I am using my HVLP system for the first time, and am trying to shoot a book shelf with Varathane oil based gloss polyurethane.
First few coats went on pretty good. The third, which I hoped would be final, was pretty good, but not perfect so I figured... wet sand and try once more. Well... since then I have had nothing but trouble. That was 3 coats / attempts ago.
I *think* my problem is that I have thinned it too much. I shoot onto a test board, and I see the finish go from real speckly / dusty looking, to bigger "splotches", and then too a fairly uniform "wet" look... but even if I stop applying the finish at that moment, the finish runs.
So... it seems like when I have applied enough finish to get it to "flow" together to make a nice smooth surface, it is too wet, and I get runs.
Any experienced shooters have any thoughts?
I thinned with Mineral Spirits. Should I be thinning with something else?
Any help or comments (or even words of encouragement :-) would be appreciated.