Curing Polyurethane on Wood

Q. I own a specialty woodworking company, and we supply products like mantels, railings and moldings to the residential and commercial building industries. Some of these products are shipped coated, so we have spray painting and curing equipment in our shop. We want to upgrade our finishes and are looking at polyurethane varnishes because of their greater durability. In particular, we’re looking for a polyurethane varnish that will cure in our warm-air oven. We also have the option of running infrared heaters when needed. Can you help us find such a coating? W.J.

A. Curing in warm-air ovens is called forced drying. This method is often used in finishing wood and other heat-sensitive products to increase production. Both single-package and two-package polyurethane finishes can be cured in your oven, but remember to allow sufficient flash-off time before putting parts in a force-drying oven to prevent solvent popping. I suggest you ask your present varnish supplier or go to your local coating company store for product recommendations.