Q.
I often wonder how other shops are handling their door construction/finishing schedules. The question is: to finish door panels before assembly or after?
In my shop, I pre-finish the panels (to one step below final topcoat) for peace of mind, but lately I have toyed with the idea of outsourcing doors. My concern, of course, is that the panel shrinks sometime down the road, exposing unfinished wood.
I'm in the Northeast, and winters can get mighty dry indoors. How are other shops handling this? Anybody with a good track record of post-finishing?
We had similar concerns about panels' raw edges showing up in the cold months, when relative humidity inside pushed the lower limits (we built for the Northeast as well). For the most part, we had good success using doors constructed prior to finishing.
Our supplier used tooling that cut a radius on the bottom of the leading edge of the beaded panel slot. That allowed a good hand with the spray gun to aim stain/finish a bit back and under the bead. This technique did accommodate a little shrinkage.
Of course it’s important that the door is constructed of well-dried lumber and that you accommodate possible expansion with properly sized panels (we typically allowed at least 3/16 of an inch per side). It’s also important, in the summer months when humidity is high, to finish the doors immediately after construction (or store in a low-humidity environment) to eliminate panel expansion prior to finish application.
The most difficult situation to accommodate seemed to be shaded and glazed finishes. These specialty finishes leave a bit of darker finish material at the panel edge for an antique appearance. Any shrinkage in this finish style can be very noticeable. In these situations I strongly recommend a flat MDF or veneer-core panel.
Michael Poster, technical advisor
After applying the stain we take a blow gun and blow the stain into the cracks between the panel and stiles/rails. We have never had problem yet.
