Mill Glaze: Myth or Reality?

Abstract

Since the mid-1980s, a condition called “mill glaze” (also called planer’s glaze) has sometimes been blamed for the failure of a coating on smooth flat-grained siding and some other wood products. The exact cause of this problem has been a subject of controversy. Many people believe that the coating fails as a result of the planing and/or drying processes. They speculate that the milling or planing process overheats the wood and brings more water-soluble extractives to the surface, creating a hard varnishlike glaze. They attribute overheating to dull planer blades.

Citation

Knaebe, Mark. 2013. Mill Glaze: Myth or Reality?. USDA Forest Service, Forest Products Laboratory, FinishLine, 2013; 2 p.