Chapter 14 - Section 7

Shoulder Harness Blocks & Outside Lay-Ups



Preparing the Harness Blocks

I cut up the 4 pieces of (spruce) wood for the harness blocks per plan. Then I carved out the foam and glassed them at designated locations. Note that I rounded off the top corners of the harness blocks to fit the curvature of the foam. The foam corners are rounded off a bit to accommodate the 4 layers of UNI afterwards (Lay-up #6).


[Break] At this time I am out of my MGS285 resin, so are Aircraft Spruce and Wicks. The scheduled delivery is 2 weeks out at best. So, I shall be moving forward to Chapter 16 for the moment...






Outside Lay-Up #6

After about a week of waiting, my MGS285 arrived. The next day, I got the spar prepped and ready to do the outside lay-up. Since this lay-up requires the UNI to wrap around the top and all the way around the sides, I have to raise the entire center spar off the work bench on CS1. I propped up the center spar on a couple of 4x4 wood blocks atop my work table. Not realizing that the center spar is not well balanced (due to the thick spar cap on one edge - Section 6), it tipped over, fell from the work table and hit the floor before I could go oh-*!@#$%^&*. The drop put a big gouge on the edge of the spar end. Susann (my cool headed better half) handed me some dry micro. I packed in the dry micro and re-contoured the surface - all in 5 minutes (while I was chewing on my own stupidity & carelessness). After the exciting opener, the rest of the lay-up was long, tedious and tiring. We completed the entire task 12 hours later - but it looked good!


Trimming the Overhang Glass

Once the glass cured, I flipped the center spar over on the work bench. I used a fine felt tip pen and drew a line for the cut line along the seam. If you look close, you can probably see it. Using a FEIN tool, I trimmed off the excess glass and sanded smooth the edges. The entire task took me about an hour and...








it turned the center section spar to a presentable assembly. Notice the gouge at the end of the spar that was patched up with micro and glassed over.









After trim, I layed the wing root template against the trailing edge of the spar. The spar is about ~.05" narrower than the wing root on each side - which is desirable. The rounded corner of the spar made the gap look a bit wider in the picture.