Yup, more fine-tuning. Tonight I decided to lay out and drill all the attach holes. Straightforward work; I located the end holes, figured out rough hole spacing, and use the rivet fan to drill the remainder if the pilot holes to #40. Then I got the bottom in place on the rudder and match-drilled using the pilot holes through the attach strip (plus one hole on each side through the rudder horn brace, to secure the forward corner of the glass piece),.

With the holes done, the alignment between the edges of the fairing and the rudder skin were set; I ended up doing a bit of fine-tuning on these, going through several iterations of removing the fairing, sanding the edge down a bit, and re-checking. In the end I had a pretty even gap all around, unless you look really close. At a distance, nobody’s ever going to notice anything:

With the bottom now clecoed in place, it was time to revisit the cutout around the control horn. I used a piece of 1/8” bar stock to lay a new clearance line around the horn, then got to sanding again:

Finally, after all that work, I think I’ve got this thing shaped up like I want it. I think it finally really is time to get that bulkhead piece epoxied in place to close out the forward end…next time. This was enough for one night.

So I thought that my next work session would be glassing in the forward part of the bottom, and maybe laying out the attach holes, but it turned out that I needed to do some more fitting work. I’d marked the edges of the joint strip on the rudder and put the bottom in place, intending to mark the holes, but I could see there were a couple issues to take care of. First, the “sides” of the bottom weren’t parallel/straight – they sort of flare out a bit, preventing them from sitting flush against the rudder joint strip. Second, the edge of the bottom also wasn’t straight, resulting in a wavy gap between the fiberglass and aluminum.

To fix the first problem, I took advantage of the ability to massage these gelcoat pieces a bit. There’s a wooden wedge piece I cut to fit inside the bottom, with angle pieces clamped to the edges. All those cleco clamps provide a nice setup for lacing the thing together with paracord; once the cord is pulled tight, this bows the edges inward. After getting this all set up, I gave the whole area some attention with the heat gun to help things move around a bit.

Next up was working on straightening up those edges. This isn’t particularly challenging, just requiring some work with a long flat sanding block, but it was more tedious than you might think. Getting the edges straight could be done on the work table, using the table as a “straight” reference, but once I got the edges acceptably straight and put the bottom in place…well, removing that material meant there was now interference up at the control horn. So I had to do some work in that area as well to get clearance back.

In the end, I still don’t have all the fitting done – I’m fairly happy with the mating edges, but I still need to fine-tune the clearance around the control horn, and then rework the adjacent cutout area back to a flat profile, which will be needed to match up with the bulkhead I’ll be adding later on. Maybe then I can get to the stuff I originally thought I’d be working on today…

Short session tonight – I just mixed up a batch of micro to fill out the forward ends of the elevator tips. I did this with the tips clecoed in place, so I could also work micro into the gap between the tip and the skin, since that needed filling in a few places. I’d hoped to maybe do some filling on the horizontal stab tips, but by the time I finished working the micro into the seams it was starting to stiffen up pretty well, so I think I’d be better just doing those tips separately.

One thing I did differently from the rudder tip – I didn’t temporarily pop rivet the tips in place. Getting the cheap rivets out was more annoying than I liked, so I decided to dispense with that step. It was a little more tedious to work around the cloches, but overall not bad at all.

Of course, as is the case with micro, currently thing looks pretty nasty, but with sanding they should shape up pretty nicely. We’ll see how that goes tomorrow.

The day after doing a layup is always fun – it’s time to rip off the peel ply and see if you did something right, or if it’s gonna be do-over city again. In my case, there was the additional mild concern that I’d epoxied the tips to the elevator in spite of taping up, but once again both tips popped right off with no drama. After removing the peel ply and putting them back in place, the front-end profile matches up far better than last time:

Next up was cleaning things up. The ragged edge where I cut the wet cloth got sanded to a nice straight line, and then I went to work sanding along the joint to remove the excess cloth and make a nice smooth scarf joint. With that done, the tips look a lot better already:

The next step is to slop on some micro and work on the final contour for these guys. Most of this will involve shaping the front end I glassed over, but I also want to fill the gap between the fiberglass tip and the aluminum skin. The photo above in particular shows one of the unsightly gaps that I want to take care of. Before doing this, though, I wanted to tighten up the glass-aluminum interface; right now the edge of the elevator skins want to curl up a bit. That just required a bit of work with a hand seamer, and eventually things were looking much more flush, and thus conducive to adding micro.

I also temporarily added the stab tips to get an idea how things will line up. Interestingly, whereas on the vertical the rudder tip needed to be built up to match the stab, here I have the opposite problem; I’ll need to build up the stab tips a bit to match the elevator. I’ve also got a bit of refinement to do between the tip and skin contour there, so overall there’s gonna be a decent amount of micro applied, which in turn means a good bit of sanding.

Initially I’d thought I might get to doing micro tonight but I ended up just doing prep work instead. I sanded all the tip pieces down to remove the gloss from the gel coat and promote adhesion when I add micro. I also sanded the epoxy skim coat on the rudder bottom that I added previously, so that piece should be ready for primer once I get the tail light fitted. Though as I type this I’m remembering my intent to add some more glass to the open part of the front end, so never mind that last part…

Not a lot to report tonight. I finished taping up the elevators after running out for more packing tape, got the tips clecoed in place, and laid up two layers of glass over each counterweight. I decided to trim the glass plies immediately rather than waiting for them to cure partially, since the goal was to make sure they were pulled in tight against the counterweights. I figured they’d be more likely to sit proud if I waited.

I think this was a good idea, but making it happen was somewhat annoying. At first I tried using a razor to cut the glass, but even something that sharp was more likely to drag the cloth than cut it. I ended up using my little pizza-cutter type thing that I use for cutting raw glass cloth, which did the trick but then was a lot of fun to clean up.

From the looks of things I’ll have much better results than last time; tomorrow we’ll get to find out if my optimism is merited. In the meantime, here’s another photo of wet glass and peel ply:

OK, back at it again. Hopefully we’re at the point where it’s not gonna get too cold for fiberglass any more this year. One thing I see from looking back is that I never wrote up a short build session from about a week ago, when I added micro to the closeouts on the h-stab tips that I’d previously closed in.

Tonight, though, it was time for the real fun – that is, adding glass to the forward edge of the elevator tips to enclose the counterweights. For this work, I’m basically just doing the work in place, using the counterweights themselves as my “mold.” So the first step is to cover everything in the area with clear packing tape to act as a mold release:

Then, it’s just a matter of adding plies of glass cloth. Before doing anything, I wanted to evaluate whether I could use single pieces of glass for each layer, or if I’d have to get creative with shapes to conform to the curvature here. The glass cloth I have is really good at conforming, but I decided to try test-fitting a piece of dry cloth beforehand just to get an idea. Not only did this show me that it would conform, but it also gave me a good idea of what I’d need to do with the wet cloth to get the conformation to happen – much better than figuring that out with wet plies.

For this task, I used the helpful tip of putting the cloth between two pieces of plastic, and working the epoxy around with a squeegee to get everything saturated. This is especially helpful with this cloth, since it’ll deform really easily. This way, the cloth retains its shape while being wetted out, and I can cut out each piece, plastic and all, and only peel the plastic off when I’m ready to apply. This also makes it really easy to cut out nice regular size/shape plies.

There’s not really a lot more to say, but here’s that same elevator tip after adding three plies and then topping it all off with peel ply. Tomorrow’s the really big day, when I get to find out if I did a good enough job with my packing tape…hopefully these tips don’t end up bonded to the aluminum….

Well, I almost talked myself out of working on the horizontal tips tonight, since it’s dropping into the 40s later, but eventually I decided to do it, and just bring the heat lamp into play if necessary. First up, I actually needed to fine-tune my balsa inserts a bit more. One thing I noticed as I was finishing up last night was that the horizontal tip profile didn’t match the elevators very well – it was a bit fatter not too far from where it joined the stab.

One thing I’ve learned is that these gelcoat pieces can be coaxed into a more permanent shape change by stressing them and leaving them that way for a bit. This is, in fact, how I handled these same pieces not fitting the stab curve very well – I stuck little popsicle-stick spacers in to spread the pieces to fit, and found that after a few days they were staying in that shape.

So last night, before quitting, I put a clamp on each stab tip to squeeze the open end to better match the elevator, and left those overnight. Today when I removed the clamps the tips stayed where they were, and matched the elevator profile much better. But that did change the shape of the open end, so I had to tweak the balsa plugs a bit.

After that was done, I got to work bonding the plugs into place. One thing I learned after closing the vertical stab tip was that it would have been better to lay up the glass cloth reinforcement over the wet flox mixture, rather than doing two separate work sessions. Makes sense – having the still-runny flox mixture under the glass means it’ll make much better contact, rather than trying to shape it around dried flox.

The concern I had with this was that without the plugs bonded in place, I was worried they’d move around as I was working the glass plies into place and wetting them out. That was easily solved by using a spring clamp on the open end of each tip after placing the plugs with the flox around them. The clamp also provided a handy handle while working with the pieces:

The fun part about working inside these tips is trying to wet the glass out without making too big of a mess. It seemed unavoidable to have an excess of epoxy end up inside, even when I tried hard to use the excess for wetting out. If I’d let the tips cure in the position shown above, that wouldn’t have been too bad, just a bit of extra epoxy weight – but these needed to be clecoed to the elevator while curing, to ensure that the whole assembly cured up nice and square. The last thing I wanted was epoxy running out for the tips and gluing these unfinished tips to the stab, which is why I topped everything with the peel ply. This isn’t really required here but it’ll help keep the excess epoxy from going anywhere it’s not supposed to.

The last step for the tips was to clamp the open ends again just to make sure they held snug against the plugs while curing:

With that done, I moved on to permanently mounting the (finally) finished vertical stab and rudder tips. These needed to be clecoed in, the mount holes drilled up to #30, then everything dimpled or countersunk as appropriate. Once that was done, the tips went back on one last time, and I went to town with the blind rivets. In spite of a weird hangup partway through – the pop rivet tool I was using spontaneously disassembled itself – I still got it done. Good thing I have two pop rivet tools, I guess.

Anyway, it’s been a long road but now I have the vertical closed out. Well mostly..there’s still the rudder bottom cap to finish out and put in place. But that needs far less work than the tips, so hopefully it’ll go a lot quicker…