CMR 1/72 Sikorsky S-39
By John Summerford
Introduction
The Sikorsky S-39 is a smaller, single engine, version of the twin engined S-38 amphibian and seats five. Nature film makers Martin and Osa Johnson used both aircraft with their film safaris in Borneo and Africa during the 30's.The kit from Czech Master Resin is all resin parts, nicely cast—though a couple of small parts were broken, and includes a lovely rendering of the plane taking off of muddy water, two sheets of photos and narrative of the Johnson's exploits, and sheet of color markings and exploded diagram. Decals are for the giraffe spotted "Spirit of Africa" circa 1933/34 and a blue Varney Air Ferries ship based in San Francisco. An additional note suggests that the builder use brass Strutz. (You've been warned.)
Construction
Construction started with the hull by adding a reinforcing piano wire through the cockpit and out to the wheels. I'm not sure the resin wheel struts can bear the weight of the model, particularly after adding a nose weight. I glued all of the seats, bulkheads, and control sticks and painted the interior. I didn't bother with the instrument panel as it won't be seen. (As it turns out, if you model the upper hatches closed, as I did, the only things visible are the pilot and co-pilot seats.) Gluing the windows was a bit tricky as they have to carefully cut away from the baking material. Their fit is OK given that they are vac-u-formed. After sanding down the bulkheads, I glued the upper hull to the lower hull. A coat of primer, paint, and Future floor polish to the hull and outrigger floats they were ready for the giraffe spots decals. You should plan on spending an afternoon with the decals, as there are over twenty to apply. While waiting for each finishing step of the hull, worked commenced on the flying surfaces. The wing, engine mount, tail boom, stab, and elevator are molded as one piece with webbing to be removed from the booms. My example had a warped wing and I didn't notice it until I removed the webbing, I carefully heated the wing in hot water and straightened it out, but in the process managed to warp the tail booms. I suggest reinforcing the booms with piano wire on the bottom surfaces before cleaning the webbing. Control horns are molded into the elevator but mine were broken off, so I added new ones with bits of piano wire. The cross brace was added to the booms and then the bracing wires were added using monofilament thread. I made a jig to hold the model and glued new plastic struts to the underside of the wing that attach to the hull. I made another jig for the struts to make sure I had the angle correct and they fit perfectly. I glued reinforcing wire to the back side of the engine/radiator mount. I relied on these three points to provide most of the strength when the hull and wings were attached. (Once all of the struts were installed, the model became sturdy.) The fin/rudder and their braces were glued on. A coat of black primer and Alclad II was sprayed on, then masked and the yellow wing bar was sprayed on. A disaster happened when the masking for the yellow was removed. The Alclad and primer went with the masking, so I cleaned the area and spent several days repainting. When that was complete, the N numbers were applied. Another coat of Future was applied to the hull and then offered up to the wings. Once secured, I added plastic struts from the rear of the hull to the cross brace of the tail booms. The rest of the struts I used came from the kit and required some clean up and trimming. The last items installed were the main wheels, engine and propeller and there she sits, a model of unique aircraft.Conclusion
This is not a complicated kit, but neither is it fast building and requires a steady hand. If you want to make a show stopper, you need to supply your own struts. I recommend it for experienced modelers.