Aluminium Powder — Cold Cast and Metallic Finish Grades

Primary uses

• Metallic silver appearance
• Cold-cast aluminium surfaces
• Gas generation in aerated systems where specified

Applications

• Cold-cast aluminium and metallic resin castings
• Metallic coatings and effect finishes
• Aerated concrete production where the grade is intended for it
• Decorative and industrial finishes

Advantages

• Produces a bright metallic silver surface on resin castings that pigment alone cannot imitate
• Polishes and finishes using metal-finishing techniques for a genuine metal appearance
• Lighter and cheaper than casting the equivalent piece in metal

Limitations to consider

• Fine aluminium powder carries dust explosion and reactivity hazards that require specific handling controls
• Reacts with water and with some chemistries, so storage and mixing discipline matter
• Particle size, metal content and finishing behaviour are declared by the supplier for the exact powder
• Decorative and architectural work is judged by eye. Colour, gloss, texture and translucency shift with batch, substrate, dosage and finishing method, so approve a physical sample panel made by your own process before a production run and keep it as the reference for later deliveries.
• Mix ratio, pot life, working time, demould time, full-cure schedule, hardness, tear strength, elongation, shrinkage, viscosity and temperature resistance are properties of one specific supplier system. They are never quoted here from memory or by analogy with a similar product; they are read from the supplier data sheet for the exact material offered and confirmed at quotation.

How to choose the right grade

• Start from the matrix — cementitious, resin or coating — because alkali stability and dispersion behaviour are decided by it
• Agree the colour standard and how it will be verified between deliveries, since colour is the whole point of the purchase
• State the exposure the finished surface will see, including UV, weather and de-icing salt in Canadian service
• Confirm the plant's dust handling and ignition control arrangements before the first delivery
• Trial the face coat loading and polishing process on a sample piece
• Mould-making and casting behaviour depends on the pattern, the shop temperature and humidity, the mixing method and the operator. A production-representative trial on your own pattern and in your own shop conditions is the only honest way to qualify a material before a run is committed.
• Exact specification is confirmed against supplier documentation at quotation.

Typical grades

• Particle sizes and forms as the supplier classifies them
• Products intended for cold-cast and decorative work as designated by the supplier
• Buyers search this category by grade name, and those names describe what the workshop needs rather than what is asserted here. Which grade a specific offer corresponds to, and what the supplier declares for it, is read from the technical documentation issued for the exact material quoted.
• Materials in this category interact: rubbers, releases, sealers, resins, pigments and fillers can inhibit cure, stain a surface or shorten mould life when they are combined outside the combinations the supplier has tested. State every material already in the process at enquiry so compatibility is checked against supplier documentation rather than discovered on the shop floor.
• Reactive materials age in the container, and moisture-sensitive systems age faster once opened. Order against real consumption rather than against a discount, and confirm the shelf life the supplier states for the exact product and pack.