To start, the plastic sheet covering the bench had gotten quite a few nicks in it and was pretty dirty. The nicks in the plastic take on sharp edges that tend to snag the cloth. Up until now I had just slapped a piece of packing tape on any egregious burrs, but that was just a stopgap since the edges of the tape can still snag. So I stripped the old plastic off and applied a fresh new piece.
With that out of the way it was time to start cutting some cloth. Now from what I learned reading the Burt Rutan EZ stuff it is important to keep your cloth strands straight, at least if you are trying to maximize strength. The glass fibers work in tension and if you let your weave go all zig-zag the strands have to be pulled straight before they start working; so the straighter the strands the stiffer the panels.
If you haven’t ever worked with glass cloth, it’s not like cotton duck. The fibers are slick and they slide all over themselves. They’re easy to pull out, skew, spread, snag and run, and/or bunch up on each other. So when I roll out some to cut I like to square the weave up to the front and side of the bench, then cut across a single strand, give or take a strand. It takes a little more time to finesse the cloth into shape, but it supposedly (and logically) makes a difference.
Anyway, here I have rolled the cloth out and squared it up to the table. I stuck a couple of spring clamps on the back of the bench to act like wheel chocks and make sure the roll didn’t accidentally roll off.
After cutting a couple of pieces that way I realized that I was spending a lot of time getting the weave straight going back and forth lifting each end of the roll to take its own weight off and let different areas of the sheet slacken so that I could brush it out gently with the palm of my hand. If I tried to pull from the corners it would skew and sometimes run under my fingers (compacting strands together); so I decided to set the roll up on an “axle” so that I didn’t have to handle it so much.
I used a long narrow drop (that I had ripped off of the Red Grandis I used for the hatch ribs) as the axle. To keep the edge of the cloth even with the edge of the bench I rigged up this shaky cantilevered strut to reach out away from the bench on one side…
… and used that marking gauge I made the other day as a prop on the other end. After this pic I added another clamp over the top of the axle to keep it from moving around.
After tweaking things a bit to get the heights at both ends even and the roll parallel to the back of the bench, it took a lot less effort to square up the weave.
Due to the limited bench space, after cutting each of the side wall front section plies I rolled them onto a smaller cardboard tube for safe keeping. To keep things neater when it came time to unroll these cut pieces and use them, when I had the next piece cut I would unroll the smaller tube over the top and then roll the whole stack at once. It was a little tedious and it made sense to pay attention to the order of the cuts (to avoid having to shuffle their order and handle them more), but I seemed to start getting a rhythm. Well, I only got four pieces cut, but I can see things moving along better now that I have a setup to deal with the big roll easier. Rather than break that setup down and wrap the roll back up (to keep it clean and free of shop dust), I just used the packing paper it came in as a drop cloth and covered it up on the bench.
We’re moving on.