Save your ZAP CA caps. When you drill some holes in a wing for wing bolts, insert and glue the Zap CA cap into the hole with the open end facing outward. They're just the right size to accomodate the size of the bolt head. Sand it flush with the top of the wing. Then drill and tap as normal. Voila! Now you have a very durable (screwdriver "ding" proof) liner for the bolt hole. The part of the cap that you drill will also accept the same (1/4 -20) tap, so when you remove the wings, the bolts will have enough "bite" to remain with the wing.

I tried to tap holes for my wing bolts and it didn't work. I'm now using blind nuts now, though I have never used a ZAP product.

An easy answer is to drill a 1/8" hole for each bolt, then use #8 hex-head sheet metal screws. They cut their own threads, and you can use a nut driver to tighten them without slipping and gouging your wing.

I believe if you hit so hard you fracture two quarter inch nylon bolts you will generally tear out the fuselage blocks anyway, so you might as well use the metal screws and solve the problem! Been working well for me for a number of years.

Clair Sieverling