Yet more brackets, foam, carbon, and aluminum composites

I spent some time this weekend working on Goat. I split about 50/50 working on foam versus cutting more brackets.

I have quite a large pile growing and it's getting time for some more fun assembly! Several, if you notice, are multiples up to 4 of any individual part. For the cabanes in particular, I need one bracket each side and then a duplicate pair for the other cabane. Several of these parts also need to be match drilled to align with each other, so some of these are not yet drilled. Fortunately, only a pair of each need to be match drilled, so it's not like I have to drill through four and have them all agree!

Next I moved to the rudder to do some foam and carbon work. I typically dislike this more than the metal work which I like less than wood work. However, I took my time and vacuumed several times and it was much more enjoyable than normal.

First, let me say I am not pleased with my first rib installation job. I have determined I will pull this one off and replace it in the future. I thought it more important this go around to get a rib right before I destroyed my old one. One step forward before one step backward.

I already had the fiberglass collars wrapped around the leading and trailing edges from months ago when I did the original rib. These I sanded a bit to get rid of sharp edges (ouch, pointy!) and to create a better surface for bonding the second layer of glass. One rib was already cut, so I simply tack-glued that on with some quicker setting epoxy. This helped keep it from moving around on me. I used a straight-edge and a razor saw to put a slice down the middle of the rib. Then I took a scrap piece of carbon and ensured the hole was large enough for the rib carbon to fully seat in the foam. After trimming a new piece of carbon to length, I glued it in the slot and double checked to keep the top surface flush. Before I add the wrap, I will install the other two ribs.

I did a little metal work on the horizontal tail too. I finally had a piece of scrap 3/4" x 0.035" tubing long enough for the elevator. I squared it up and drilled holes for the bolt and rivets.

I think doing rivets is fun, so it was exciting to have six to do all at once! Maybe my next plane should include more rivets. Okay, I admit that pop rivets aren't the most structural, so maybe I would say differently if I had to use real rivets.

I also watched an EAA Homebuilders video on the proper technique for installing cotter pins in castle nuts. The elevator hinge line eventually gets this locking feature, so I thought it would be nice to brush up on (who am I kidding, learn) the proper techniques.

While I had the foam out and my scrap 3/4" tubing handy, I started the rudder pedals. They are quite simple, just two tubes and foam in the middle. They will receive a wrap of 6oz fiberglass cloth to seal the foam and give it more rigidity. Whereas they look rather unfinished now, once the fiberglass goes on, they should look and feel much more rigid.

You might be able to see that I roughed up the aluminum in order to bond the foam on. This simple step is really important for getting a good bond. Imagine that the sandpaper is making several miniature scratches in the surface that the glue can creep down into and get a grip. You can bond things to glass this way even! Don't try it though, it's a good way to ruin a window...