I've having a tough time getting that final "mirror" finish on my deck. I'm using "Flagship" varnish and I've had one of two issues. On the first coat, per instructions, I thinned it just a bit with T-10 thinner (recommended by the Flagship maker) and applied with a good brush (badger bristle?). I got quite a lot of what appears to be ultra-fine dust. (This is even with cleaning deck surface thoroughly, using a well cleaned, quality brush, using new, non-contaminated container for the varnish, using an air cleaner for an hour before varnishing, ad nauseaum...)

For coats # 2 & 3, I used unthinned varnish and the brush, etc. Results were a bit better, but I must have applied the varnish a bit heavy/thick because while the grit was largely gone, there were noticeable ridges (at least to me) in the finish. I presume this was due to the fact that the varnish is a bit thick and needs a bit of thinning to flow properly.

I'll sand it down...ONE MORE TIME :-) ...but would REALLY like to make the next coat the last coat for this year!

Has anyone else had issues trying to thin Flagship varnish with T-10? Perhaps T-10 is contaminated somehow and needs to be strained before using it? (I've only used a tablespoon or so at a time anyway...) I'm afraid to stir the thinner in too vigorously for fear of creating bubbles which will of course show in the finish as well. Is there an alternate thinner to try? Maybe running the air cleaner a bit longer prior to varnishing? What am I missing here?