Knowde Enhanced TDS
Identification & Functionality
- Composite Materials Functions
- Technologies
- Product Families
Features & Benefits
- Labeling Claims
- Product Highlights
- Easy to spray
- Resistant to porosity, pinholing, tearing, and color separation
- Easy to sand when cured
- Low volatile organic compound properties
- Reduced monomer losses into the air; less overspray
- Cured film thickness can be 5-7% more than other gel coats
- Less odor They are ready to use and require only the addition of the proper amount of an appropriate peroxide to cure.
Applications & Uses
- Markets
- Recommended Applications
POLYCOR® 969 Series sanding gel coats must be mixed prior to use. This includes prior to production spray application and when obtaining material for patching or any material that has been set aside for patching. Several suitable types of mixing equipment and styles of agitators are available for both pails and drums. Regardless of the specific type used, the equipment must have 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. Do not overmix POLYCOR® 969 Series sanding gel coats. Overmixing can break down the polymer coating viscosity increasing the tendency to sag. Overmixing can also result in styrene loss which could contribute to porosity. Air bubbling should not be used for mixing. It is not effective and only serves as a potential source of water or oil contamination.
These products are formulated for airless, air-assist airless and conventional spray application. Neither brushing nor rolling is recommended. 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 or air-assist airless equipment.
For the best 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, and will have more print-through. Films above 24 mils may pre-release, trap porosity, and crack more easily.
Although POLYCOR® 969 Series sanding 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 inch) while maintaining lowest pump and atomizing pressures as practical.
The inherent chemistry of low VOC 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. In addition, 969 Series sanding gel coats are more sensitive to cold temperatures than are other gel coats.
For RTM, molds above 100°F require a high temperature mold release. The mold type and temperature will affect mold release selection. See mold release data sheets for proper selection. Note: Mold release transfer can affect paintability and must be evaluated with the final paint system.
Mold release agent(s) must be properly wiped off the mold before spraying gel coat. Residual mold release will cause wax spews when parts are sanded and baked. Parts should be washed, scuff-sanded to remove all gloss, and washed again with a suitable solvent. This should remove any mold release transfer and provide for mechanical adhesion of paint systems. Note: Parts should be inspected just before painting because they can pick up moisture and other contaminates if not properly stored.
Properties
- Color
- Typical Properties
| Value | Units | Test Method / Conditions | |
| Sag Resistance at 77°F (Good) | 20 | mils | — |
| Viscosity Brookfield RVF #4 Spindle at 4 rpm at 77°F | 15,000-20,000 | cps | — |
| Thixotropic Index 00D_(2/20 rpm) at 77°F | 5.5-7.0 | — | — |
| Gel Time 100 g mass, 1.8% Arkema at 77°F | 44090 | minutes | — |
| Weight per Gallon at 77°F | 11.3-12.0 | lbs | — |
| Lay-up Time at 77°F | 60-75 | minutes | — |
| Hide | 10 | mils | — |
Technical Details & Test Data
- Cure
It is recommended that gel time be checked in the customer's plant because age, temperature, humidity and catalyst will produce varied gel times. All data referencing gel or cure refers specifically to Arkema Luperox® DDM-9 or United Initiators Norox ® MEKP-9H catalyst. United Initiators Norox® MEKP-9 and Norox® MEKP-9H, Akzo Nobel Cadox® L-50a and Cadox® D-50 are expected to yield similar performance. Arkema Luperox® DHD-9, United Initiators Norox® MEKP-925 and Norox® MEKP-925H, and Pergan HP-90 may yield slightly shorter gel and cure times.
These products should not be used when temperature conditions are below 60°F, as curing may be adversely affected.
Storage & Handling
- Handling and Storage
Uncatalyzed, standard cure gel coats have a shelf life of 120 days from date of manufacture when stored at 73°F or below, in a closed, factory-sealed, opaque container, and out of direct sunlight. Fast cure gel coats (gel time less than 9.0 minutes) are stable for 60 days. Shelf life is cut in half for every 20°F over 73°F. Totes of product can have even shorter shelf life – 66% of that for drums.