Crystic GT-600 White Isophthalic Polyester Topcoat - BRUSH

Product description and applications

Crystic® GT-600 PAX is a high-performance, pre-accelerated isophthalic polyester topcoat formulated for brush or roller application.

It provides excellent resistance to water and weathering. Its viscosity profile allows a uniform coating to be achieved with minimal sagging and a low-porosity film.

It is particularly suitable as a finishing and protective layer for reinforced polyester laminates in marine, construction, transportation and general composite manufacturing applications.

Features and benefits

• Isophthalic polyester base.
• Excellent resistance to water and blistering.
• Good weather resistance.
• High elongation.
• Good impact resistance.
• Easy application by brush or roller.
• Excellent surface finish.

Brush application

Recommendations

• Before use, ensure that the product has reached a working temperature between 15 °C and 25 °C.
• Add approximately 2% of 50% MEKP or an equivalent catalyst.
• Gently mix the topcoat manually or using a low-speed mixer.
• Apply using long, even strokes while maintaining constant pressure with the brush or roller.
• The recommended application thickness is between 600 and 800 microns.
• The topcoat is intended for use as a final finishing layer over reinforced polyester laminates. It should not be applied to the mould as if it were a gelcoat.

Not recommended

• Do not use high-speed mixers, as they may temporarily reduce the thixotropy of the product and increase sagging.
• Do not apply layers thicker than 800 microns, as excessive thickness may promote air entrapment.
• Do not catalyse more topcoat than can be applied before gelation begins, in order to avoid waste and potentially excessive exothermic reactions.

Additives

The addition of other materials or additives is not recommended, as they may alter the product's application, curing or final performance properties. Consult the Castro Composites technical department before using the product outside the recommended parameters.

Curing

Crystic® GT-600 PAX can achieve a suitable finish when cured at normal workshop temperatures between 15 °C and 25 °C. To obtain the best final properties, the laminate and finishing layer should achieve an adequate degree of cure before being placed into service.

Storage

Store the product in its original, tightly closed container, protected from direct sunlight and under cover. Storage temperatures below 25 °C are recommended and freezing should be avoided.

Storage outside these conditions may alter the product properties and reduce its shelf life. It is recommended that the material be used within 5 months of the date of manufacture.

Health and safety

Consult the Safety Data Sheet before using this product. Unsaturated polyester products may generate heat during curing, particularly when reacting in large quantities.

Type of supply

Crystic® GT-600 PAX White Topcoat x 1 kg, supplied with 20 g of catalyst.

Crystic® GT-600 PAX White Topcoat x 5 kg, supplied with 100 g of catalyst.

Crystic® GT-600 PAX White Topcoat x 18-20 kg, supplied with 0.5 kg of catalyst.