Builders' Forum Archives
Re: air bubbles in epoxy,
Posted by Laszlo on Nov 28, 2006
Tipping it with the chip brush is exactly the right thing to do when applying epoxy with a roller. The only thing different from what you did is to use a dry brush.
The irregularities are the reason you sand the epoxy between coats. When I was doing it, I applied very thin coats, to the point where it looked as if I wasn't doing anything other than getting the boat wet. That's just an optical illusion, it's actually working just right then. Then, every 3rd coat or so, I lightly sanded with #220 paper and a random orbital sander. The low spots showed up as shiny spots. I repeated this process until there were no more shiny spots. At this point I was ready to varnish.
It takes a while in calendar time to do this, what with applying all the layers and waiting for them to cure hard enough to sand every 3rd time, but the actual effort is not that bad. It requires more patience than skill. One thing that helped was to leave off filling the weave until the very last thing. My wife actually used the boat for a year unvarnished and unfilled. That helps with the impatience factor.
Yes you need the rims. The hatches won't seal without them. One way to simplify making them is to get the bonsai saw from CLC and cut them out with that. It's razor sharp, so the effort is minimal and it leaves a smooth edge. Since it's a draw saw and hand powered, you have an amazing amount of control compared to any power saw. If you notice a mistake starting to happen, you just stop pulling.
The easy way to make the rims is to draw them onto the wood and use the bonsai saw to cut them out just outside the lines. Take your time, don't be in a hurry. It doesn't have to be perfect as long as you don't go inside the lines. Then use a sanding block and #80 sand paper to trim down to the lines. Okoume is soft and will trim down quickly. You'll end up with rims that are even better than CLC's CNC machine can make.
So I guess the common theme is to make haste slowly, especially if you're building from plans.
In Response to: air bubbles in epoxy, etc by Jay on Nov 27, 2006