When most epoxies are exposed to the atmosphere (especially cold and damp conditions) a secondary chemical reaction can occur at the surface of the epoxy, leaving a waxy looking by-product called amine blush. This water-soluble film appears only at the end of the cure cycle, and never at all when WEST SYSTEM® 207 Special Clear Hardener is used.
Much ado is sometimes made regarding blush, but the reality is, it’s easily avoided and easy to remove. Continue reading
By Tom Pawlak —GBI Technical Advisor & Tim Atkinson — Senior Chemist
I recently built a double-ended paddle for my kayak. The blades were made of thin mahogany plywood coated with epoxy. I had coated all the paddle parts with two coats of epoxy the day before, and overnight a thin oil-like film had formed on the surface of the epoxy. This is amine blush. To ensure a good bond between the blade and the shaft, I removed the blush with water, dulled the surface with an abrasive pad, and dried the surface with paper towels. I’m confident using my new kayak paddle because the mating surfaces of the shaft and blade were properly prepared prior to bonding. Continue reading