Knowde Enhanced TDS
Identification & Functionality
- Composite Materials Functions
- Technologies
- Product Families
Features & Benefits
- Materials Features
Applications & Uses
- Markets
- Recommended Applications
21X series gelcoats are generally formulated for brushing & rolling applications.
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, have more print-through, and are more susceptible to water blisters. Films above 24 mils may pre-release, trap porosity, or crack, and are more subject to weathering discoloration. If water blisters are of a great concern (boat hulls), 20 to 24 mils would perform better than a thinner film, but resistance to sag, porosity and cracking could suffer. If weathering (yellowing from sunlight, decks) is of great concern, then thinner films (12 to 16 mils) would perform better, but patchability and resistance to print-through and blistering could suffer.
Proper mold maintenance is important. Although 21's 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
Properties
- Color
- Typical Properties
| Value | Units | Test Method / Conditions | |
| Viscosity Brookfield RVF #4 Spindle at 20 rpm | 9000 - 15000 | cps | — |
| Thixotropic Index (2/20) | min. 4 | — | — |
| Gel Time at 1.8% MEKP** | 8-17 | minutes | — |
| Lay-up Time | 45 - 60 | minutes | — |
| Sag Resistance | Good at 20 mils | — | — |
| Hide (Most Formulations) | Complete at 12 mils. | — | — |
| Weight per Gallon | 1,20 - 1,35 | Kg/liter | — |
| Flash Point (82 - 88°F) | 27,8 - 31,1 | °C | — |
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 NOROX MEKP-925 catalyst.
The catalyst level should not exceed 3.0% or fall below 1.2% for proper cure. Recommended range is 1.8% at 77°F being ideal. Normally, the gel coat film is ready for lamination in 45 to 60 minutes. This time element is dependent on material temperature, room temperature, humidity, air movement, and catalyst concentration.
This product should not be used when temperature conditions are below 60°F, as curing may be adversely affected.
Safety & Health
- Product Safety
Isophthalic gel coats are not compatible in the liquid state with ISO/NPG gel coats or ISO/NPG resins. Equipments must be completely clean of these gel coats or resins before isophthalic’s can be used. Do not over-mix gel coats. Over-mixing breaks down gel coat viscosity, increasing tendencies to sag, and causes styrene loss, which could contribute to porosity. Gel coats should be mixed once a day for 10 minutes. The gel coat should be mixing to the sides and bottom of the container with the least amount of turbulence possible. Air bubbling should not be used for mixing. It is not effective and only serves as a potential for water or oil contamination. Do not add any material, other than a recommended methyl ethyl ketone peroxide, to this product without the advice of a representative of Polynt Composites.
Packaging & Availability
- Packaging Type
- Product Availability
Shipment is normally in open head, 55-gallon drums (204 liters) or 4,4 imperial gallons (20 liters)
Storage & Handling
- Handling and Storage
Uncatalyzed, standard cure gel coats have a usage life of 90 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 are stable for 30 days.