Inside, not outside the boat, inside the hull, and leave the heater turned on while, and after, you're working!
But, you need a temperature controlled heater, or at a minimum, an overheat shut-off.
Don't use too much heat or it may catch fire and that would really spoil your day.
Reread my previous post above.
Even a plastic enclosure around the boat would heat up more for relatively low $$. You can use 1x2 wood strips and staple the plastic to them and then screw them to the ceiling. This is how you build a cheap painting tent as well. You are basically reducing the building size. The heater can go under the boat and plastic around the bottom, but not as good as a tent. Heat loss is highest up; so you can also double the plastic on the ceiling it it is super high or open above.
I have a friend in Alaska that uses a double plastic wall system for his boat area.
Sorry for the delay, guys, I've been busy. I tried placing a small heater inside the boat through the hatch (the only heater that fits). Unfortunately, after running for several hours, all it did was raise the boat temperature by 1.5 degrees, to a total of 35° F. That was several weeks before, when it was still relatively warm outside. I tried laying making an enclosure around the boat, but truth is, my workshop is so cramped that there is no practical way to work with such an enclosure. So instead I spent two days heavily insulating my workshop with polyurethane foam, cloth sheets on the gate, etc. I closed off every single gap into my workshop, making it pretty much watertight. I also added one more 2 kW heater (bringing total heater power to 10 kW), which is approaching the maximum limits of electrical safety fuses. Despite all these attempts, the temperature in my workshop is now below freezing point, and the temperature differential between outside and inside my workshop is just 2 degrees (outside 28°F, inside 30°F). There is nothing I can do but suspend the boat build until spring.
The plastic tent is a good way to improve the work area for better cure times in cold weather.Even a light bulb inside a plastic tent creates enough heat to make a difference.When you have concluded the filling and fairing will the paint be sprayed or brushed?
I plan to use roll-and-tip, as I don't have paint spray facilities.
On to the good news: I managed to get my hands on a small sample of peel ply. I made an experiment to see how well the peel ply works. I did it with a 5oz cloth on a small piece of plywood. I divided that piece of ply into different zones for testing:
1. Zone 1 - as dry as possible. Wet out fiberglass thoroughly, but then squeeze out as much epoxy from it as possible.
2. Zone 2 - normal wet lay. Enough epoxy left on top of fiberglass so that it shines.
3. Zone 3 - same as 1, but with microsphere-thickened epoxy on top.
4. Zone 4 - fiberglass overlap.
5. Zone 5 - same as 1, just without any peel ply (this is like a control group).
After taking off the peel ply:
Now this is very difficult to evaluate, so I sprayed some black paint to truly reveal the surface.
In this pic you can see fiberglass at the top that wasn't covered by peel ply. Below it, there are zones with dry coat, wet coat and microsphere coat. Essentially no difference. The fiberglass overlap goes right down the center. It is very noticeable where fiberglass was laid without peel ply, and with peel ply, it is much better - but still a somewhat visible bump.
Now, in lots of locations I got these little pinholes:
They look like there wasn't enough epoxy, but as a matter of fact, this is the zone where I put on A LOT of epoxy. So I don't know why these pinholes appear. Perhaps it might be plywood outgassing?
I poured some water over this piece to make the surface shine and reveal even more detail.
As you can see, this reveals some minor bumps, ridges and overall rough look of the texture. I am unsure of the reason behind these imperfections. I laid down that peel ply very carefully, and went over it many times to compress it down as hard as possible. Of course, this is a hundred times better than using fiberglass without any peel ply, but this is definitely NOT paint-ready surface. There are just too many imperfections, and the roughness of the surface would substantially increase the wetted surface area of the boat, creating lots of drag. This surface should definitely be primed with epoxy and sanded smooth prior to painting. Can't sand it right away - these pinholes are just too deep, and I would be digging into the fiberglass.
But even disregarding these pinholes, the surface is not even close to a glass-like, baby-butt-smooth finish that I'm aiming for. It is rough and has hills bumps here and there, even though I went over this peel ply with squeegee and roller like 20 times at least.
Is this how peel ply is supposed to work? Still requiring additional fairing and sanding afterwards? Because as I complained earlier, adding that thin, consistent layer of fairing compound is a chore and massive expenditure of epoxy... How do people achieve that glass-smooth surface with peel ply?
