I just finished hot coating my second board with this new can of additive F and have come to the conclusion that it is bad. Got the same bumpy finish as I did on last board, so on the flip side of hot coat I didn’t use the crap and it came out Ok. On the side that came out crappy, I knew I had problems with it so I mixed it in with the hardener first and heated the two together before mixing in the resin. Still didn’t help.
So, if I quite using additive F in my hotcoats, will I have problems with my gloss coat not bonding well? Seems I heard that it aids in bonding successive coats. Anyone out there not using additive F at all?
I had the same problem as you did. The problem went away for me when I heated up the Additive F before I mixed it into the premixed batch of Hardener and Epoxy. I also set the hardener and epoxy in individual buckets of hot water (the temperature for taking a hot shower) for about 5 minutes before I mixed them together.
There is some sort of waxey stuff in there…maybe it’s wax, that blends when you heat the Add. F. But the epoxy has to also be warm so it doesn’t go back to a solid again. And the board should not be cold. Warmth lets it flow.
I think it depends on temp and especially humidity; too cold or too humid and you’ll get problems.
I have had 2 boards that had some bonding issues with the hotcoat to the lam… it was in the middle of summer here, which meant somewhere around 90% humidity. what happended, was when I pulled the tape off my pinlines, I had a few spots where the hotcoat peeled, leaving behind bare weave. All I did was sand down the area and paint it with some resin. They have been good so far.
As for the crater problems… I have only had it twice, both over pinlines… the likely culprit being contamination from sanding the pinlines.