Some amine hardeners react at the surface with water vapor and carbon dioxide, especially in cool, humid conditions, forming carbamate salts. The result feels greasy or waxy and looks cloudy, and it ruins adhesion for the next coat or bonded layer. It washes off with water and a scrub pad. Low-blush hardeners and warm, dry conditions avoid it.
Cold night in the boat shed, the laminate's got blush on it, wash it before anybody bonds the bulkhead.
Also heard as
- amine blush
- blushing
Related terms
Epoxy
A thermoset adhesive cured by reacting epoxy resin with a hardener, the benchmark for strong, rigid structural bonds.
Cure
The chemical reaction or physical change that turns a liquid adhesive into a solid that carries load.
Scuff
To roughen a bonding surface lightly with an abrasive pad or paper to remove gloss and contamination.
Adhesive failure
A break at the interface between adhesive and part, leaving one surface clean or nearly clean.