BATHCOTE® HF 99S BASE WHITE

• Provide durable, reduced maintenance products
• Formulated to be resistant to water and certain chemicals

While offering lower VOC’s, BathCote® HF 99S Series gel coats have retained the important construction application qualities customers have come to expect from Polynt Composites gel coats, such as resistance to porosity, tearing, and color separation, sag resistance, consistent liquid properties, good patchability, and more. These all add up to higher quality appeal in FRP parts.

BathCote® HF 99S Series gel coats should be mixed prior to use. Use mixing equipment with sufficient horsepower (relative to container size) to achieve thorough circulation from top to bottom and out to the sides of the container. The agitator must be properly sized for the container and must allow for uniform mixing regardless of the liquid level in the container. Mixing once a day for 10 minutes is typically sufficient. Air bubbling should not be used for mixing. It is not effective and only serves as a potential source of water or oil contamination. Do not overmix BathCote® HF 99S Series gel coats. Overmixing can break down the resin viscosity increasing the tendency to sag.

Although BathCote® HF 99S Series gel coats are formulated as low VOC products, it should be noted that over-atomization of a gel coat means more volatilization (more overspray, more monomer and solids loss, more odor). It is important then to strive for good atomization (good fan pattern, no fingers or tails, uniform particle size of about 1/16) while maintaining lowest pump and atomizing pressures as practical.

Most BathCote® HF 99S Series gel coats are formulated for are formulated for airless as well as conventional spray application. Brushable versions have the word Brushableincluded in the product description and the product code has a B at the end. Refer to Polynt’s Composites Applications Guide for guidelines on brush application.Non-brushable versions are formulated for spray application, but they can be rolled. Brushing these versions is not recommended due to flow and leveling issues. When spraying, the equipment must be well maintained and regularly calibrated. Application procedure recommendations should be followed carefully. Poorly maintained equipment or poor application will quickly negate the beneficial properties of these gel coats. Refer to Polynt’s Composites Applications Guide for equipment and application recommendations.

The inherent chemistry of these gel coats does not allow for the same ease of fluid movement experienced with other gel coats. Adjustments may have to be made for pump pressure, delivery rate, tip size and atomization. Polynt Composites does not recommend fluid lines longer than 50 feet, or pumps smaller than 20:1 ratio. Polynt recommends a gel coat delivery rate of no more than 2.5 pounds per minute with conventional air atomized equipment and no more than 4 pounds per minute with airless equipment.

For best overall end performance properties, a wet film thickness of 18 ± 2 mils is recommended as ideal. Films less than 12 mils may not cure properly, may be hard to patch, have more print-through, and be more susceptible to water blisters. Films above 24 mils may pre-release, trap porosity, crack and are more subject to weathering discoloration.

In addition to the low VOC chemistry, the lower viscosity and thixotropic index result in both less overspray and less monomer loss, but the total film thickness should be sprayed in multiple passes (at least 3 at 18 mils, 4 at 20-24 mils). More rapid film build could result in some sag.

Avoid overspray settling on mold surfaces by beginning the spray pattern closest to the vapor/air exhaust and progressing to the opposite mold end. Maintain recommended spray distances from the mold surface.

Proper mold maintenance is important. Although BathCote® HF 99S Series gel coats have excellent patching properties, minimal repair work is always desirable. Sanding and compounding can hasten the chalking and loss of gloss of all gel coats. BathCote® HF 99S Series gel coats are more sensitive to cold temperatures than are other gel coats.