Jesmonite Knowledge Hub

About Jesmonite

What are Jesmonite products made from?

Jesmonite products are composite materials, a combination of a reactive mineral base and a pure water based acrylic resin.

How should I store Jesmonite Base and Liquid?

As a basic rule 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 should be kept dry and stored at 5°C – 25°C.

How do I mix Jesmonite materials?

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.

Are Jesmonite products safe?

All Jesmonite products are water-based, non-solvent and contain no VOC’s.

Are Jesmonite products fire rated?

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.

Is Jesmonite food safe or is there a finish to make Jesmonite food safe?

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.

What type products do Jesmonite offer?

Jesmonite products can be broken down into two categories; Acrylic Modified Gypsum Composites and Acrylic Modified Cementitious Composites (PGRC).

Is Jesmonite dishwasher/microwave safe?

It is not advised to use Jesmonite in either of these.

Is Jesmonite waterproof?

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.

Get Creative with Jesmonite

How do I wash the moulds?

To clean the moulds after use, rinse with warm soapy water, and dry thoroughly before using again.

How can I get rid of bubbles in Jesmonite?

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 / poking (tip: use a toothpick).

Which type of markets are Jesmonite products used for?

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.

How do I colour my Jesmonite?

Jesmonite can be pigmented to any colour required using Jesmonite Pigments.

What type of moulds can be used in conjunction with Jesmonite products?

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.

What type of colours and textures can be achieved with Jesmonite products?

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.

Can you place Jesmonite products in a kiln?

We wouldn’t recommend placing Jesmonite products within a kiln or above 80 °C.

AC100

How do I work out how much Jesmonite AC100 material I need?

For casting Jesmonite AC100, every 1,000ml of mould volume will require 1,750g of complete mixed Jesmonite AC100 (1,750g Jesmonite AC100 = 1000ml).

What is the set time of Jesmonite AC100?

We recommend demoulding AC100 after 2 hours, we then suggest you leave your creation to fully cure for 24 hours before sanding or sealing.

Can you sand Jesmonite AC100?

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. See our Sandpaper/ Sponge collection.

What is the most appropriate Jesmonite sealer for Jesmonite AC100 surfaces?

Jesmonite Acrylic Sealeris 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.

Which Jesmonite product is recommended to make lightweight jewellery?

Jesmonite AC100 would be best suited for lightweight jewellery.

What is the setting time of AC100 starter kit?

The setting time can be anything between 50 minutes and 2 hours, depending on temperature in the room. See AC100 starter kit.

Is it possible to use marble powder instead of part 2 of the Jesmonite AC100?

No. The products are sold as a composite and designed specifically to work together. Jesmonite do not test the liquids with other powders.

Is there a way to use the Thixotropic to allow for vertical modelling?

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.

AC730

How do I work out how much Jesmonite AC730 material I need?

For casting Jesmonite AC730, every 1,000ml of mould volume will require 1,850g of complete mixed Jesmonite AC730 (1,850g Jesmonite AC730= 1000ml).

Can you sand Jesmonite AC730?

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.

Can Jesmonite AC730 be used for a water feature?

Jesmonite AC730 can be used for water features and within wet environments.

What is the most appropriate Jesmonite sealer for Jesmonite AC730 surfaces?

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.

Is Jesmonite safe to use as a splashback behind a gas hob?

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.

×