We have happy build days and we have not so happy build days.
I took the fin out from under the books. Looked okay.
I decided I wanted to round off the non-root edges. So I marked guide linesand sanded the edges with an emery boardand… look.It’s the same corner where the paper lifted up before, though I don’t think there’s a direct cause and effect there. Maybe that corner can be repaired. And maybe the stains on the paper won’t show, and the miscellaneous dings on the surfaces will get taken care of by the primer. Or maybe this fin gets the hammer.
My guess as to what’s happening is that the CA-soaked paper being much harder than the balsa requires a lot more force to sand, but then you catch the balsa corner and tear it apart.
An obvious solution is to not round the edges. I’ve referred to Chris Michielssen’s blog post here, where he says “Only the leading edge of the fins was rounded” and that was done before papering — the paper was rolled over that edge. I don’t have that option, so either I have to sand the paper and endanger the balsa, or I have to not round any of the edges… or if there’s a third possibility, I haven’t thought of it.
I’m thinking I’ll probably throw out this fin and make all three with square edges. But not tonight. I’m taking the rest of the night off from this. Tomorrow too, probably; busy night.