Yesterday I skim coated the entire canopy skirt with epoxy. The idea is to fill as many pin holes and deviations as possible before moving to the priming step. The first thing I did today at the airport was to sand the skim coat to make sure everything was even and smooth as best I could.

Then I brought the canopy skirt home to allow me to prime with out folks at the airport complaining. Here is the canopy skirt ready for its first coat of primer.

And here it is after the first coat of primer. I have to say I’m really happy with how it turned out, and a bit surprised. Areas that I thought would look horrible are actually pretty darn good, and other areas that I thought were good still require some significant attention.

This left side of the cross brace is one of the worst parts – in the areas that will be very visible. There are some pinholes, a few imperfect applications of the carbon fiber, and in general it still looks a bit gnarly. However, its not far off.

Its hard to tell how good or not things are even from these photos. The light and shadow combined with the varying thicknesses of primer (I went pretty light with the first coat) can be deceiving, however the intersection of the lower stiffener and the rear bulkhead are fantastic.

The outside of the canopy is nearly flawless – granted this needed the least work out of the box, but I’ve paid special attention to making this smooth as it will eventually have a shiny clear coat application like the rest of the aircraft. The interior of the canopy skirt will have a some what more matte to reduce glare.

Again the lower stiffener to canopy skirt fillet is flawless.

The corner here has a little flaw – I’m pretty confident I can get rid of these.

After the primer had time to dry, I went back and sanded with 120 grit sandpaper. This area, as one of the high visibility areas that was worse than other areas got lots of attention.

A few pinholes – but again – very happy with how this looks at this stage. This is, after all, my first significant foray into fiberglass work beyond the empennage tips – which are child’s play next to this!

I didn’t prime the top one inch of the skirt – this area will still need to be bonded to the canopy, so there isn’t much point to putting primer there – quite the opposite in fact. I’d think primer would only serve to weaken the canopy bond.

I will not be able to get this 100% primed and ready for painting prior to the canopy installation. The canopy itself will need to be bonded and faired. Then I will make final adjustments to fit and finish. My goal at this stage is to use the filler primer to identify flaws and fix the flaws. There is no avoiding more priming and paint once the canopy is on, but I can minimize the amount of sanding and adjustment post canopy bonding.

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.

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.

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.

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.

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.