ORIGINAL: furloughed ual
making wing fillets for a Pica 190-D9.....what are some ideas on what to use that's easy and light....the lightweight white spackling paste will crack and fall out.......gimme' some alternatives....thanks.....
I always found epoxy/balloon fillet sanding to be APITA.
I opted to make fillets out of balsa. Not on that kit, mind you, but on others.
Use appropriate widths and lengths of triangle stock cut from the softest balsa you can get your hands on.
Take your time and use 50% ammonia/water to get the triangle stock to conform to the airfoil and fuse (compound curve, there), tape or clamp it in place 'til it dries, shape with sandpaper depending on the radius (dowel or fingertip), and glue the fillets in place.
Toughen the soft balsa with a sparse coat of thinned epoxy - let it soak in, and wipe off any runs with paper towels. Buff with 400 grit, and apply a second sparse coat of thinned epoxy. The second coat won't penetrate much at all, and again wipe off any runs.
A final light buffing with 400 (or finer) will leave a paint-ready surface.
Makes for pretty tough and light fillets IMHO. They won't 'crumble' the way filler-based fillets can, and sand a whole lot easier than epoxy/polyester and balloons. Takes a bit longer, but I think the end result looks 'store-bought'.