Frank,

I live in Central Florida.  As you may know, it rains every afternoon and is
very humid during the summer months.  It is cool and dry during the winter
months.

In Florida we first paint all wooden ware, inside and outside, with Copper R
Tox which is an oil based sealant.  After that dries for 24 hours we paint
only the outside of all wooden ware as follows:

1.  One coat of exterior oil base paint.  Let dry for 24 hours.
2.  Two coats of  exterior latex paint.

Many commercial beekeepers treat their wooden ware with Copper R Tox and then
dip the wooden ware in parafin.

I hope this information is of help.

Richard