Knowde Enhanced TDS
Identification & Functionality
- Composite Materials Functions
- Technologies
- Product Families
Features & Benefits
- Materials Features
- Product Highlights
- Cure tack-free
- Can be used like paint – a topcoat to seal and hide a substrate
- Produce a hard, tough, durable, flat finish
- Good water resistance characteristics
- Reduced VOC emissions
Enamels cannot be used as gel coats because they contain wax and cure tack-free, thus delamination and pre-release could result. But, in addition to providing a tack-free surface, the wax helps to suppress styrene, which reduces the volatile organic compounds emitted into the air. Standard enamels should not be used for water immersion service.
Applications & Uses
- Markets
- Recommended Applications
POLYCOR® 948 Series enamels 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 POLYCOR® 948 Series enamels. Overmixing can break down the resin viscosity increasing the tendency to sag.
POLYCOR® 948 Series enamels should be sprayed after the laminate has cured and while it still has a tacky surface. Glossy/resin rich laminates may cause the enamel to separate, sag, and have poor adhesion. Ensure that glossy areas are well sanded, then blow off the area and clean with solvent.
Laminates containing a wax surfaceor mold releaseshould be sanded before coating with POLYCOR® 948 Series enamel. Sand with rough sandpaper to remove all indications of wax or mold release, and then wash with solvent.
If a fleck coat or cobwebbing of POLYCOR® 948 Series enamel is desired over the base coat of enamel, it should be applied while the base coat is wet.
Most POLYCOR® 948 Series enamels are formulated for 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 enamels. Refer to Polynt’s Composites Applications Guide for equipment and application recommendations.
Polynt Composites does not recommend fluid lines longer than 50 feet or pumps smaller than 20:1 ratio. Polynt Composites recommends an enamel 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.
When establishing the fan pattern for the spray equipment, use the lowest pump pressure needed to achieve a good fan pattern (no fingers or tails, uniform particle size of about 1/16²). Use of higher pressures can lead to a porosity or excessive overspray. Overspray can result in a leathery or chicken skin texture if it falls on the part surface. To minimize overspray that falls onto the mold, plan the spray pattern so that the beginning is closest to the vapor/air exhaust and progresses to the opposite mold end. The spray pattern should also allow for a wet line to be maintained.
A spray distance of 18-36 inches is recommended. Closer spray distances can result in blowing of the film or air entrapment. Spraying at distances greater than 4 feet will increase orange peel and porosity. For deep channels, recessed, and hard-to-spray areas, an extension nozzle is highly recommended.
For best overall end performance properties, a wet film thickness of 16-20 mils is recommended. The film should be applied in multiple passes with each pass having a thickness of 5-8 mils. More rapid film build could result in some sag and porosity. 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 prerelease, trap porosity, crack and are more subject to weathering discoloration.
One gallon of POLYCOR® 948 Series enamel will cover approximately 60-80 square feet, depending on the film thickness of the coating.
Properties
- Color
- Typical Properties
| Value | Units | Test Method / Conditions | |
| Viscosity (77°F) | 15,000-21,000 | cps | — |
| Thixotropic Index (77°F) | 5.5-7.5 | — | — |
| Gel Time (77°F) | 10-17 | minutes | — |
| Tack Free/Dull Gloss Time (77°F) | 60-90 | minutes | — |
| Adhesion Time (77°F) | 4 | hr | — |
| Sag Resistance (77°F) | Good @ 20 mils | — | — |
| Hide (77°F) | Generally complete at 10 mils | — | — |
| Weight per Gallon (77°F) | 10.5-11.0 | lbs/gal | — |
| Solvent Wipe Time (77°F) | After overnight cure, slight color may be removed but surface will remain tack-free | — | — |
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 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, NOROX® MEKP-925 and NOROX® MEKP-925H, and Pergan HP®-90 may yield slightly shorter gel and cure times.
The recommended catalyst range is 1.2-3.0%, with 1.8% at 77°F being ideal. Cure characteristics are dependent on material temperature, room temperature, humidity, air movement, and catalyst concentration. Special fast cure versions are available but must be requested.
These products offer lay-up times of less than 45 minutes. Fast cure products have shorter stability and should not be inventoried over 45 days. Enamels (whether standard or fast cure) should not be used when temperature conditions are below 70°F, as curing may be adversely affected.
Storage & Handling
- Handling and Storage
Uncatalyzed, POLYCOR® 948 Series enamels 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 enamels (gel time less than 9.0 minutes) have a shelf life of 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.