West Greenland Kayak Build Time Lapse 8: Coating the kayak. Build time so far, about 40 hours.
I’ve recently started experimenting with mixing rare earth pigment directly into the two-part polyurethane. The advantage to this is that the finish is far more colorfast and UV resistant than using acid dye to color the fabric, especially in the darker colors. The disadvantage is that it’s much more difficult to apply evenly without making an ugly, streaky mess.
The problem is that even slight differences in coating thickness show up as color changes. My rolling technique creates a fairly even layer, but as always, rolling too much for too long is a big mistake. Also I like to follow each layer with a careful smoothing with the scraper card which is a lot less forgiving.
The material has to be cured enough that when you hit it with the card it will smooth down any imperfections, but not so cured that it won’t self level after that. Also every variation in pressure and speed shows up as a color change.
There was also just a lot of stress from pushing the envelope of pigment concentration. I chose to mix black and brown this time even though I’ve seen the polyurethane have boat-ruining chemistry problems with too much black dye and pigment. As usual I’m using myself as a guinea pig to find the disaster threshold so I can tell my students how to stay below it.
Overall I’m pretty happy with how things ended up but it’s far from perfect and I had to be ridiculously disciplined not to make it worse by over-rolling or over-scraping.
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