This guide is designed to help identify and prevent potential problems associated with using WEST SYSTEM® Epoxy. If the solutions described here do not resolve the problem, contact the technical staff.
|Problem Table of Contents|
|The epoxy mixture has not cured after the recommended cure time has passed.|
|Clear coating turned cloudy.|
|Waxy film appears on surface of cured epoxy.|
|Hardener has turned red after several years storage.|
|Runs or sags in coating.|
|Fairing compound (epoxy/407 or 410 mixture) sags and is difficult to sand.|
|Epoxy became very hot and cured too quickly.|
|Bubbles formed in coating over porous material (bare wood or foam).|
|Pinholes appear in epoxy coating over abraded fiberglass or epoxy.|
|Fish-eyeing in coating.|
Off ratio: Too much or too little hardener will affect the cure time and thoroughness of the cure.
Low temperature: epoxy mixtures cure slower at low temperatures.
See Mixing in the User Manual.
Resin starved joint: epoxy has wicked into porous surfaces leaving a void at the joint.
Wet out bonding surfaces and apply thickened epoxy. Re-wet very porous surfaces and end grain. See Two-Step Bonding in the User Manual.
Contaminated bonding surface.
Clean and sand the surface following the procedure in the User Manual. Sand wood surfaces after planing or joining. See Surface Preparation in the User Manual.
Bonding area too small for the load on the joint.
Increase bonding area by adding fillets, bonded fasteners or scarf joints. See Bonding Principles in the User Manual.
Too much clamping pressure squeezed epoxy out of the joint.
Use just enough clamping pressure to squeeze a small amount of epoxy from the joint. See Clamping note in the User Manual.
Moisture from condensation or very humid conditions reacts with components in uncured hardener.
Entrapped air from aggressive roller application.
Amine blush forms as a result of the curing process.
Blush formation is typical. Remove with water. See Special Preparation--Cured Epoxy in the User Manual.
Moisture in contact with hardener and metal container.
Red color is a normal condition. It will not affect epoxy handling or cured strength. Avoid using for clear coating or exposed areas where color is not desired.
Epoxy applied too thick.
See Barrier Coating in the User Manual.
Coating curing too slowly.
See Controlling Cure Time in the User Manual.
Fairing material is not thick enough.
See Fairing in the User Manual.
Epoxy not completely cured.
Allow the final epoxy coat to cure thoroughly. Allow several days if necessary for slow hardeners at cooler temperatures. Apply moderate heat to complete the cure if necessary. See Controlling Cure Time in the User Manual.
Paint incompatible with epoxy.
Epoxy surface not thoroughly prepared.
Remove the amine blush and sand the surface thoroughly before applying paints or varnishes. See Final Surface Preparation in the User Manual.
Batch too large.
See Understanding Cure Time and Dispensing and Mixing in the User Manual.
Temperature too warm for the hardener.
Use 206 Slow or 209 Extra Slow Hardener in very warm weather.
Application too thick.
Apply thick areas of fill in several thin layers.
Air trapped in the material escapes through coating (out-gassing) as the material's temperature is rising.
See Out-Gassing caution in the User Manual.
Surface tension causes epoxy film to pull away from pinhole before it gels.
After applying epoxy with 800 Roller Cover, force epoxy into pinholes with a stiff plastic or metal spreader held at a low or nearly flat angle. Re-coat and tip off coating after all pinholes are filled.
Contamination of the coating or surface or improper abrasion for the coating.
Contact the Technical Staff if you have additional questions.