: I have always used thin coats and a sqeegee in the past for filler coats
: often toped off by a brush and runs will form up to several hours later.
: This is with very thin coats. Before I used the Cab-O-Sil method, I put on
: 3 thin filler coats, each time getting gross runs on the vertical
: surfaces. It seamed like a lot of extra sanding that wasn't really
: necessary. My theory is there is always a better way.....just need to find
: it.

What seems to cause the runs and sags for me is the uneven resin thickness I was getting with the squeegee. Unless you pretty much squeegee all the resin off, I just wasn't able to accurately control the thickness. When I switched to my brushing method, the drips went away and I was able to apply more resin. I usually do the fill coat in one pass now. For most of the boat there is no sign of the weave after the first painted fill coat. And the places where resin does sag off, it comes off evenly because it started out even.

I just use a cheap bristle brush. I've had trouble finding the ones that don't shed a lot of bristles so I now bind in them with a line of CA glue around the base of the bristles. I still lose a few bristles but not as many as without the glue. I either pick them off with tweezers or scrape them off after the resin has cured.