Friend/customer has an expensive set of front doors, pair of 3-0x8-0 mahogany. They face mostly west with a short two-story porch overhang ... maybe 6 ft. They were varnished for most of their life, but a couple of years ago she had the outside painted black ... the insde is still varnished. The outside has been refinished about three times cuz the paint develops small bubbles and blisters. I did it the last time, using Sherwin Wms Duration.
I sanded the outside lightly, although inn some places the paint easily came off to bare wood, and applied 1-2-3 primer. This was done in June, I think, when it was very hot & dry. Now I notice that there are several small bubbles again. The house is always air conditioned or heated, so the humidity should be pretty stable. There is one crack in a panel joint, maybe 1/16" x 3", but the bubbles are in several places, even in the upper panel where there are no visible cracks.
Help. Any ideas why the bubble appear, and how to avoid them next time? Before you ask, the doors will always be black, so that's not an option.
Whenever you are asked if you can do a job, tell'em "Certainly, I can!" Then get busy and find out how to do it. T. Roosevelt
I'm sorry, I thought you wanted it done the right way.