I think I have been unconsciously ignoring this problem, but I am running out of time. My garage ventilation is terrible. The only thing that opens is the overhead door. Worse, it is in the basement of my house. I have to move air out of the garage consistently to keep paint fumes from backing up into the house. Last night I primed the inside of my rudder case just as a test because it will not be very visible. I did it with the door open wide. Fumes from that small piece were semi-tolerable, although with a large fan(s) in the door I may have been able to draw enough air from the garage to keep fumes out of the house. There is a door at the top of the stairs, and I can seal it if needed. I suppose I could also rig a fan in that space drawing from inside the house.
The next problem will be dust and bugs. Within an hour, two gnats had met their end on the wet primer. Not a big deal in this small case, but if that continues to be a trend it is unacceptable. I’ll need to either create a booth of sorts, or rent a space for painting.
The closer I get to the end, the further (and more expensive) it seems to get…
still plenty of sanding to do while I figure out how to make the painting work. Suggestions, advice, and sympathy are all welcome.
I tried to sand my test piece 24hrs after priming, and it is still tacky. It seemed to have cured at first, but after gumming up the sandpaper I found I could scratch off the primer completely with a finger nail.
It’s been in the mid to upper 70s F inside. My garage space gets air from the central AC, but relies on the poorly sealing garage door for exhaust. It does remain quite humid down there this time of year; there is a perimeter drain and a sump well that always has water in it. I probably need to move more air through the space. A failed test anyway.
Hi Aaron,
i sympathize with you 
first on the ventilation and paint fumes. as a starter, i work in the basement of my house through the epoxy phase and then when sanding and painting, i move to the garage.
my perspective is that you need to keep the garage door open and keep the house tightly sealed…the fan to blow the air out of the garage should, as you note help to keep it manageable…but you will, inevitably get a bit of vapor in the house if you are working like this. thats just the nature of it and i have not had an issue keeping it manageable as long as i keep the garage door open while the paint volatile compounds evaporate off.
in terms of dust and gnats, i try to work at times when the dust is down (not during pollen season) and i vacume my garage to keep it clean. you can also wet things down to keep dust down.
a couple of gnats are not going to be a problem. let the paint set and the gnats wil come off and you really are not going to notice it. don’t try to pick the gnats out of wet paint, it only makes it worse. on the paint, further, make sure you mixed it well and keep your coats thin so it drys to the touch quickly…that will give the gnats less time. i also turn all the lights off in the garage after painting to not attract bugs.
on the primer… primer and moisture in the air don’t mix well…candidly, i stopped using primer after trying it becuase i just had too many problems working with it relative to the improvement in appearance. primer almost has to be completely sanded off…its just there to fill pin holes and ittle divots. anything more and you are overdoing it and it will then make for very soft paint. its better in my view to just take the extra time to sand a smooth enough surface and paint that surface.
the primer is basically talcum powder…it is going to be very soft…that is why i said above that the proper use of this primer involves sanding almost all of it off. so i am not surprised that you said you could scratch it off with a finger nail. the other thing with primer is it easy to put it on too thick. consider also if it was properly mixed before it was applied, that’s an important step in the primer.
keep your chin up…sounds like you are making good progress. if i had to sum it up from my experience for paint: mix the paint well. very thin coats…even if it means you need more coats. primer, not worth the trouble relative to just doing a good sanding job on the epoxy itself.
Thanks Howard. On reflection I definitely put it on too thick, although I did stir for a couple minutes first. Another 18hrs and it still seems a little soft to me, but can be sanded now. I’m probably just not familiar with this product yet. I will sand it off completely and try a very, very thin coat. I’ve already purchased all of the primer I thought I needed, but maybe I won’t use it everywhere, especially below the waterline. My boat will not live in the water though; if I keep it at the club it will be on a lift under a cover when not in use.
I think I have a ventilation plan now that isn’t perfect, but will get me by. This whole project has been a learning process.