Building on the Cheap, Construction

[Malcolm R Foster]

Malcolm here, in Te Kowhai, near Hamilton. Anyone else out there interested in constructing Radio Controlled Model Aeroplanes out of Polystrene foam, covered with PVAed on brown paper, finished with sprayon car primer, and then colour spray paint? I've been doing this for years, with excellent results, and I'd like to encourage others with this.

You may have started with conventional kits, costing several hundred dollars, but you want to fly different planes, and not fork out thousands of dollars. Well, a trip to the hardware supplier to buy 8ft by 4 ft sheets of polystyrene foam is the way to go. They are available in many thicknesses, and if you add wing spars of balsa, reinforcing with ply and/or carbon fibre tows, you can make very strong, light structures. Carving is more of an art than a skill, I reckon, and I tend to use a very sharp kitchen knife, and the full length of a snap-off type razor knife. I hone it on an oilstone briefly every few minutes, and it cuts fine. The secret is a really sharp blade, and keeping it moving. I don't use a hotwire to cut the foam. Then sanding to finish, before covering with brown paper from the Warehouse.

Anyway, this is just an intro article, I am happy to go into more detail or send photos if you are interested. Remember - planes as big as you want, for engines as big (or little ) as you've got, for as cheap as you want- example: 5 ft low-wing semi-scale "warbird" for OS 40, built for around $60. That includes balsa, polystyrene, glue, paint,wire and wheels. Not the engine and radio, of course.
The largest I have built this way so far is an 8ft span high wing plane, with an OS 65 LA up front.

[Yflihi]

Hey Malcolm

I've been doing the same for years as well. I use resene test pots for painting though, and good old polyurethane over the top. I actually find it ends up lighter than traditional built up if done right. Building a 1/4 scaler this winter, using a foam fus with balsa longerons.

Nick in the wintery south (Fairlie)