I’m wondering if I have a problem here.

I just installed about 600 sq. ft. of aspen tongue and groove ceiling. I wanted to get a coat of sealer on it before the drywall is installed. Before any finish went up, the ceiling was sanded evenly with 120 grit in a palm sander. Then, using full strength oil-based polyurethane to minimize drips, I had my helper apply the poly with a 1/2 inch knap roller. I followed directly behind him with a 4 inch china bristle brush and brushed more finish into the V-grooves between boards and tipped everything off. We went through about 1 2/3 gallons of finish which is consistent with coverage specs on the can.

The can also specifies that a minimum temperature of 50 degrees F must be maintained during application and drying. I have a min/max digital thermometer set up in the house so I monitored the temperature carefully. We applied the finish at 60 degrees and before heading home for the night, I turned on a small electic heater. This morning, I returned to the house to check on the temperature. It was 55 degrees, which was also the minimum overnight. Then I noticed that the knots in the wood had a cloudy white film over them. The rest of the wood looks fantastic. Obviously, the knots don’t absorb the finish the same as the rest of the wood. I checked with the paint store and was told that the finish just needs more drying time, but I thought I’d try for a second opinion here.

I’ve never had this experience before with any finish, so I’m a bit concerned. Anyone out there know what is going on and what I might need to do for a fix. BTW, I was planning on applying another coat when the rest of the trim is finished.