The fins were very lightly glued to the pads to mark them for primer coat removal. I only used enough glue to hold the fin on for a pencil line around the edges.
The fins were removed and the primer scraped off just inside the pencil lines.
I tend to sand off most of the gray primer so there should still be a good grab on the fillets outside the scraped areas.
The fins were glued on permanently and Titebond M&TG fillets applied.
The instruction set previously said to glue the fins on then break them off and reglue them, ostensibly for strength. Did they omit that step or am I getting ahead of you?
ReplyDeleteHi Phil,
ReplyDeleteTLP didn't omit this step. I found it pretty interesting. I'll explain more in the next post.
I am thinking that the fin/pad joints are not very strong given the size of the fins and the relatively tiny mating areas. Remember also that either part will be breaking with the grain of the wood as well.
ReplyDeleteOne approach is to cut the fin outlines out of the pads for through-the-pad mounting. But that would mean you have had to make the fins a little bit wider earlier in the build process.
The other is to poke some holes in the root edge of the fins and the de-primed areas of the pads with a pin to form glue rivets. That is what I think I will do when I build mine.
Hi Bill,
DeleteOn my model, I made the lower fins out of thicker basswood. I also made the pads flat, built up pieces, not the 1/16" thick balsa warped around the body tube contour. My gluing surfaces (root edges) ended up much wider than the kit instructions direct you to do.
I could have done through the wall but didn't think it would be needed. I'll find out after a flight!