well, now that its said and done, i realize its mostly my fault, but i had a amateur painter screw up flattened black pretty bad. it was that hot rod flatz offered by a online paint shop. i had a so-called painter spray it on for me yesterday { in a booth/w a stata gun}and he sprayed it on way too dry. it looks like painted black 60 grit, here and there.what i realized after was he sprayed it on like a base coat. i even have zebra stripes on the hood! i guess my warning is that hot rod flatz is sure not a base, without clear, like i should have realized. it needs to be flooded on like enamel that it is.
I've used tons of this stuff and it worked for me. The only thing I don't like, is that it could be little flatter straight out of the can but I just added extra flattener, to make it work.
Sounds like the wrong speed of reducer. Reducer speed too fast/air temp too high= drying in mid air and a gritty surface.