Knowde Enhanced TDS
Identification & Functionality
- Composite Materials Functions
- Technologies
- Product Families
Features & Benefits
- Product Highlights
- Easy to spray as a regular isophtalic gelcoat
- Only requires the addition of the proper amount of MEKP catalyst
- Wide range of color and also customer color-matching available on request
Applications & Uses
- Markets
- Applications
- Recommended Applications
255X series gelcoats are generally formulated for both airless and conventional spray applications. Neither brushing nor rolling is recommended. Refer to PB-16 (application Guide) and PB-3 (Equipment selection) bulletins for additional specific recommendations. Polynt Composites recommends a gelcoat 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.
Batch mixing is recommended to achieve the best catalyst mix and cure because even with the equipment properly calibrated, potential problems can occur due to: poorly atomized catalyst; surging problems (gelcoat or catalyst); poor tip alignment (Catalyst to gelcoat 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 gelcoat. Ask about and adhere to all equipment manufacturer’s recommendations.Avoid over-spray settling on mold surfaces by beginning 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, have more printtrough, 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-trough and blistering could suffer.
Proper mold maintenance is important. Although Polynt Composites 255X series gelcoats have good patching properties, minimal repair work is always desirable. Sanding and compounding can hasten the chalking and loss of gloss of all gelcoats.
Properties
- Color
- Typical Properties
| Value | Units | Test Method / Conditions | |
| Specific Gravity (25°C) | 1.27 - 1.32 | kg/l | — |
| Viscosity Brookfield RVF rotor #4 at 4 rpm at 25°C or 77ºF Colored | 11,000 - 16,000 | cPs | — |
| Viscosity Brookfield RVF rotor #4 at 4 rpm at 25°C or 77ºF White and off white | 15,000 - 20,000 | cPs | — |
| Thix Index (2/20) at 25°C or 77ºF | min. 5.5 | — | — |
| Gel Time at 1.8% MEKP925 at 25°C or 77ºF | 7 - 17 | minutes | — |
| Tack freeat 25°C or 77ºF | 45 - 60 | minutes | — |
| Sagging resistance Good at 25°C or 77ºF | 20 | mils | — |
| Opacity (most formulation) Complete at 25°C or 77ºF | 12 | 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 UNITED INITIATORS MEKP 925 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. NOROX MEKP-925H,and Witco HP-90 may yield slightly shorter gel and cure times.
The catalyst level should not exceed 3.0% 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 gelcoat film is ready for lamination in 60 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 temperature conditions are below 60°F, as curing may be adversely affected.
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 gelcoats have a usage life of 45 days from date of manufacture when stored at 73°F or below in a closed, factory-sealed opaque container and out of direct sunlight. The usage life is cut in half for every 20°F over 73°F.