The hive bodies that I use are pine. I have decided this year not to paint my
new hives but Instead  spray them with Tompson's Water Seal or the equivalent.
After I assembled them I used a paint brush to give them a coat or two. This
sealer is absorbed very fast and appears to leave no residue.
Then in the fall, when the bees are in the hive I plan to use a garden sprayer
to give them another coat. Quick and easy.
I have a 8x12 mini barn that has wood siding and I use this technique each
year and have found no rotting or the like for now 8 years.
I have painted the hives in the past and the paint peels ...etc. over time. I
like the natural look of the hive and I have not encountered any problems with
the bees thus far.
This season has been good and look forward to the next.
Dave Oakes