Admittedly the humidity is quite high. I think it has been around the 55-65% range. I know this is much higher than the recommended humidity levels when finishing with nitro cellulose lacquer... but I don't have any options in terms of a controlled environment situation (or in terms of the humidity levels dropping).
However, in saying this; the humidity was roughly the same when doing my initial coats of colour and I had no issues.
Basically what happens is that after one coat of spraying I go to do the next coat and it's white and hazy immediately as it hits the guitar. Over the next couple minutes a lot of the haziness clears off but not all of it. This is why I thought it was more likely the equipment rather than the environment.
But I really don't know, you're probably right I guess.
Either way I appreciate the input. I'm just glad most of the spraying is done and I'm happy with how it's turning out after polishing.
(Just to be clear, yes I did sand off all the haziness each time that happened! hah).