9.4.3 Upper Strake Half Installation

It was relatively easy to get the height of the bulkheads to within spec. However, the internal fuel tank baffles are another story. Because the bulkheads block the view of the baffles, you build them as close as you can based on the provided templates along with a lot of test fittings of the upper strake to make sure they arent too high! The installation process takes that into consideration. They have you mound up the Jeffco epoxy so that it squishes down when the top is put on. I wanted to get an idea of how much I’d need for each top piece, so I used some plumbers putty. I placed the putty on top at various locations, then put the strake top on to see how much each piece squished down. That gave me a good idea for how much Jeffco I’d need to place at each location.

IMG 2272

I'm using the putty to determine how much Jeffco epoxy I need to mound up on the tops of the bulkheads and baffles for sealing the tank.

You can see the results of my experiment below.

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Closeup shot of the now squished down putty.

Because the Jeffco cures so quickly, I did not have time to take photos of the mounded up epoxy at each location. Apprently the process worked, at least at the bulkhead locations since I could see squished out epoxy there. Yay!

The photo below shows the first strake top installed. Since we live in the mountains we have plenty of “free” weights available in the form of rocks to hold everything down. I used gaffers and duct tape on the leading edge to hold it into place during the cure.

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The first strake top installed! There's no lack of rock "weights" available here in the mountains so I'm using those rocks to weigh down the top while the epoxy cures. The tape is used to hold down the leading edge.

The wing and strake in the photo above lined up decently at the leading edge junction. However, due to a problem with the construction of the left wing (I was still learning, specifically that the instructions don’t always perfectly match what needs to be done now!) I knew that I’d have a mismatch here so it was finally time to fix that problem.

Luckily I saved all of the old foam core billets and in this case, that came in really handy since I used the billet for the right wing to fix the gap. The original billet is a huge, rectangular piece of foam. I did some pre-trimming on it before temporarily attaching it to the wing. 

Wings - Strake - Leading Edge Repair

Using some old foam to fix the gap between the inboard edge of the wing and the strake.

After sanding all of the Velocipoxy “finish” off of the area to be comvered by the foam, I epoxied the piece of foam to the wing using a new batch of Velocipoxy. After letting it cure overnight, I started to do the finish sanding.

Wings - Strake - Leading Edge Repair 1

Getting closer - a lot of carving and sanding to get to this point!

The leading edge needs to match the rest of the wing, and I need to get the curves and all as close to the original profile as possible. You can see the end result in the photo below. That piece of foam is actually quite thin up until the inboard edge of the wing where it thickens up to match the strake.

The duct tape on the strake is there to help release any fiberglass and epoxy that accidentally spills over. I’ll clean all of that up later when the wings come back off in preparation for the “big flip”.

Wings - Strake - Leading Edge Repair 2

The foam is now epoxied into place in preparation for the triax layup.

I precut a piece of Triax to the proper size and with all of the angles and such to get as close a fit as possible. You can see the end result below. I used standard EZ-Poxy to attach the fiberglass to the foam after first applying EZ-Poxy and Micro to the foam as a pre-coat. I still need to apply a finish coat of Velocipoxy over this, but at this point, the repair is complete!

Wings - Strake - Leading Edge Repair 3

The layup is complete - the gap is gone, and I now have a nice, smooth inboard leading edge once again!

There’s still strake reinforcement that needs to be completed. That’s coming up a bit later!

ui© John Trautschold 2018