From: larry@peak.psl.nmsu.edu (Evil Engineer doin' it the Cowboy Way)
Subject: Re: Light Covering...
Date: Wed, 30 Dec 1992 17:47:03 GMT
The truth is, I cover ALL my full-bodied CL stunt ships with silkspan and dope. Both planked foam and open-bay built-up wings. Fuselage, rudder, stab, and wheel pants: all exposed surfaces. This serves two functions: it adds tremendous strength, plus it covers balsa grain. And it does so with absolute minimal weight. (I've experimented with fiberglass/CA over planked surfaces with pretty good luck too.)
Of course, the finish requires more coats of dope, sanding, dope with talc filler, more sanding, more filler, then silver, sanding, more silver, then color, trim, inklines, clear, more clear, sanding, more clear, more clear, curing (for weeks) and finally sanding/buffing! But the result should be magnificent perfection. Well worth it for any creation as special as a CL stunt ship..
And it really IS low-tech. It does involve labor and time. But it requires only simple, cheap materials. And not an extremely high skill level. Covering with silkspan is not terribly difficult, it just requires patience.
Very light jap tissue finishes, used by the FF crowd use the same basic techniques, without all the filling and sanding and colored paint. Just tissue and several coats of clear dope. (If you want color, use colored tissue!)
I've also used super monokote plus epoxy paint on my profile stunters. Although the epoxy paint is super durable, it is noticeably heavier and more difficult to spray than dope. And, although super monokote seems to be the overall best (not easiest to use) plastic film, its durability is poor. Where monokote starts to bag and and loosen and raise after a few weeks or months, a dope and tissue finish endures for years or even decades.
It's no problem to strengthen your structure with tissue/dope, but it's really hard and very time consuming to get it beautiful. And it's even harder to get it light. Really !! Have you ever tried it ? I prefer a strong but light wood construction that doesn't need the strengthening of the covering and use film for finish instead. The only reason for me to use tissue/dope is it's durability, so I prefer that covering on scale-like models or on trainers which I expect to last longer than just some seasons.
If "harder" = "more time and labor", then I agree with your point. But the technology involved is actually quite primitive. As for lightness, I still contend that you'll have great difficulty finding an equivalent finish nearly so light as dope. Lightness is inherent to dope, since the most of the paint ends up evaporating.
If you are truly interested in learning how to get a superb dope/tissue finish, you should give Windy Urtknowski a call. He has a pair of good videos out which provide exact details on every aspect of this finish. His phone number is (201) 440-0905. However, be warned that he may talk your ear off. :-)