I read in the last American Bee Journal (Feb. 2002) about the Woodworth Bee Company and how they soak their supers in paraffin instead of using paint. Check out the picture on page 105 and what he says about it on page 106.
Sounds interesting. They say you're supposed to leave the inside of a hive free of paint and such because of moisture. Well, every one of my supers gets a fair amount of wax coating from the bees anyway. Anybody have any thoughts on this?
Whatever you do, do it on both sides. This will equalize vapor transmission on both surfaces of the wood. For example, DON'T have paint on the outside and wax/propolis on the inside. If you have been in beekeeping long, you have probably seen the results of this practice, though you may not have realized the cause. The wooden boards will cup, when vapor transmission is unequal. Usually they will bend inward at the center. This means the tops of the end boards will bend outward enough to allow the frames to drop down past the recess.
If you paint or wax BOTH surfaces of the wood it will never warp, unless you use extremely low quality wood.
How long do you have to be beekeeping to have your supers warp?
I have been using some of mine for over 20 years, painted on the outside only and haven't experienced warping as you describe. My brood chambers have been in use outside for that time... although I have had to replace my bottom boards due to rot.
I am just stating my experience, not refuting yours.
Well, I did it. I bought an 18 gallon bucket at Home Depot and 50# of paraffin. I melted the wax on an outdoor cooker. This took several hours. I soaked each side of the supers at 240-260 degrees for about 7 minutes. They look beautiful. When you put a super in the hot wax, it effervesses as the air and water is driven out and replaced with wax. I thought there would be a thick film on them, but they came out clean and dry looking. I'll let you know in about 50 years if they hold up.