Carlson Skunk Works

June 8th, 2016

AMF 14H MARANDA SN:1026 Making Sawdust June 8th, 2016

Posted by Roger in AMF 14H Maranda SN1026, news

Covering the wings has begun. The bottom of the left wing is covered and now I need to modify my workbench to make it “friendlier” to the fabric as I work on the wings. However, that is what I WILL be working on. What has been accomplished is getting the left wing ready for covering and getting the bottom covered.

The wings have been installed on the plane for a couple of years now. The old hanger was pretty drafty and dusty. Therefore, the top surfaces of the plane were/are really dirty and needed to be cleaned. All surface imperfections and glue joints needed to be fixed and smoothed. This is just like the control surfaces that I covered last winter. I found that a fine rasp worked really well for doing this.

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Then I applied anti-chafe tape to the ribs and to the edges of the plywood wherever I thought it might provide an abrasion issue.

Since I have a limited number of extra hands, I decided to cut the fabric at home where I have enough room to roll out the fabric on the basement floor and cut it by myself. I measured the length of the wing and allowed for some excess on each end, then cut a length of fabric 17 feet long. When I was ready to spread the fabric out on the wing there was a pretty stiff wind and I had to close the hanger door.

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I forgot to take pictures of the first pieces of fabric that I put on the wing. I started by putting fabric over the ends of the aileron cutout and the wing root. Then I glued the bottom fabric to the wing.

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The big decision for me was how to deal with getting the pitot static tubes through the fabric without problems. What I ended up doing was laying the fabric on the wing and tacking the leading edge in place, then I marked where the back side of the pitot static tubes came through and marked a straight line forward as a cutting guide. Then I took the fabric loose and cut a slit in the fabric just long enough to allow the pitot static tube to go through. The cut started at the mark for the back of the tubes and cut forward for about two inches. After the initial shrink of the fabric I made two doilies to reinforce this cut. One doily had a notch cut to fit the back side of the tubes and was installed first. The other doily had a notch cut to fit the front of the tubes and overlapped the first doily. The result seems to be pretty solid.

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The lift strut attach fittings needed to come through the fabric as well and I made doilies to fit them, too.

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The same went for the jury strut attachment fittings.

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Rib stitching will be done where the ribs are open. However, the wing root and the wing tip have plywood covering a rib each. I don’t know how to stitch these, so I decided to glue the fabric to the plywood at those areas. I thought about drilling holes in the plywood to accommodate the lacing needle, but I don’t really like that idea. I will continue to give this some thought.

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Figuring out the position of the fabric edge for the leading edge took a bit of thought. I watched the Stewart Systems videos and read their procedure manual several times. What I ended up doing was working backward. The leading edge finishing tape needs to be four inches wide. The top fabric needs to overlap the bottom fabric by three inches. The leading edge tape should cover the fabric joint in such a way that it sort of faces the air as it meets the wing. Anyway … I marked the place where the fabric edge should be glued at 11 1/2 inches forward from the back of the leading edge plywood bottom edge. That works fine for the main length of the wing. I just eyeballed the same type of position toward the wing root on the area where the wing tapers. It seems to have worked out ok.

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The bottom fabric was extended to the wing tip. I glued the wing tip fabric on the top of the Hoerner wing tip. I did have to cut out for the wing tip light mount. I am planning to put another doily over this area after the top fabric has been installed.

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We moved the wing to the wing racks to allow us to modify the workbench. Once the workbench has been modified I will put the fabric on the top of the wing.

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