SO, back to the build...
The next step is to make the balsa strips that will serve as the fairings on the sides of the Atlas booster. Cut two strips off one of the balsa sheets in the kit 4 inches long by 9/16 inch wide. Cut two more 2-5/16 inchs long by 9/16 inch wide. Coat one side of one of the long ones and one of the short ones with wood glue, in a thin, even layer, and then press the two long ones and two short ones together. Wiggle them around a bit to ensure the glue is evenly spread, and then clamp them lightly with clothespins or small clamps, and set them aside to dry.
When dry, remove the clamps and sand the edges of the strips lightly to ensure they're all level and smooth...
Next, per the instructions, mark the strip 1/2 inch from one end, and the center of the strip at the very end. Then, using a sharp hobby knife and straightedge, trim the corners off to make the strips into an even point.
Now, using 220 grit sandpaper, invert the strip so that the line you drew across the end of the strip 1/2 inch from the end is resting line-side down on the sandpaper, and tilt it up to about a 10 degree angle and gently sand away the top layers of balsa until the strip comes to a shallow point on the triangular end. The angle you sand at should be flat enough that the point of the triangle lies flat on the sandpaper all the way back to the line across between the edges of the triangle... Correct the angle if needed and sand a bit until it's all even and smooth. Now, using the sandpaper carefully, round over the sides of the strip on the top side edges, along the entire length of the strip. The top corners should be rounded off, and the bottom corners left square. Basically you want to round them over to make a sorta flattened inverted "U" shape. Carefully extend this rounding over along the crisp sanded-in edges along the triangular tapered part down to the point itself... sand carefully to keep it all smooth and even. The finished product should look something like these...
Now, grab your 220 grit sandpaper and wrap it around the BT-60 body tube. Wrap the paper tightly so it conforms to the curvature of the tube very closely (don't use a whole sheet-- just a piece about 3x4-5 inches is ideal). Now, CAREFULLY sand the balsa fairings you just made UP AND DOWN the length of the sandpaper to curve the bottom side so it conforms to the body tube... BE SURE YOU KEEP THEM ALIGNED VERTICALLY ALONG THE LENGTH OF THE TUBE AS YOU CAN! You want them to match the curve of the tube, but you also want them to lay straight on the tube when you're ready to glue them on... it's not TERRIBLY difficult but it requires you be aware of your sanding position and motions... and consciously making straight-line movements and keeping the tube and fairing parallel with each other... I find that sometimes the edges want to stay a bit higher, so wrapping the sandpaper around your fingertip and sanding the CENTER of the underside of the fairing often helps to remove a bit more material, allowing the outside edges to snuggle down tight against the tube-- just don't carve the Grand Canyon in there-- you just want to minimize the gap at the edges, not create a huge void in the center of the strip where it should be gluing tightly to the side of the body tube...
Now we're finished with the fairings...
Later! OL JR
__________________
The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round!
|