC630 can be used for water features and offers enhanced durability within wet conditions.
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