Never is a long time as my Father would say

I use this stuff for fillets. Works well. Also for attaching the fins I used the 'double glue joint' method.

https://www.landmsupply.com/departm...=All%20Products

Like I said on the Baby Bertha the fins broke along the grain line. I think they were old and dry and brittle. Also I put the fins on wrong so the grain was running the wrong way

The Goblin the glue joint did not really fail, it ripped off the glassine and some cardboard with it.

On bigger models I do use epoxy and have learned to use JB Weld on the engine mounts. Had an old Big Bertha, thing probably had 2 dozen flights on it. One day I hit the ignition switch and the engine mount shot out of the centering rings, up the tube, popped off the nose cone and went flying in circles