: Working two boats at once. I had a fairly thick epoxy base (5 coats, counting
: seal and wet-out) on the hulls (no fill coats on the decks, yet), of which
: I ROS'd one hull smooth. In doing so, I turned a lot of epoxy into dust.

Removing that extra resin was good. Stop now while you are ahead.

: I tend to lean towards the side of over-built, and thinking I'd like to
: replace some of that rock-hard epoxy that I just removed, only aiming for
: a smoother finished surface this time.

If you have gotten the surface smooth, STOP. Adding more resin has not been shown to increase strength. If you want it stronger, add glass.

Think of the resin as a glue which holds the glass in place. Conveniently, it is viscous enough to fill in the weave pattern of the glass--if you use enough--but that added plastic isn't adding any significant strength. If you have some resin left over, use it for another project, or save it for future repairs.

: I'm looking at varnish as nothing
: more than a UV protector for the epoxy.

That's about it. Oh, and it restores the glossy look you just sanded away.

Unless you have areas which are showing glass, it is time to get on with construction. Join the deck and hull, and that area smooth and go paddling. After a month or so of paddling a matte-finished boat, resand to remove any dings, and them put on your varnish.

If you want to overbuild, wait for a month of battle scars to show up on the hull, then (before you varnish) cover those areas with another layer of glass. Here you can indulge in adding more resin, since you seem to enjoy that process Once you've got an extra layer of glass over the areas you seem to ding up. Then you can varnish. Two coats of most varnishes will give you all the UV protection you'll need for a few years, but many people add more coats.

: . . .I'll try both the
: squeegee and tipping off the roller to see if I can get something a bit
: more controlled. . .

Why not try this on some other project instead of using your nearly-completed boat as a crash-test dummy. You are in a very good spot right now. Until you have a good technique for adding resin without getting runs, I'm worried that you'll just make more work for yourself. If you have done 5 coats, and each one had runs, The learning curve on this usually goes from many runs to a few runs to almost no runs to (finally, after some experience) just one run or two. I'd say the odds are against you getting a run-free coat in the next two tries. That means two days of coating, and two days of sanding--and it won't make things any prettier, or stronger.

: . . .And if anyone has more ideas, I'm all ears. I'd even pop
: for a quart of fast hardener if I thought it might be better to deal with.

The thinner you apply resin the less mass there is to build up heat--and heat is what accelerates the curing. So a slow hardener is bad news with thin coats of resin unless you are working in a very warm environment. So heat up your workplace, or buy that faster hardener.

If you want to try an experiment (please, don't do this on the boat!)
try heating up your resin before you mix it with preheated hardner. Soaking the bottles of each in a bath of very hot tap water for an hour or so can get them up to well over 100 degrees. They'll cool to aomewhere over 90 as you mix them and pour them into the roller tray, but even so, they'll go on hotter and should setup faster.The hotter resin mix will also be thinner, so you just might apply a thinner coat of resin when working with it hot, as well. The problem is that the higher temp may cause the resin to "kick" before you get it applied. So watch for that.

: The slow hardener is sssssslllllloooooowwwwwwwww.

hehehe. Yeah, but when you are working in summer, in Miami's noonday sun, with the temperture hovering well over 90, you really need something formulated to give you a bit of working time.

Good luck with this, or just forget it and go on to the next step.

PGJ