Deck is stitched and glueing has begun
Call me crazy, but I decided to try and use black epoxy for the deck seams. The materials involve black pigment and microfibres from Fiber-Tek. The pigment is added to the epoxy resin up to 10% by weight. Then the hardener is mixed in. Finally the microfibres are mixed into the epoxy.
I did some tests with black pigment and fillers. The basic options for fillers include wood flour, microfibres, and microballoons (in decending order of strength). I made a batch of epoxy and split it into three separate containers. I then added wood flour to one container, microfibers to another and approximately a 50/50 mix of wood flour + microballoons in the third container. I had ruled out using microballoons by themselves for this task. I figure that the deck could see some high forces pressing down on it, and if the deck flexes I don’t want the seams to crack. Microballoons apparently are significantly weaker than the other options. The microfibres ended up maintaining most of the black epoxy gloss, while the wood flour was quite a bit dulled (as expected). The wood flour/microballoon mix was similar to the microfibres in looks, but the microfibre mix was easier to work with.
I’ve put the first batch of epoxy in the seams, and so far the deck looks good. I’m a bit nervous about how much work will be required to get the seams finished. I’ll need to remove the stitches and then mask all of the seams again (which is really boring). Then I’ll add the second batch of epoxy to fill in the gaps and where the first batch sagged or shrunk. Then I will have to sand all of the excess epoxy off of the panels. I’ve already applied a coat of epoxy to the panels, so the black pigment should not have soaked into the wood. Hopefully it will come off without too much work.