Friday, November 22, 2013

Topgloss BR

Rubbed down the test sheets and sanded with 400 wet sand paper. I found that the rubbing down was unnecessary because wet sanding with 400 did the trick rather easily. It became really smooth. I thinned the paint with 10% thinner (Jotun number 7), but that did not help one bit, in fact I could see some spots where the thinner dissolved the first coat and the vinyl primer.

The only solution I can see is to apply one more coat (no thinner this time), and then sand with 400 and or 800 and polish the surface. I will apply that coat tomorrow, and try some other brushes as well, a foam brush maybe, and then sand it and leave it for 2 weeks to cure properly, and then polish. If that doesn't work I will dismiss Topgloss BR altogether, also for my boat.

I also tested the paint with acetone and the thinner, Jotun thinner number 7 which is 75% Xylene  and 25% Ethylbezene, and alcohol. All three dissolved the paint very easy. I hope this is because it is not cured yet. The paint is fully dry in 6 h, but is supposed to take at least 5 days to cure at 23 C. The thinner also dissolves the vinyl primer easily, while acetone requires some work. The "Quick" spray enamel paint withstands the thinner, but is affected by acetone a bit better than the vinyl primer. What a mess. In any case it shows that latex paint is not such a bad thing, very strong and flexible. The thing with latex paint though, is it can withstand almost anything except Xylene.

Also received the faulty ribs and spar from Sonex today, so I can start on the vertical tail, once I finish the ailerons.

I had hopes for this Topgloss BR, high tech Polysiloxane that is supposed to be specially made for brush and roller. So far it seems pretty much unusable. I painted my fiber glass canoe some ten years ago with a 2k paint using a brush only, and the finish is 10 times better than this Topgloss BR.

  

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