I am fabricating a set of quartersawn white oak exterior doors. They are approximately 24" W X 90" H X 2 1/4" thick. They are being built with stave core lumber. What size clearance do I allow at the center of the two doors? What degree angle do I use to back bevel with the doors being so thick?
(Architectural Woodworking Forum)
From contributor T:
AWI suggests 1/8" in 2" bevel on the door edge. I think that amounts to a 2.5 to 3 degree bevel.
As to the gap issue, if they are exterior doors, you are going to need some type of astragal - either "T" or flat - to help seal out the elements. The gap itself should be about 3/32. The oldtimers used to carry a silver dollar in their pockets to use as a gap gauge.
Do the math. EMC for your area (adjusted for exterior), MC of your stock, with the width of the stiles (crossgrain) times four and some ciphering will tell you how much they will swell. Use the handy-dandy shrinkulator on this site. With some practice, you can get pretty good at fitting them right the first time. After 35 years, we go out about 3-5 times a year for refits.