yes I am having that problem again this year. I have had to do 2 coats a few times to rectify the screw ups. I tried something today where i mixed it up and let it sit for 5 minutes, mixed again as the film started and lets sit another 5 minutes. The little hardened pieces that are the result of the film can be mixed back in to the mixture, as was told to me by the company a couple years ago, and i kept doing that until they stopped and then applied the epoxy in as thin a coat as i could get. Probably 15 minutes after i first started. PIA but it seems like it worked better and I still feel the finish is better than any others, wear wise, I have tried so I trudge on.
With all the mixing you will get tiny tiny bubbles in your mix but most will dissipate and you can always use some flame. Heck on a few plugs I am even using a regular can of Urethane brushed on in 3 coats and I kind of like that , with a lot less stress, and will see how it holds up this summer.
BTW nice plugs