One advantage to working in the attic is I don't have to deal with the weather. I can't do smelly work up there but sewing envelopes doesn't need smelly chemicals.
The lower wings have cutouts for the ailerons so I had to sew the long seam aft of the front spar first. Once I got the wrapped piece properly positioned I marked a line for the forward of edge of the 36" lower panel. To mark the line I measured from the aft edge of the wrapped panel.
The seam was pinned and the fabric rolled up for sewing. The excess on the upper wrap was trimmed after the seam was sewn.
The seam was sewn as before. The straight edge of the fabric makes a nice line to follow while sewing. My 36" high work tables allowed me to sit with a tall stool while sewing, much easier than standing.
With the forward seam sewn the fabric was fit to the trailing edge and aileron cutout. I didn't sew the short edge of the cutout. I only want one layer of fabric in the aileron gap and that is easier done with glue.
After sewing, the envelope was put back on the wing and clamped in position at the root rib.
With the fabric in position the tip was pinned and sewn.
The envelope comes off very easily but it takes a little wiggling to get it back on.
The tip looks very loose but it shrinks very tight and smooth.
Once I cut the lower fabric to fit the root rib I ironed it smooth at 225 degrees to make gluing easier. I then folded it under the fabric and Ironed a crease so it would fit snugly at the corner while gluing about 2" along the top of the rib.
The upper fabric was shrunk and stretched to fit the root rib and trimmed to overlap the lower fabric about 2".
I did glue in the attic by opening the door and keeping it aired out. After the glue dried I closed the door and turned the heat back on. There isn't much gluing with an envelope. You can also baseball stitch these seams instead of gluing.
To prevent a build up of fabric in the aileron gap, the seam on the small end of the aileron cutout was made the same way we did it for that end of aileron. The upper fabric was wrapped around and glued to the lower side of the cutout box structure. The lower fabric was then glued to it and trimmed to the corner.
The long seam for the aileron cutout was placed in the center of the false spar. I wanted it out of the way of the hinges but not near the lower corner. Any build up of fabric along the lower corner limits the downward travel of the aileron.
A small cut was made to get the aileron push rod out of the wing before gluing the root, etc. You could install the rod after the fabric is finished, but it's hard to work through those inspection rings.
I did the first (250 degree) shrink of the outer rib bays before cutting the fabric to expose the pitot-static connections, then finished shrinking. I wanted the fabric snug so it wasn't likely to move much after cutting the hole.
It's always surprising how tight the fabric gets when you shrink it.
We've got some wet weather coming so I'll get the fabric on the lower right wing and then start rib stitching the other upper panel.
The long seam came out very straight after all the shrinking.
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