exterior gloss has dried overnight dull!

[Drex]

Yesterday was a fine day for painting. I managed to get most of the black gloss on the wood early in the day, then later (about 8 pm) turned the wood round and finished off some areas that I had missed because I was resting the wood there..

Now, I note that the gloss I applied around noon looked very good, but the later gloss has dried very dull, decidedly matt! The contrast in very noticeable..

I was wondering why this has occurred?

Something to do with the overnight temperature drop? Possible condensation?

The paint is sandtex, oil based I believe and supposedly good for 10 years..

 

[Bosswhite]

Exterior Oil based gloss paints should not be applied after late afternoon, as gloss takes several hours to cure.

damp in the air flattens the gloss

 

[emilybronte]

Put another coat on the dull sections in a morning, when it's dry and sunny.