Sandability
The softness of pure talc leads to good sandability of polyester putties. Pure, flotated Finntalcs, which are free of abrasive accessory minerals such as chlorite or quartz have proven to be the best choice.
However, in some applications a harder putty may be required, in these cases magnesite-bearing talcs like Micro-talc AT200-KN are recommended.
Low and consistent oil absorption
The flotation process of Finntalcs leads to a product with very consistent chemical and physical properties. By double air classification, the fine dust is removed, resulting in talc products with low oil absorption. These unique combination of properties has made Finntalc M40 and Finntalc M50 the most popular products for polyester putties.
Adhesion and elasticity
The highest elasticity is achieved with talcs of low oil absorption, at the same time lamellarity increases the adhesion on steel substrate.
Pot life
The pot life is adversely affected by the content of soluble contaminants. Finntalc M40 shows the least content of HCl solubles, and leads to the longest pot life.
Viscosity anf filling level
Viscosity and filling level depend on surface area and structure of the talc particles. Macrocrystalline, coarse, double-classified talcs like Finntalc M50 allow the highest filling level.
