First off..Did you follow the directions on the can?
Did you thin the lacquer with the proper thinner as indicated on the can?
Did you apply the finish too thick? This is very important with what your finish is.
Also important, but nothing to do with your finish problem....did you stop at the recommended finish sanding grit or did you go up one?
Listen to the manufacturer, not a forum.
From the ambient conditions you gave us, humidity was not the problem.
I have a lot of experience spraying finishing products, mainly lacquer but not the brushing kind. OK, so sprayed lacquer is normally applied in very thin coats of approximately 3-5 mils wet. We know you brushed, so you must be thicker than that. Now here is why this is important..................Envision a glass of water sitting on top of a picture, then place a clear piece of glass over it and look through it. Now place a slightly cloudy piece of glass over it and look through it. then place another slightly cloudy piece of glass over that Each layer of cloudy glass takes something away from the picture as you look through the layers.
So, maybe you applied too thick a layer of semi gloss ( the first piece of cloudy glass). Then you added another layer of semi-gloss and further clouded up your view and then again with a 3rd layer of semi-gloss.
The proper way to finish is to ALWAYS start and build your coats with a clear finish - always. (Unless you are using a sealer or primer as a first coat). Then you final coat can be a semi-gloss or satin or whatever you want. By doing it this way, you are maintaining the clarity of the finish through the coats and only knocking the shine or glare off of the surface. By adding more and more layers of semi-gloss you are in effect changing your finish to a satin finish, and if you do enough coats, you will end up with a dead flat finish, just like adding all the layers of of slightly cloudy glass.
If you add enough coats of semi-gloss, you will be losing the clarity and subsequently losing the ability to see the wood grain at its best.
Tony B Retired woodworker, among other things.
"Strive for excellence and settle for completion" Tony B
Last edited by Tony B; 06-06-2020 at 01:15 PM.