I used it to coat the entire frame of the depot wood , metal and all.
It takes a week to completely dry to the touch. I also coated the top bottom and all sides of the floor in the caboose.
Since this I have learned something! Polar seal, the roof coating, can be tinted with a compatible latex exterior paint and will make a rubberized paint that will fill small seams and voids and protect the wood. The c/d grade plywood floor of the depot was coated with two coats of polar seal and was in the weather for 7-8 weeks before it was dried in. It looks as good as the day after the first coat. It dries in about 30 minutes to a some what chalky finish.
Pardon the muddy foot prints.
I did notice that when I added the exterior latex the chalky finish was gone. The Grey on the depot is a mixture of 1/2 polar seal and 1/2 paint I also added a huge blob of drywall compound to try and arrive at a stucco like finish. It has been on the exterior of the depot 4 months now in rain snow and bitter cold and still looking good. See my tiny house , depot thread for more details.