Fastback 47


I’m trying hard to move the canopy build along quickly. I’ve been stuck on this stage for far too long due to multiple other life events and I need the excitement of a new stage! There are not too many remaining big ticket items. I need to weld the taxi latch, the roll bar, and the gas strut nut to the existing roll bar assembly. As the roll bar is a structurally important weld, and all of the welds will be highly visible I’m going to have an expert welder do it. That being the case, I want to try to get all three welds (roll bar, taxi latch plate, and gas strut nut) done at the same time. Before I can do this, I need to have the position of the taxi plate determined, and the height of the roll bar. I don’t want to weld the roll bar and then find out that it is too close to the top of the canopy. Thus, I need to get the canopy mated to the canopy skirt before I can do the welds.

Today’s first project was to determine the position of the taxi latch plate.

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I drilled the center stiffener to accept the large metal plate that holds the spring and set everything in its final location. Then I clamped the taxi plate in place and tested the alignment. Mike Bullock suggested we tack weld the taxi plate in place before final welding. It will be a bit of a chore to do so- we’ll need to bring a generator and the welding equipment to the hangar. I had hoped that playing around with alignment that there would be another way, but unfortunately I do not see one. The taxi plate only marginally overlaps the roll bar. There isn’t a great way to clamp or mark it in its final position for transport to another location for welding. Its just too precarious.

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After this I measured and marked the location for the other end of the gas strut – where a nut will need to be welded to the roll bar. Unfortunately, I didn’t take a photo.

This brings me back to final touches on the canopy skirt. I used some more rage gold to deal with some problem areas.

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After a couple more applications of rage gold and subsequent sanding, I applied a skim coat of epoxy. Some folks recommend thinning the epoxy. I have quickly learned two things – Dan Horton is the de facto community expert on fiberglass, and his work product is direct evidence of his expertise. I follow his advice whenever I can. (See the carbon fiber in the middle of the canopy skirt). He recommends against thinning epoxy and I found a few sites that talk about the negative effects of doing so. All in all, I think thinning epoxy for the purpose of a skim coat / pin hole filling isn’t a big deal. You aren’t really worried about the losses in strength or cure time. I experimented with a small amount of thinned epoxy, and I didn’t like it. Particularly in the summer temperatures, I find the viscosity of regular epoxy more than sufficient for my purposes. So that’s what I used. I used fast hardener on the outside where application was relatively easy, and slow hardener on the inside with the more complex intersections. I rushed a little bit and got some runs. My best advice – take your time on the skim coat. Like every application, it will save you time in sanding.

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Finally I did some fine tuning of the instrument panel cover. I added flox around the foam inserts in the corners and sanded multiple areas to fit. I debated whether or not I should do some final fitting of this to the canopy at this point or later, and settled on doing it after the canopy was mated.

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