Peter Bowers was a well-known designer and builder of both full-size and model airplanes. As an aeronautical engineer working for Boeing in Seattle, he was well qualified for his hobby pursuits of homebuilt airplanes and competition-class free flight airplanes. He was also an aviation photographer and historian with many books and magazine articles to his credit. Bowers' most famous creation is undoubtedly the Bowers Fly Baby monoplane, which won the Experimental Aircraft Association (EAA) contest in 1962 for the best low-cost, folding-wing plane that can be towed or trailered from home to and from the airport - the goal being to avoid expensive hanger or tie-down fees. The Fly Baby was much in the fashion of a large model as it was constructed almost entirely of wood - spruce and plywood. Metal was used for fittings, guy wires, engine mount, hinges, etc., but even the landing gear structure was fabricated from laminated wood. Critics said lack of spring loading would cause the gear to fail, but hundreds of Fly Babys were built and flown without reported landing gear failures. As designed, the wooden undercarriage and Cub-type were able to a absorb landing forces. Being an open-frame aircraft, it was of course covered with the traditional silk and dope. Between the full-scale airplanes that Peter Bowers covered and finished and the model airplanes he built, he became a real authority on covering technique. Some of that expertise is shared in this 1941 Flying Aces magazine article.
Number One: Dope along the upper main spar to fill the silk so that the tightening coat will not stick the silk covering to the spar.
Number Two: Hold the material tightly at the center section as shown. Pull the silk outward to the extreme tip, "tacking " it as you go along.
Number Three: Remove the wrinkles from the silk by pulling across the chord, at the same time working outward from the center section to tip.
Number Four: The completely covered wing is doped chordwise. Clear dope is applied with an inch-wide brush from center section outward.
by Peter Bowers
A poor covering job on a model plane is as unnecessary as giving a permanent hair wave to a poodle dog. Here, an expert gives you the dope on best ways and means with which to smooth out and even end that troublesome model finishing problem.
How many times have you modelers built a beautiful ship only to ruin it by putting on a messy covering job? No doubt, this has happened to most of you at onetime or another during your model building career. The purpose of this article, therefore, is to pass on helpful suggestions and best method of covering your model planes so that in the future your efforts will attain a higher standard of workmanship. After all, many things in life are still judged by their surface. So let's get right down to the bottom of this important phase of aeromodeling and cover this subject thoroughly.
Gas jobs are usually faced with one of two materials - silk or bamboo paper. Small rubber powered models, and more recently class "A" gassies, are covered with tissue paper. The method of application in each case, however, is the same. The covering is held to the framework of the craft with dope as an adhesive.
Let's assume that the first ship we are to cover is a small gas job using paper. We will start with the wing, as it is the easiest part of the model with which to begin.
First, lay a sheet of paper, larger than a single wing section, on the workbench, and then the wing panel is placed on top of it. Then trim around the paper with a pair of scissors or a razor blade, leaving a margin about half an inch wide all around the panel. Next, apply a thick coat of dope to the leading edge of the panel with a brush, and then lay the leading edge along one edge of the paper pattern. Pick up the wing and smooth the paper along the leading edge with your fingers. When the dope has set enough so that the paper can hang without pulling loose, dope each rib about one half the chord of the wing back from the leading edge. The paper is then rolled back over the ribs, smoothing it again. When the paper adheres sufficiently, repeat the process for the rear half of the wing. Work out all the wrinkles while the dope is still wet. After the dope has dried thoroughly, the whole wing should be sprayed lightly with water which will shrink the paper and remove small wrinkles.
While the water is drying, proceed with the fuselage and tail of the ship. The tail surfaces are covered in the same manner as the wing. On a flat-surfaced stabilizer and rudder, it is best to give one side of it a thorough doping so that the panel can be pressed down upon the piece of paper, thereby eliminating the necessity of having to cover in stages because of the quick drying dope.
The fuselage requires a bit more care in covering than does the wing and tail, especially if it has a round or oval section. When the surface has changes of curvature, it will be necessary to cover it in many small sections, rather than one whole side at a time. Use sections as large as possible to simplify your work. Sometimes compound curves can be covered with paper quite successfully - if the tissue is moistened first.
Posted January 25, 2020