Knowde Enhanced TDS
Identification & Functionality
- Chemical Family
- Composite Materials Functions
- Technologies
- Product Families
Features & Benefits
- Materials Features
Applications & Uses
- Markets
- Applications
- Application Method
- Recommended Applications
ARMORCOTE® 991 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 types used, the equipment must have sufficient horsepower (relative to container sixe) to achieve thorough circulation from top to bottom and out to the sides of the container. The agitator must be properly sixed 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 ARMORCOTE® 991 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.
Although products in the ARMORCOTE® 991 Series are formulated as MACT compliant products, it should be noted that over-atomization of a gel coat results in more volatilization (more overspray, more monomer and solids loss, more odor). It is important therefore 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.
ARMORCOTE® 991 Series gel coats can be applied with air-atomized or airless equipment. Brushing or rolling is not recommended. Refer to Polynt’s Composites Applications Guide, Part Four, Chapter 11.3, Conventional Gel Coat – Spray equipment for equipment recommendations. For best results these high performance coatings require careful application procedures. Poor application will quickly negate the beneficial properties of these gal coats. Refer to Polynt’s Composites Applications Guide, part Four, Chapter 11.4, Conventional Gel Coat – Application.
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 (ARMORCOTE® or catalyst), poor tip alignment (catalyst to ARMORCOTE® 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. Ask about and adhere to all equipment manufacturers’ recommendations.
A delivery rate of no more than 2.5 pounds per minute with conventional air-atomized equipment and no less than 60 psi atomizing air (dynamic) at the gun is essential. Use no more than 4 pounds per minute with airless equipment. High flow rates cannot be properly achieved using air-assist airless equipment. Attempts to use flow rates over 3 pounds per minute may result in poor application. These products require a closer control of application procedure than higher VOC gel coats.
Products in the ARMORCOTE® 991 Series are lower in viscosity and are easier to pump and spray. Slightly lower pumping pressures and atomizing air pressures are normally required than are necessary for regular gel coats, and other low VOC gel coats.
Properties
- Color
- Typical Properties
| Value | Units | Test Method / Conditions | |
| Flash Point (77°F) | 79 | °F | — |
| Viscosity (77°F) | 13,000-19,000 | cps | — |
| Thixotropic Index (77°F) | 4.5-7.0 | — | — |
| Weight per Gallon (pigmented) (77°F) | 11.3 (white) | — | — |
| Gel Time (77°F) | 10-18 | minutes | — |
| Lay-up Time (77°F) | 45-90 | minutes | — |
| Sag Resistance (77°F) | 24 mils wet | — | — |
| Hide (Most Formulations) (77°F) | Complete at 10 mils wet | — | — |
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 catalyst level should not exceed 3% or fall below 1.2% for proper cure. Recommended range is 1.2% to 3.0% with 1.8% at 77°F being ideal. Normally, the film is ready for lamination in 45 to 90 minutes. This time element is dependent on material temperature, room temperature, humidity, air movement, and catalyst concentration.
This product should not be used when mold and ambient temperature conditions are below 60°F, as curing may be adversely affected. Material temperature should be at least 70°F.
Storage & Handling
- Handling and Storage
Uncatalyzed, standard cure ARMORCOTE® has 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. Totes of product can have even shorter shelf life – 66% of that for drums.