POLYCOR® 998 NEUTRAL BASE

1 of 63 products in this brand
Polycor® 998 Neutral Base enamels are formulated to be used as topcoats on fiberglass laminates. Enamels are very similar to gel coats except they cure tack-free on the open surface. Enamels are used to seal and hide a substrate. Normally they are used as interior finishes and yield a pigmented surface. Polycor® 998 series enamels were primarily developed for marine applications; however, they can be used in any FRP application where high performance characteristics are desired. Polycor® 998 series enamels produce a hard, tough, durable coating that reduces maintenance on composites parts. Polycor® 998 series enamels cure to a flat finish. Standard enamels should not be used for water immersion service due to potential water spotting and water blistering. Contact a sales representative for a recommendation if water immersion is required. Polycor® 998 series enamels meet the EPA national emission standards for hazardous air pollutants NESHAP for both marine manufacturing and reinforced composites production. Polycor® 998 series enamels contain wax. The wax is essential to yielding a tack-free surface in the top coating application. The wax also helps to suppress the volatile organic compounds emitted in to the air. Together the low VOC or hap content and wax results in:reduced monomer emissionsless odorsmoother sprayed film less orange peel less overspray due to the wax, Polycor® 998 series enamels should not be used as an in-mold coating where they will be backed by laminate or other materials. Delamination could occur. Enamels require only the addition of the proper amount of the appropriate methyl ethyl ketone peroxide to cure. These enamels are available in White or any of the Colors listed in the standard gel coat color card. Special Colors are available upon request.

Functions: Surface Finish

Color: Custom

Features: Excellent Toughness, High Toughness

Technical Data Sheet
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Identification & Functionality

Composite Materials Functions

Features & Benefits

Labeling Claims
Materials Features

Applications & Uses

Application Method
Recommended Applications

POLYCOR® 998 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® 998 Series Enamels. Overmixing can break down the 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.

Recommended application of enamels is by spraying, but they can be rolled. Brushing is not recommended due to poor flow and leveling. POLYCOR® 998 Series Enamels should be applied 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® 998 Series Enamels. Sand with coarse sandpaper to remove all indications of wax or mold release, then wash with solvent.

If a fleck coat or cob webbing of POLYCOR® enamel is desired over the base coat of enamel, it should be applied while the base coat is wet.

Spray 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 POLYCOR® 998 Series Enamels. Refer to Polynt’s Composites Applications Guide, for equipment and application recommendations. Use the same equipment, settings, and techniques for spraying enamels as used for gel coats.

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 to 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.

Polynt Composites does not recommend fluid lines longer than 50 feet, or pumps smaller than 20:1 ratio. Polynt Composites 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 optimum results, uniform catalyst mix must be achieved. Even with the equipment properly calibrated, potential problems can occur due to poorly atomized catalyst; surging problems (gel coat or catalyst); poor tip alignment (catalyst to gel coat mix); contamination; and poor application procedures, which will quickly negate all benefits of calibration. The equipment (and application procedures) must be monitored on a routine basis to ensure proper application and cure of the gel coat. Inquire about and adhere to all equipment manufacturers’ recommendations.

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.

For best overall 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 are more susceptible to water blisters. Films above 24 mils may trap porosity or crack, and are more subject to weathering discoloration.

One gallon of POLYCOR® 998 Series Enamel will cover approximately 60 to 80 square feet, depending on the film thickness of the coating.

Properties

Color
Typical Properties
ValueUnitsTest Method / Conditions
Gel Time (77°F)10-18minutes
Sag Resistance (77°F)Good at 20 mils
Tack Free/Dull Gloss Time (77°F)60-90minutes
Adhesion Time (77°F)4hr
Flash Point (77°F)82-88°F
Weight per Gallon (77°F)10.0-11.5lbs
Thixotropic Index (2/20) (77°F)4.5-7.0
Hide (77°F)Typically complete at 10 mils (varies with color)
Solvent Wipe Time (77°F)After overnight cure, slight color may be removed but surface will remain tack free
Viscosity Brookfield (RVF, spindle #4 at 20 rpm at 77°F)3400
Viscosity Brookfield (RVF, spindle #4 at 4 rpm at 77°F)15000

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 can also be used, but gel and cure times will vary.

The recommended catalyst range is 1.2% to 3.0% with 1.8% at 77°F being ideal. Normally, POLYCOR® 998 Series Enamels will cure tack free in 60-90 minutes. This time element is dependent on material temperature, room temperature, humidity, air movement, and catalyst concentration. Enamels should NOT be applied when the temperature is below 70°F; inadequate cure can result.

Storage & Handling

Handling and Storage

POLYCOR® 998 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 gel coats (gel time less than 9.0 minutes) are stable for 60 days. The shelf life is cut in half for every 20°F over 73°F.