My only recollection about using hairspray on a model plane goes way back to the days of silk and dope. From what I have read and gathered, after silk had been laid on to an airplane but not painted, folks would spray the open areas to seal the silk and keep dope from seeping through the weave. Puddling of the dope on the inside of the silk would add increased weight but not do anything to improve the finish. This was supposed to keep the finish as light as possible by limiting the amount of dope required to get good coverage.

That's my story, and I'm sticking to it.....

Bob