Shellspen Suspension Powder – Stable Ceramic Slurry for Lost Wax Casting without Constant Stirring

Suspension powder for a ceramic slurry that does not need continuous stirring

Shellspen suspension powder was developed for ceramic slurries in the lost wax method. You dry-mix the powder through the flour and add it to the binder together with the flour. This keeps the solids in suspension much longer, so periodic mixing according to a fixed schedule is sufficient instead of a continuously rotating tank. One 250 g bag is enough for 25 kg of fused silica flour 325 mesh, i.e. a batch of 25 kg Adbond and 25 kg flour. This yields approximately 27 to 33 litres of slurry.

Main advantages

• No continuously rotating tank: periodic mixing according to schedule is sufficient.
• Stable slurry: the solids stay in suspension longer, so the slurry remains homogeneous.
• Full control: you prepare the slurry yourself from binder, flour and Shellspen.
• Bronze and aluminium: the slurry can be used for both metals.

Typical applications

• ✓ Ceramic shell for the lost wax method
• ✓ Professional users without a continuously rotating slurry tank
• ✓ Bronze and aluminium casting

Processing

1. Take 25 kg of fused silica flour 325 mesh.
2. Dry-mix the entire contents of one bag of Shellspen through the flour.
3. Pour 25 kg of Adbond (approx. 21 litres) into a clean container of at least 40 litres.
4. Add the dry mixture of flour and Shellspen to the Adbond through a sieve while mixing.
5. Mix with a powerful mixer at low speed (maximum 2000 revolutions per minute) until no dry grains remain on the bottom, then continue mixing intensively: at least 4 hours, preferably 24 hours.
6. Let the slurry rest overnight, mix again and sieve the slurry.
7. Check density, viscosity and pH (always above 9.5) and record the values in a logbook.
8. The complete procedure is described in the manual for periodically mixed slurry based on Shellspen (PDF). Read it in full before you start.

Mixing schedule

• ✓ On every day of use: mix for about half an hour before measuring, and always thoroughly just before dipping.
• ✓ During periods without use (weekend, holidays): mix for half an hour at least twice a week. Never leave the slurry unmixed for more than 7 days.
• ✓ How long a prepared slurry remains usable depends entirely on maintenance (mixing schedule, pH, temperature, hygiene). No guarantee is given on the life of a prepared slurry.

Points to note

• ✓ This is a separate formulation with finer flour (325 mesh instead of the usual 120 or 200 mesh), not the same slurry stirred less often.
• ✓ Start on the thin side (1:1). Thicken with flour plus the corresponding Shellspen, thin with Adbond. Do not add water to rescue a thick slurry; only top up evaporated water with demineralised water.
• ✓ Storage: Adbond binder at 5–30 °C, the prepared slurry at 15–25 °C (never below 5 °C or above 30 °C), frost-free and sealed.
• ✓ If you only use part of a bag, homogenise the powder thoroughly first and add a proportional amount.
• ✓ Always rinse degreased models with demineralised water.
• ✓ For aluminium we recommend Clayrac (aluminium silicate) as stucco, as a full fused silica shell can be harder to remove.
• ✓ This product is intended for professional users. An overview of all options can be found on the collection page Ceramic shell materials.

Professional support

Not sure which ceramic shell build-up suits your casting work? Email us at info@siliconesandmore.com and we will be happy to advise you.