I need some help. I have been searching the archives, and applying what I read, but how on earth can I brush/spread on an epoxy coat (gloss, hotcoat or color work) without bubbles, some of which are as big as the layer is thick, making for pinhole/fisheye problems? I am using RR2000 and the fast hardener, and have tried various combinations of the following:
Additive F in 1cc and 2cc per oz hardener, as well as none at all
X-55 Accelerator in prescribed amount (1cc per ounce of mixed resin/hardener)
Denatured alcohol to thin the resin
Heating the resin before mixing
denatured alchohol wipe on board before coating
fans blowing across board while hardening
heating board outside before coating
foam vs bristle brushes vs plastic spreaders
slow vs fast brush speeds
soft vs harder brush pressure
I started with large separations, but using the above techniques, I can eliminate separations and I can sometimes reduce the amount of bubbles, but they are always present, and I cannot pin down the combination of things that will eliminate them. I glass in an air conditioned room (usually around 75 deg depending on how often the outside door is open), the humidity in my region is around 50%, and sometimes dusty, but I wipe down the board (with denatured alcohol) before taping off the rails and just before mixing the resin up.
I am new to board building, and shaping went very well, lamination was a breeze (I think, no bubbles under glass so far). I may have left the lams too dry, but I didn’t want the glass to float. I also may have moved the resin too much, as when I was removing the excess from the flats, it would sometimes come off on the squegee/spreader rather frothy. Hotcoats were the kicker for me, though.
Even on a cheater coat I tried after an hour after lam, I still got bubbles, and even if they were not felt at the surface after hardening, I could see them in the low spots of the weave between fibers. These very small bubbles were a constant regardless of whether or not a cheater coat was used on the lam to fill it in some. I usually just use the weight of the brush when brushing, unless I have to move resin to a dry area. Unfortunately, that is where the bubbles are worst, the dry areas that I brush the resin to after I pour it out. More brush passes just make the bubbles worse most of the time. I have tried ‘babysitting’ coats, but I just seem to make as many bubbles as I eliminate when I do this. The more I mess with it, the worse it gets, especially after the resin thickens some as it cures.
I cannot pin down the combination that will eliminate them, and there has to be a right way to do this. The archive has all sorts of praise for epoxy, as do I (it has been very easy to use so far), except for this problem. The only thing that bugs me is how some people boast that they can coat a board at an ounce of resin per foot, but then some of the fisheye posts say to coat thick (I imagine more than one ounce per foot) to avoid separations/bubbles. How can this be? Just different environmental conditions? Lots of advice, but also lots of money spent trying to follow the advice, guess it just goes with the territory when trying something new.
Other info: 2# Insulfoam EPS, sealed with Epoxy/Microballoons, 6 oz silane glass.
What do you guys think?
Thanks,
MM