sensei

I don't ever consider dent proofing an airframe because it will dent regardless if you hit it hard enough unless you place enough glass, resin, and of course excess WEIGHT on your airplane as ARUP has already stated. With that said, placing down .75 oz. cloth with whatever binder you use to apply over your balsa surfaces, polyester resin, epoxy resin, or as I use these days Minwax single component oil based urethane will kill the swell back that is inevitable to come back through the primer and topcoat after a few warm days in the sun, you can count on it. I love the way painted airplanes look, but I also love the way lightweight airplanes fly so I do what I can to to achieve both looks and performance. Sometimes I will cover in cloth and topcoat everything, sometimes in Monokote and topcoat only the wheel pants, cowling, and canopy deck, and sometimes I just topcoat an entire composite airframe. In either case primer surfacer adds weight fast so I load it on and sand it until everything is filled and leveled, then I continue to sand until I can see through the prime everyplace. After that I spray a very light dust coat of prime, scuff and topcoat. In all these images all finish work was performed utilizing the methods I stated.

Bob