Joshua's RV-9A Project

Scraped and sanded the filler which was applied in the previous session.  Shaped the rudder top TE to match the rudder skin.  Ready for more spraying when I find the time.

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).

Sanded the empennage tips to smooth the micro filler I added earlier this week.  Also the empennage fairing, which looks decent, though I’m sure there are some ppinholes I’ve still missed.  Fit the rudder top back to the rudder, in order to sand the big glob of micro I put on the nose of that tip; the side corners of the tip were not even with the rudder skin, aand they now are.  Now I’ll need to fill the air bubble holes in that area, but that should be easy enough.  Hopefully will spray primer on some of this stuff over the weekend.

Moving to the engine, I was able to knock a couple minor things off the list.  Added a safety clip to the oil drain valve, that would prevent it from coming open unintentionally.  Also, removed the upper oil cooler line, changed the 45* fitting on the engine to a straight, and reclocked the 45* fitting on the oil cooler.  Then replaced the removed line with a longer one, to add a bit more flex, and ensure that the minimum bend radius of the hose is met.  Thanks to Tom at TS Flightlines, who turned around the order for this line in one day (and previously made all the other engine hoses to my specs).

Milestone: 1600 hours in this session.  We’ve now reached the low-end of my estimated total hours range.

More work on the empennage tips: drilled & countersunk the rudder bottom, then removed and sanded.  Applied micro to spots on several of the tips, to fill in divots along the joints in factory layups.  Put a blob of epoxy around the rivnuts for the rudder light, to make that a little more stable.

Pushed micro into the voids and large pinholes in the empennage fairing; this will likely still need another coat or two of epoxy or filler and plenty more sanding before it’s done.

On the right hand heat control, replaced the black-on-white label with a white-on-black version.  The P-touch labeller’s smallest text is larger than the size I was able to print with the Rhino, though, so it’s a bit out of proportion with the knob.  If I can find white-on-black Rhino tape, I might replace it again someday.

Slid a piece of nylon expandable sleeveing over the trim servo wires that protrude from the left elevator, for extra protection against chafing the wires.  Secured with heat-shrink on the end.

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.