Tonight, I screwed up my courage and made a diagonal cut along a 4 foot by 8 foot sheet of aluminum. This is the first piece of fuselage skin for my Bede BD-4C airplane.
I had been fretting about this cut for a couple of weeks. Being new to the whole airplane building “thing,” I am on the plane-and-a-half program. That means: I make enough mistakes that I remake enough parts that I am probably building about an airplane and a half in order to get one airplane’s worth of airworthy parts. I figure that remaking parts is part of the learning process. It doesn’t bother me any more; I expect it. But… my checkbook provided a lot of motivation to get the fuselage skin right on the first try.
The rear fuselage skins of the BD-4C are made out of 2024 T3 Alclad aluminum sheet .016 inch thick. This stuff is nice and light. The whole piece in the picture above only weighs about three pounds. It is, however, a tad bit pricey. First, .016 aluminum sheet comes by the linear foot at $11.95 per foot and the skin is 8 feet long so the material alone costs $95.60. Then add the fee for the box plus the crating charge plus the shipping and it would run me almost $200 to remake this part if I messed it up.
Fortunately, I got it right (so far). 🙂
What you see above is a rough cut of the skin. I cut this out with my pneumatic shears. Then I clecoed the skin to the top of the fuselage and drew around the fuselage shape with a marker (on the underside of the skin, where you cannot see it). Tomorrow, when it is light outside, I will take the skin off the plane, lay it out on the driveway, and carefully cut it to just the right size, using the lines that I drew as guides.