Strip Planking

I recently scratch-built a 1957 “Green Box” Nobler from the kit plan. I’ve tried to make it “state of the art 1968.” It does have the pin-type hinges, but no adjustable leadouts or tip weight. It’s as we built ‘em then.

If you’ve never built one of these, the kit provided a die-cut piece of 3/32” balsa you were supposed to wet, then bend around the bottom fuselage formers, adhering with regular model plane cement like Ambroid or Testors. Comes out very light, but over time, the wood would shrink, giving a “starved horse” look to the bottom of the fuselage. An alternative was to substitute a light block about 7/8” inch-thick, carve to shape, then hollow inside. No matter how light the block, the result is always heavier than a piece of 3/32” sheet would be. It’s also expensive, especially in 2024!

I picked a third alternative, strip planking. In this method, you use multiple strips of wood, slightly thicker than desired finished piece. I used 1/8 inch contest balsa, cut into ¼ inch wide strips with a Master Airscrew Balsa Stripper.

To apply the strips, first cut them all a little longer than needed length. Next, slightly bevel edges of the first two strips, then glue in place on alternative sides, using sigment as the adhesive. Plenty of pins helps too. Next, add two more beveled strips to alternative sides. Glue each strip to the next one and to the formers.

Soon you will need to begin tapering the strips at rear of fuse. Bit by bit, the strips will be trimmed shorter and shorter to close up the opening. Once done, it will look pretty ugly!

Let the glue dry thoroughly, then block sand with 80 grit paper to blend all into a pleasing shape and to smoothly mate with fuse sides. This will reduce thickness down to the desired 3/32”. There will still be some minor gaps likely in a few places. To finish the job, spray with a light spray of water, then “slather” on a liberal coating of balsa putty such as Model Lite (I get it from Brodak’s). Let dry, then sand smooth with 220 paper, dry, then lightly with 400. Finish the plane as usual.

There are several advantages to this method:

1. The grain does not all run in the same exact direction. This fact makes the result a “stressed shell.” It prevents sagging and getting the “starved horse” look.

2. It’s cheap.

3. It’s light.

4. It’s pretty fast—faster than carving and hollowing a block.

5. It’s adaptable to nearly any usual fuselage shape.

6. It’s way, way faster than molding parts and stronger too. Molded Balsa will always have grain all in the same direction with same tendency to “starve the horse”.

Molding makes no sense from a time and labor perspective unless you plan to build the same plan over and over.

Regular model glue, such as Sigment, must be used, as it sands at about the same rate as Balsa. CA’s and airplane glues are too hard to sand. Sigment is light too, as most of it evaporates.