Last time I talked about how big this airplane is. It is made up of a whole lot of very small parts, and I want to explain some of the small things you do with them that can make a big difference. If you are working with plans and patterns, or with old-time printwood kits, you get a sort of built-in pace setter…you must go slowly cutting and trimming each of those parts or nothing else will get done. With laser cut or die cut parts, it’s easy to let yourself jump in and start sticking things together. That’s not usually a good idea.
I have included a couple of pictures to illustrate several of the subtle little steps that can begin to make the difference between novice and master builders. The first shows what will become part of the stabilizer trailing edge (TE) brace. The entire part has been die cut well enough that it just about dropped out of the sheet, but on closer inspection it was clear that the little notches where rib tabs will eventually fit were not cut cleanly. It’s not hard to permit yourself to poke at the cutouts until the stubborn bits fall out…but…that’s a set-up for sloppy work. In this shot I’m using a single edge razor blade to trim the cutout neatly, eliminating any possible odd scraps of material that might compromise parts fit later on. Stuff like that does matter.
In the next two shots I am getting ready to laminate two stabilizer TE brace pieces into a single part. I’m using good old aliphatic resin wood glue…the kind that has to dry for a few hours…because it allows me a little extra working time to get everything fit right before the adhesive grabs. In the first image I have squeezed out a nice fat ribbon of glue onto one of the pieces. In the next you see the important part. I spread the glue evenly across the entire joining surface…no blobs of extra glue left to add weight, but also no dry areas where no adhesion will happen. It’s not enough to assume that fitting the parts together will squish the glue around to all the places where it needs to go. You know you have done it right when there is a barely visible line of glue squeezout around the entire assembly. Wipe away that away…the glue outside the joint adds nothing but weight…no extra strength.
The last shot shows the use of a long, straight sanding block to face off, or bevel, the fronts of the ribs where the leading edge will be attached. The instructions in this kit tell you to do this, but it’s easy to overlook. Sanding in that tiny little angle of precise fit matters…it’s the way to get the strongest glue joint with the least amount of glue, which means the least amount of weight. Remember, you are building an airplane, not a garden shed.
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