Joshua's RV-9A Project

Finished the canopy skirts by stripping off the excess Sikaflex that oozed out of the joint and riveting the skirts in place.  All rivets were easily squeezed except five, which were bucked.  One of the nice things about Sikaflex versus something like Proseal is that, while it sticks with vigor to any properly primed surface, it doesn’t stick to things not coated with Sika primer; so it’s easy to not worry about the ooze-out, and once it has cured, just scrape or rub it off.  Cleaned all the dust off the canopy frame & underside.

Pulled out the prop and various related pieces — spinner, bulkheads, spacer, crush plate — and set to work making the blade cutouts in the spinner.  Measuring, making cardboard templates, and cutting, then shaping with a file, followed by lots of iterative fitting and filing, was the order of the day.  Got it to the point where it fits, though the cutouts will need to be cleaned up for a consistent gap width.

With the first batch of fiberglass parts done, today saw the attachment of all the empennage tips to their respective stabilizers and control surfaces.  The emp fairing was set aside for the day the tail is installed at the airport, and the spray booth collapsed until the next round.  The only remaining item for the emp is that the taillight screw holes on the rudder need to be tapped to remove some excess micro that got in them.  After that, the emp parts will make their way to the airport at some point, to wait with the wings for the Big Move of the fuselage.

While working on the left elevator, also final-installed the trim pushrod and cotter pins.

The plastic covering on the canopy was the original as shipped in the finish kit, and had become quite tattered, along with being covered in dust and overspray of all sorts — I removed it, and will cover the canopy with layers of saran wrap to keep it pretty in the interim.  Today, cleaned, prepped, and attached the canopy side skirt pieces to the canopy frame.  Currently, they’re clecoed in place to let the bead of Sika cure, then I’ll add the rivets.  Also fabricated the exterior canopy lift handle (pilot’s side only, thanks) and drilled to the frame.  The canopy is very static-y when cleaning with a microfiber cloth, which means it didn’t stay clean for long, but every dust particle in the shop was attracted to it.

Re-bled the right brakes again, but still have a soft right brake pedal compared to the left.  I see no leaks, even under pressure, where air might be entering, so I can only blame the bleeder tank somehow.  Sort of disheartening, as the original system fill was rock-solid on both sides…too easy.  But the leaks at the pedals had to be fixed.  I wonder if draining the whole right side and refilling would provide better results.  I also wonder about the design of the bleeder valve, and whether air can’t find a path to enter there.

Decided to look at the installation of the crotch straps.  Pulled the seat pans and found that it would work well to simply drill a new hole in the crotch strap bracket, up from the giant factory hole.  I marked them in situ, and drilled both to 1/4″.  The geometry of this area requires an angle drill, but my largest bit is 5/16, so I will need to procure a 1/4″ threaded bit to complete the installation.

While messing around in the fuse with seatbelts, I happened to notice that four bolts were never put in the center section — whoops!  These are the bolts that go through the inboard tubing support brackets, just outside the fuel selector, top & bottom on both sides.  Obviously, I installed those bolts.

Two sessions today.  In the afternoon, sanded the K36 smooth — that stuff sands very easy — and sprayed a topcoat of DPLF epoxy primer, per the advice of folks at VAF, who say it is more resistant to oil, etc.

In the evening, came back to respray one elevator tip, whose finish was marred when the plastic sheet that makes up the paint booth perimeter fell on it while drying.  Argh, and it doesn’t look quite as good as the other, but good enough to last until the plane is painted for real…just trying to make sure the glass is protected and looks decent here.

Also tightened one more leaking NPT elbow on the passenger’s left brake, and re-bled the left brake system.  Replaced the broken right brake bleeder screw, and re-bled that side, but there was a continual stream of tiny bubbles in the fluid and the right brake is definitely softer than the left.  I think pumping up the bleeder tank put bubbles in the fluid when the level in the tank got low, so I filled it back up and pumped it up.  I’ll leave it set overnight to allow the bubbles to settle out, and re-bleed again tomorrow; hopefully that’ll fix it.

Mixed up some Super-Fil and worked it into the remaining pinholes on all the fiberglass parts that were sprayed yesterday.  Next will be sand the filler & spray another coat.

Pulled the top skin off and moved a couple pins on the ADS-B connector, since newer versions of the box have a slightly different pinout.

With the top skin off, found that a few of the elbow fittings on the brake cylinders were leaking fluid.  Removed the hoses and turned them in one more rotation, which, at least initially, seems to have cleared up the slight leaks.  Re-bled the brake system with fluid, and in the process managed to snap the nipple off one of the bleeder screws.  Dangit — at least it was only the nipple, so the brake system is closed, and I just need to order another bleeder screw.

Reconnected the oil temp sensor wire, which had been removed in a previous session to install an oil line.

Hooked up the new serial converter and it works; checked communication with the Pmags, and verified the configuration in the APRS tracker.

Finally, a work session with something more than sanding.  Worked a bunch of list items over a full day in the shop:

Brushed epoxy on the front of the top rudder tip, filling the pinholes in the micro which was sanded yesterday.  Added a blob of micro to the trailing edge, where the glass tip ended short of the metal portion.  I’ll refit this to the rudder tomorrow and sand the tip TE to match the rudder.

Set up a plastic-sheet spray booth, cleaned the HVLP gun,  and sprayed PPG DPLF epoxy primer on the canopy fairing, HS and VS tips, elevator tips, rudder bottom, and empennage fairing.  After that, it was time to air out the shop and bring it up to temperature again, as the epoxy primer and subsequent gun cleaning step kick off a lot of fumes.  I found only two pinholes in the canopy fairing, both over screw heads.  The emp fairing has a goodly number still (as I expected), and the tips have a few.  I’ll let the primer cure overnight, then fill the holes and sand level before laying down the K36 which is the next step in finishing.  That puts the second coat on schedule for Monday or Tuesday, though it looks like I may have to work on Tue night.  The recoat window is one week.

On to the cowling, I cleaned up the cut line on the rear of the inlet duct, then fabricated a piece of airseal and a metal backing strip, fitting them around the bottom of the duct.  This will mate up with the top piece, which is installed on the airbox, to seal the gap between duct and airbox.  A test fit, after tweaking the alignment of the airbox, showed it worked well.

Next, I countersunk all the rivet holes for the cowling hinges, and drilled some “ooze holes” in the hinge to give epoxy something extra to bond to.  Sanded the cowling and the hinges with a rough grit, and laid a bead of epoxy/flox along the hinge lines.  Clecoed the hinges on, then riveted them down, and cleaned up the flox that squeezed out all around.  Ran hinge pins through the hinges to make sure none of the eyes were epoxied shut.  Also floxed/riveted the oil door hinge to the cowl and door.

Put rivets in the remaining 5 holes under the left side canopy deck, originally left open to attach clips to hold the static line.  One hole was behind the center section cover, and inaccessible for bucking, so I used a Cherry rivet instead.

Torqued the nuts on the control cables at the quadrant, and the stopnuts on the control horns attaching the cables to the quadrant levers.  Verified that cotter pins were installed on the horns (they were).

More sanding, and nothing but sanding.  Sanded down the coats of epoxy that were applied to the canopy fairing last night; I think it’s going to come out alright.  Masked off the canopy and Allison helped me move it to sawhorses to wait for spraying.

Sanded down the empennage fairing, so that can be primed too, though there are a couple spots that need a bit of micro and followup sanding.

Spent the rest of the session starting work on the emp tips: final-drilling the holes, dimpling/countersinking, and sanding for primer.  One of the elevator tips needs a little micro along the seam, and the rudder top fairing will, too.  Hoping to get the rest of the tip work (just the rudder bottom) done tomorrow and apply some micro, then spray all this stuff midweek.  I think it’ll be a mental boost to have all the glasswork except the cowling “done” (for now, and excepting gear fairings which will probably wait until after first flight.)

Began the day with some excitement; nearby -9A (and now -10) builder Mike Behnke was gracious enough to bring his plane down to Red Wing this morning so I could have my first RV flight — a great one!  The day was warm, calm, and relatively clear, and Mike’s plane looks and flies great.  My only experience being in 150/152/172 types, the stick-and-pushrod controls were a new thing, and a joy to fly; no slop in the control system, and just a bit of pressure required for control.  We did some turns, stalls, a bit of sightseeing, and Mike demonstrated an autopilot-coupled GPS approach.  Also got to see the AFS screens in flight, as his panel is practically identical to mine (both equipment and layout).  We also chatted about fiberglass, transition training, inspections, first flights, and so on.  Many thanks to Mike for the opportunity!  It’s another inspiration to work through the endgame of my project.

On my way out of the airport, I stopped by the hangar and pulled the fuel caps from the wings (and taped over the filler holes), as I’m considering sending them in to be engraved with the required markings, rather than using a sticker.

Into the shop after lunch, I spent several hours sanding the micro filler on the canopy fairing.  It turned out pretty well, and I think I’m going to try and move ahead with it.  To that end, I squeegeed on some straight epoxy to seal the micro and fill pinholes.  I’ll add another layer or two, then sand and see where it sits.

I used the excess epoxy to seal the inside of the emp fairing.  I’m hoping to get the rest of the emp tips ready to spray this week, then spray a whole batch of glass one night.  Once the tips are done, the emp parts will move to the hangar.

Drilled the dataplate to the fuselage — I’ll send this in for engraving with the fuel caps.  Also located some 3/32 pop rivets to attach it. Since I don’t know when the inspection will be, I’m just going to put 2012 in the date box; this field isn’t even required.

Then I took a look at the top hose from oil cooler to engine; I think the bend radius on this hose is too tight, and I’ll need to order a longer hose, change the fitting on the engine, and reclock the fitting on the oil cooler, to allow a more sweeping bend in the hose.  It’ll be more in the way of filter changes, but don’t want to take any chances with an oil hose collapsing.

Added a silicone boot to the oil temp sensor wire; more for vibration support of the wire than for short-circuit protection.

Stuck a label on the brake reservoir, indicating what the thing is, and the spec of the fluid it’s filled with.

Traced the spinner diameter and used some geometry to trisect it, in preparation for making the prop cutouts.  Still need to figure how I’ll determine the shape of the cut, not owning one of those curve-finder pin apparatus.

After a trip to the store for more electrical tape, including several bright colors to be more distinguishable from the black colored glass, laid down the first layer of (black dyed) micro mixture on the canopy fairing.  I’ll hopefully sand this tomorrow, then I expect it will take one or two more applications before it’s done.

Sanded & re-drilled the oil door where I had epoxied some misdrilled holes closed.  This is ready for more finish work before riveting the hinge.  Also did some sanding on the top cowling to remove bumps of epoxy and overlap edges of glass fabric.

Sanded the canopy fairing.  Not much of an entry for 3+ hours of work, but that’s the size of it.  Hoped to lay up the first round of micro filler so it could be sanded tomorrow, but it got too late.

More fun with cowling to start the day: added some glass to a spot in the nose of the upper cowling that was thinned out by sanding, and laid up a couple plies at the sides of the oil door (+ peel ply).  Took the extra epoxy and squeegeed it on the inside of the top cowl.

Taking a break from fiberglass work, I filled the brake system with fluid.  This was pretty easy with the use of the brake bleeder tank I picked up from ATS, which came with the correct bleeder fitting for the calipers.  I filled up the tank with fluid, attached a NPT-to-hose-barb fitting to the brake reservoir in place of the cap, with a clear nylon tube to the empty fluid canister, and pumped away.  Once a stream of uninterrupted fluid had flowed out of the reservoir, I switched sides and repeated.  No leaks apparent, but I still need to climb in and test the system under pedal pressure, as well as check the operation of the parking brake.

Back to work: spent considerable time sanding down the fillet of Sika at the canopy base.  I decided to do a layup of glass here, for a number of reasons.  To enable that, I pared down the Sika fillet, exposing some plexi above it, and some aluminum below it.  Scuffed everything up well, and laid out edge lines with electrical tape.  I cut a ply of “Rutan Bid” glass cloth, and a ply of a cloth with a tighter, denser weave to place on top of that; both were curves cut on a bias, for a smooth fairing with no ply overlaps.  Mixed a batch of epoxy with added black colorant, and laid up both plies of glass, plus a layer of dacron peel ply.  Today was the first I’ve used the peel ply, so we’ll see tomorrow if I did it right.

One more little item on the list, plugged into the VP-X and updated it to the latest firmware version.  The cheap USB to RS-232 converter I bought for $9 is junk and won’t install on my computer, so I haven’t been able to service the APRS unit.  I’ll borrow the one from work that I was using before, and find a better one to get for the shop.

Also looked at the fit of the Crow crotch straps, which look like they’ll fit into the brackets without trouble.