Dow A-4040 Prime Coat
Application Type Primer Coat 1 Part or 2 Part 1-Part Material Form Liquid Substrate Ceramics, Fabrics, Glass, Metals, Silicone Manufacturer Dow Chemistry Naphtha Cure Method Solvent, Moisture Cure Temperature (°C) 20 to 25 Cure Time (min) 60 to 120 Color Clear, Light straw
Technical Data for Dow A-4040 Prime Coat
- Coating - Primer Coat
1 Part or 2 Part
- Other - Naphtha
- Brush - Wiping
- Moisture / Condensation Cure - Moisture
- Clear / Transparent - Clear
- Yellow - Light straw
Cure Temperature (°C) 20 to 25 Cure Time (min) 60 to 120
Flash Point (°F) 46.4 Test Method
Shelf Life Details Shelf life is indicated by the “Use Before” date found on the product label. For best results, Dow Corning primers, prime coats and adhesion promoters should be stored below 32°C (90°F). Special precautions must be taken to prevent moisture from contacting these materials before use. Containers should be kept tightly closed and head or air space minimized. Partially filled containers should be purged with dry air or other gases such as nitrogen to maximize shelf life. Small amounts for immediate use should be poured into clean, dry containers and discarded when finished. Material should not be used once it takes on a milky appearance or a large amount of white precipitate is observed, indicating moisture contamination. Repeated opening of the container can cause a small amount of white precipitate to form inside the container cap area, which does not affect the bulk material. Shelf Life Temperature (°F) <90 Shelf Life Type from date of manufacture Shelf Life (mon) 24
Best Practices for Dow A-4040 Prime Coat
The active ingredients must thoroughly wet-out and coat the bonding surfaces. Mild abrasion, solvent cleaning, plasma, corona discharge and other pre-treatments have been used to clean and enhance surface reactivity to bonding. In general, light surface abrasion is recommended whenever possible, because it promotes good cleaning and increases the surface area for bonding. Surfaces should be cleaned and/or degreased with Dow Corning ® brand OS Fluids, naphtha, mineral spirits, methyl ethyl ketone (MEK) or other suitable solvents that will remove oils and other contaminants that may be present. A final surface wipe with acetone or IPA may also be helpful. Different cleaning techniques may give better results than others. Users should determine the best technique for their applications.
These products should be applied in a very light, even coat by wiping, dipping or spraying. Excess material should be wiped off to avoid over-application, which generally appears as a white, chalky surface. When dip or spray coating, diluting by a factor of 2 to 4 with additional solvent may avoid excessive build-up.
These products require moisture in the air to cure, and are generally cured at room temperature and in a range of 20 to 90 percent relative humidity for 1 to 2 hours. Low humidity and/or low temperature conditions require longer cure times. Mild heat acceleration of the cure rate may be possible but temperatures above 60°C (140°F) are not recommended. During application, the carrier solvent typically evaporates off quickly (except in the case of Dow Corning 1593 Cleaner/Primer, where the solvent does not evaporate at all), allowing the active ingredients to begin to react with atmospheric moisture and bonding surfaces. For optimal bonding, different cure times may be required for different temperature and humidity conditions. Users should determine the best cure schedule and conditions for their applications. The desired silicone elastomer should be applied after the primer, prime coat or adhesion promoter has fully cured.
Comparable Materials for Dow A-4040 Prime Coat
Spec Engine® Results