Just tried using some cab-o-sil to keep epoxy from getting runs in it on the final fill coat. I mixed the epoxy first, then added a about 1/12 by volume of the fused silica and several things happend:

1st, the epoxy mixture in the cup got a lot of air bubbles in it, which is what I allways try to avoid.

2nd, I could not get the cab-o-sil to completely dissapear into the epoxy. Lumps remained and trying to squish them out only introduced more air (kind of reminded me of mixing pancake batter, with the lumps)

3rd, the cab-o-sil did prevent all runs, which have been a big nucense in all previous fill coats, but it left hard little pimples which are from the lumps of cab-o-sil.

4th, the epoxy did go on a little cloudy. I did the hull and sides, so I am not overly concerned about the cloudiness right now.

My questions are: how do you get this stuff mixed so it completely dissolves with no lumps and how do you get it mixed without it instantly introducing air bubbles?

after it cured for 24 hours, I took a scraper over the hull to reomve all the hard little pimples that were left behind. (thanks to those on this board for the scraper suggestions) By the way, I loved useing the scraper. Since I'm building in my living room, this really saved from a major dust clean up. If any of you have not tried leveling the fill coat with a scraper, do yourself a favor and experiement with it.

Thanks in advance for the cab-0-sil advice.

Tom