Problem Solver
Troubleshoot WEST SYSTEM epoxy
| Question | Answer |
|---|---|
| My clear coating has turned cloudy | Moisture from condensation or very humid conditions reacts with components in uncured hardener Solution Apply moderate heat to partially cured coating to remove moisture and complete cure. Caution – avoid out-gassing. See Safety. Use 207 Hardener for clear coating applications and for bonding thin veneers where epoxy may bleed through to the surface. Solution Apply coating at warmer temperature – epoxy is thinner at warmer temperatures. Apply epoxy in thin even coats. Apply moderate heat to release trapped air and complete cure. Caution – avoid out-gassing. See Safety. |
| Bubbles have formed in the coating over a porous material (bare wood or foam) | Air trapped in the material escapes through coating (out-gassing) as the temperature of the material rises Solution Coat the wood as its temperature is dropping – after warming the wood with heaters or during the latter part of the day. Apply a thinner coat, allowing air to escape more easily. Tip off the coating with a roller cover brush to break bubbles. Avoid out-gassing. See Safety. |
| A waxy film has appeared on the surface of my cured epoxy | Amine blush forms as a result of the curing process Solution Blush formation is typical. Remove with water. See surface preparation. |
| Pinholes have appeared in epoxy coating over abraded fibreglass or epoxy | Surface tension causes epoxy film to pull away from pinhole before it gels Solution After applying epoxy with 800 Roller Cover, force epoxy into pinholes with a stiff plastic or metal spreader at a low angle. Re-coat and tip off after all pinholes are filled. |
| My coating is running or sagging | Epoxy applied is too thick Solution Use 790 or 800 Roller Covers and roll into a thinner film. Warm epoxy to reduce viscosity. See Cold temperature bonding. Coating curing too slowly Solution Apply at a warmer temperature. Warm resin/hardener before mixing. Switch to a faster hardener. See Controlling cure time. |
| My hardener has turned red after several years of storage | Moisture in contact with hardener and metal container Solution Red colour is normal and will not affect strength. Avoid for clear or exposed finishes. |
| My fairing compound is sagging or hard to sand | Fairing material not thick enough Solution Add more filler until “peanut butter” consistency. Let wet-out coat gel before applying to vertical surfaces. See Fairing. |
| I’m seeing fish-eyeing in my coating | Contamination Solution Use clean tools. Prepare surface properly. Avoid wax, fingerprints, fumes, fabric softeners. Rinse after sanding – water should sheet, not bead. If beading, clean and repeat. See Final surface preparation. |
| My paint, varnish or gelcoat will not cure over epoxy | Epoxy not fully cured Solution Allow full cure. Apply heat if needed. See Cure time. Paint incompatible Solution Use compatible paint. Test first. 207 Hardener works with most finishes. Poor surface prep Solution Remove blush and sand thoroughly. See Final surface preparation. |
| My epoxy mixture has not cured | Off-ratio Solution Remove epoxy; do not coat over it. Check pump strokes and ratios. See Dispensing. Low temperature Solution Allow more time. Apply heat. Use faster hardener. See cure-time links. Insufficient mixing Solution Remove epoxy; mix thoroughly before adding fillers. Incorrect products Solution Remove epoxy. Ensure correct resin/hardener. Do not mix brands. |
| The epoxy became very hot and cured too quickly | Batch too large Solution Mix smaller batches. Spread out immediately. See cure-time + mixing links. Temperature too warm Solution Use 206 Slow or 209 Extra Slow. Applied too thick Solution Apply deep fills in multiple thin layers. |
| My joint has failed to bond | Insufficient cure Solution See above. Resin-starved joint Solution Wet-out surfaces first; re-wet porous areas. See Two-step bonding. Contaminated surface Solution Clean and sand properly. See surface-prep link. Bonding area too small Solution Add fillets, fasteners or scarf joints. Excess clamping pressure Solution Use only enough pressure to squeeze out a small amount. See Clamping. |