« Posts tagged fiberglass


7 hours.

Put the pants on, one leg at a time.   I’m about to head back into my regular work schedule, which means days will become weeks.   So a task that will take a couple of days, will become a couple of weeks, because I’ll only get to it on weekends.  And the fun part coming up:  Wet fiberglass!  But this is what I got done today:

People’s exhibit A:  The right side wheel pant with the intersection fairings test-fit.



Left wheel pant.IMG_1966



Getting there.   Today was all about installing the mounting hardware for the fairings  Since we did the tweaky measuring stuff on Friday, today was all about just putting everything together.   Lots of platenuts to replace the clecoes from the position-locking drill ops.   But it is actually pretty cool how sturdy these things become once they’re put together and installed.   They’d better be.   They’re going to get the crap beat out of them.

Next is the wet work.   The intersection fairings will have to be taped on, then have a couple of layups of glass put on them to thicken them and make them conform to the exact shape of the fuse, gear leg fairings, and wheel pants.  I’m still working out the best way to do this, but I think it’s a two-day job.   One side per day.    Then the whole kerbang comes apart and I take the parts home and paint them.

Back to Project Status

IMG_19596 hours.

About 10 hours into Phase 1 testing, and so, time for the first oil change, among other things. Have I mentioned I love flying this airplane?   I’ve been flying all week and not blogging much, because I’ve been learning the airplane, how it flies, how it feels.  I can report with great accuracy that gyroscopic precession is a bitch:   If you try to lift the tail too fast, the aircraft will quickly be pointing at whatever is to the left of you.

I’m updating and rearranging the order of things in my checklists, based on where the task is spatially in the cockpit.   This is just good UX design, but like anything else, you work out the best workflows through usage.   For instance:  Put the flaps up before takeoff.   Yes, I know, this should be a post-landing task, and it usually is, but it doesn’t hurt to have it on the runup checklist before RPM to 1700.

The autopilot is more or less dialed in, but it still jitters a little bit.  This is unsettling and needs fixing, but that can happen later.  At least now it doesn’t pull a divergent oscillation in bank.   My fuel flow fix works as well.  I’m now reporting a burn rate consistent with what I expect for a given RPM or MAP.

Day before yesterday, I took a flight to Santa Paula to get fuel and spent a little time buzzing around the Ojai valley.  That’s where the above pic is from.   But following that flight, I decided to take a run at tweaking the idle, which is still al little rough down in the 750’s.  Last time I messed with it, I set it richer to cure the somewhat terrifying issue of it stumbling when advancing from idle to high RPM.   I think I went too far in that direction because since then, it’s run rough at idle and has been a bastard to start when hot.    The hot start is a known issue with FI engines, but even with the proper procedure, it’s difficult, so an adjustment had to be made.   This took the better part of an hour and a half, and the engine has to be hot when the adjustments are made.   This is why I have a nice burn on my hand from trying to get a wrench into the space where the idle adjustment arm is.   I’m still not ballsy enough to adjust this thing with the engine running.  That’s just not going to happen, especially when the exhaust pipes are still hot.   It’s amazing how fast ss exhaust pipes cool, but you don’t want to have a forearm laying on one when they’ve got hot gas blowing through them.

I was going to go fly again, but the wind put the kibosh on that idea:  14kts gusting to 20kts, although right down the runway.  I was too chicken to try to fly that, although I could have probably done wheel landings and i’d have been OK.  Better safe than filling out FAA forms over the wreckage of a balled-up airplane and a bunch of broken runway signage.

But yesterday saw the return of 313TD from aircraft to project.   David and I did the cutting and measuring of the wheel pants and gear fairings.  This is way more difficult than it has to be: You have to take the weight off the gear so you can align the wheel pants and gear fairings in trail.   Fortunately, the local airport mafia purchased a surplus forklift for a couple hundred bucks, and doubly fortunate, Dave knows how to drive one!


I didn’t snap a lot of pics during the actual process because we got busy and stayed busy.   We first jacked up the plane on each side to install the wheel pant brackets, and took the opportunity to bevel the brake pads in an attempt to stop them from groaning during taxi.    Then we used the forklift to lift the airplane by the motor mount just high enough to get the weight off the wheels and the bend out of the gear legs.   Then there was a lot of crawling, measuring, and marking to find the centerline of the wheel parallel to the centerline of the aircraft.   We drilled the aft section to the gear brackets once we had everything lined up.


It’s amazing how hard it is to find a 1″ block of wood in an airplane hangar, but 3/4″ PVC, no problem.  Short sections of that were used as spacers on the vertical to give the 1″ clearance required for the wheel pant.

Then we did the loop-of-string method to insure the gear leg fairings were in trail.   No drilling done there, but marking the position on the gear legs got us what we needed.

This whole process required making as much space in the hangar as possible, so we had to shove the Luscombe outside and move a bunch of stuff around to accommodate the forklift’s dance moves.


The yellow chocks are where the forklift wound up to put the tine with a hole in it directly above the engine mount.

Of course, all this means that the aircraft is down until the fairings can be installed.    This is necessary anyway because I need to do an oil and filter change and a thorough under-cowl inspection.   Fortunately I can do some of the fairing work at home, like paint.   But what’s left is the onerous, fiddly part: glassing in the intersection fairings, then trimming and priming the pieces.   When that’s done, I should be able to bolt it back together and go flying some more.

“Twas the Weekend Before Christmas, and All Through the Hangar…”

4 hours.

“Not a creature was stirring, save this rivet banger…”

This encompasses Saturday through Monday.

With the holidays in full swing, the schedule gets a little weird, but better, because I have a few days off.   I’m keeping a decent balance between building, home obligations, holiday festivities, and the occasional video game.   I’m also coming to terms with the fact that the endgame for this project is approaching rapidly, or so it seems to me.   Last weekend, I’d started on the gear leg fairings.   This weekend, I pretty much got them done.

The most important thing with the gear leg fairings is to build them without any twist in them.   They come taped together from the factory, but Van’s fiberglass is usually so crappy for fit, I didn’t trust them.   The way you verify no twist is to put the leading edge on a flat surface and using a square, insure that both trailing edges line up.   Once that’s done, you can use the full-scale template cut from the plans to mark all the cut lines.   Easier said than done, though.  You really need two squares, one for each end, and another pair of hands, or at least a boatload of tape.   But I found a solution in our hangar that worked very nicely:

IMG_1710That brass thing is a piece of channel from one of those godawful floor-to-ceiling mirrored sliding doors, usually found in cheesy SoCal apartments that saw their last renovation some time before Saddam Hussein rolled his tanks into Kuwait City.   But it makes a very nice, very straight jig for lining up the trailing edges of the gear leg fairings.   Not only that, it provides an excellent platform for match-drilling the hinges.   Some of you are looking at this and saying “hey, those are the wrong size hinges!”  Yes they are.   But it’s what I had.   I used up all my 1/16″ piano hinge on various attempts at the cowl.   If it should come to pass that these hinges cost me knots and fuel, I’ll change them out, but at this point, I want to be done.


A selfie, checking the alignment of the hinge.

With those done, I could check out the fit of my intersection fairings.


Upper intersection fairing fits, sort of.   It needs some work.   It’ll also need to be taped into position to hug the contour of the fuse and cowl, and then a couple of layups on top of that.   After that, it gets trimmed back to where it’s supposed to be.   Van’s fiberglass may be crap, but it’s better than mine and it sure beats fiddling around with modeling clay.

Monday was all about tying up as many loose ends as I could before starting on the wheel pants.   This meant, among other things, getting as ready for the inspection as possible.   I attached the ‘EXPERIMENTAL’ sticker to the roll bar:


This is a bit redundant because the baggage bulkhead cover that came with the interior has it embroidered into the leather, but that won’t be installed during the inspection.   The canopy frame covers this one up when the canopy is down, but I don’t think that matters.   If it does, those stickers are cheap.


This is required by the Feds to be in the airplane in plain view of the occupants.  It’s like a magic amulet to ward off the unadventurous.

Left Gear Leg

Left Gear leg

Left Gear leg works much the same way.

After this, I spent some time doing odd jobs.   I safety-wired the tailwheel chain hardware, then moved to the cockpit, where I zip-tied the wires made loose by the magneto troubleshooting and the addition of the OAT probe.    I also attached bolts in the center section per Van’s SB 12-08-14.   Apparently enough people forget this step that Van’s thought it merited a Service Bulletin.   Guess what?  I forgot it too.   In addition to the close-tolerance bolts that hold the wing spars to the center section, there are two on each side that secure the center section to the vertical bar on the wing spar.  These need some AN4 bolts in there to lock things down.

Part of getting airworthy is checking all the relevant SB’s and AD’s to make sure you don’t have anything hanging in the breeze that might kill you.   The rules on experimental aircraft and AD’s are fuzzy, and are interpreted by various people in various ways, because different sections of the FAR’s appear to contradict each other.    But the safe thing to do is check for AD’s and SB’s that apply to your stuff and fix them if you find any.   If I hadn’t gone through this process, I wouldn’t have found those missing bolts and the inspector would have.

When I moved on to the engine, I discovered some oil running down from the spacer on the right mag and at the oil drain fitting of the #1 cylinder.   This was alarming enough to merit a quick engine test.   I cleaned off the oil and wheeled it out to start up, to verify that the oil was new and not left over from the last time I had to loosen them up to get to one thing or another.

I did a quick runup and brought the cht’s up to operating temperature, but even with good, timed mags, it still stumbled off idle.   Advancing the throttle slowly would bring the RPM up, but moving it smartly, like I would for takeoff, killed the engine.   After consulting VAF and then my AFP manual, it looks like my idle mixture is set too lean.   This will need to be corrected, and I can probably do this tomorrow.  The good news is that I didn’t see any new oil in the spots where I found the drips, so it looks like the oil around the mag spacer was from when I had the mags off, and the oil from the #1 drain line is from the time I had to undo the fitting at the cylinder head to get at either the bottom spark plug or the EGT probe.



Gear Leg Fairings Continued

6 hours.

I found my missing length of piano hinge (hidden inside a piece of PVC to keep it from getting damaged), and took it and my intersection fairings up to OXR to see what I could get done.   I got up there and spent a lot of time pondering the instructions and plans.  I spent a lot of time doing that because this is real work about to be done here, and it involves fiberglass, and the cutting of things that affect the flight characteristics of the airplane.

The first thing I did was put the wheel fairing attach brackets on.   This is a stupid process if ever there was one.  I had to wrangle the engine hoist from down at the EAA hangar, walk it halfway across the airport, then lift each side of the plane  by running a strap around the engine mount so I could get the wheel off   I’m not shelling out a couple hundred bucks for some weird attachment, this seems to work just find.  With the wheel off, I could attach the bracket.

The gear leg fairings, on the surface, are not that complex.  They’re teardrop-shaped covers for the round gear legs.  The only tricky part is that they have to be built with no twist in them.   There’s a full-scale section of a drawing that needs to be cut out and used as a template.   This lets you know where you can cut the fairings, and the fairings are the same ones used for all Van’s aircraft except the -8 and the -8A.   They are attached by means of a couple of hose clamps and secured by a piece of piano hinge running up the trailing edge.   So they have to be cut straight, then there’s the hinge installation, then the alignment to the fuselage.   I got one part of one leg cut, and had to move brake tubing out of the way and cut clearance divots where that wasn’t feasible.

Other time was taken up by moving the late Jim Ayers’s RV3 (with the Walter LOM engine) out of the EAA hangar and down to his private hangar waaaay at the other end of the airport.   Ron and I rigged up a way to lash the tailwheel to one of the forks of the old propane forklift and he towed it, driving backwards, really slowly.   I followed him in his VW.  After we got back from that, we went for a ride in the Pacer.

Starting on gear leg fairings and wheel pants

6 hours.

My pre-molded intersection fairings arrived from Van’s this week, but of course I forgot to take them up to the hangar.    The last major bit of fiberglassery is the landing gear stuff, so I tried to get started on that today.   There’s a .063 plate that bolts on to the brake caliper and its job is to hold the two halves of the wheel pants together, on each wheel.   I made them, cut all the spacers, and installed them, then took them off, anticipating that I could just put them  back on as needed. But it’s impossible to access the bolt head on the inside of the brake caliper without taking the wheel off.   I made two attempts to bend a 7/16 wrench 90 degrees at the open end, one resulting in a broken wrench, the other a wrench with too wide a bend to fit inside the rim and access the bolt.

So I figured taking the wheel off would be the best option.  I searched the hangar in vain for a floor jack.   Those guys don’t have one.   The engine hoist I used before is down in the EAA hangar, but it was all locked up and I couldn’t get to it.   So that was out.

I did get the plans and the manual out so I could begin working on cutting the leg fairings to fit.    That didn’t take long, so I went up to the aviation department of O’Reilly Auto parts and picked up another tube of red RTV.   I finished the front baffle bead and the left mag duct, and also isolated a couple of things from chafing via the RTV Blob method.

Cabin heat done.

6 hours.

I spent a little bit of time installing a little air conditioner in the window, the one we’d previously taken out of the guest house bedroom and put in the dining room window while Shelley makes a wedding dress for a friend of ours.

Putting it in the shop window was brilliant… Nice and cool and comfy, in what passes for a heat wave here near the L.A. beaches.

Once that was done I worked on the alternate air for the snorkel. They have you glopping up the interface between the galvanized steel opening hardware and the fiberglass snorkel with a mix of flox and resin. I guess this makes sense, but it seems kind of half-assed. Once that cures, I can sand it smooth and call it done. The snorkel won’t be done-done until I get the air filter opening pro-sealed in, but then it’s another thing I don’t have to worry about again.

With the goop on the snorkel setting up, I wanted an easy win, so I worked on the cabin heat cable. The plans for this thing aren’t real clear about how you’re supposed to route the cable through the cabin, but I worked it out. The knob sits to the right of the throttle quadrant, so the passenger can easily get at it. I also wanted to do this so I’d have an inkling of what I’d be looking at when installing the alt air cable, which is another Bowden-type cable like the cabin heat. This type of cable is similar to a bicycle brake cable, or if you’re old enough to remember, a choke cable.

Mostly a non-issue. Cabin heat door opens and closes with push-pull. Sounds done to me.

Cowl surfacing, part 2.

6 hours.

Before I knew anything about fiberglass, I figured the pepto-pink Van’s cowl was pretty much the norm. It’s not. The Van’s cowl is shite. You’re supposed to fill in all the pinholes (and the whole thing is mostly pinholes) by rolling on straight epoxy, then squeegeeing it off. 3 coats go on like that and theoretically, the pinholes are filled in.

The reality is far from theory. What I’ll have to do now, if I want this thing to be even remotely smooth, is to squidge on a layer of micro slurry. Not the paste used for building up a shape, but enough to fill in all the divots. Once that’s done, I’ll be able to sand it smooth, then seal it with another layer of resin.

Or, I could take it to a body shop and have them do it. I need to be very careful not to bust the 51% rule, though, since I got the quickbuild kit to start with.

So the third coat of resin is curing right now, and should be ready for sanding tomorrow.

Since I was in fiberglass mode, I finished the cutout I had to make in the snorkel to allow it to clear the alternator. This is also curing, and should be done enough to permanently install tomorrow.

Aside from that, I reworked the fuel feed line so it makes a little more sense and doesn’t bend at such an extreme angle on the input.

Cowl and foam

4 hours.

Yesterday I glued the sub-ramp I made the day before to the cowl. Today, I shot my marine foam into the space underneath the ramps in preparation for glassing in the sides and blocking travel of high pressure air through the spaces underneath the ramps to the low-pressure area to the sides and below the baffles.

I may have used too much foam. It just keeps growing.

Tomorrow I’ll carve out the excess foam and glass in the tunnels.

I also took a crack at filling the area around the oil door. This might turn out badly, but it’s just resin and micro, so I can always sand it off and start over.

Cowling ramps

2 hours.

This is two hours of puttering over the last several days. I go the cowl ramps glued on, and tonight I made the contoured part that interfaces with the governor baffle. Next is to fill the cavities under the ramps with boat foam, shape them, then glass them over.

Gluing the ramps on turned out to be more or less a non-issue, but I did have to take the front baffles off, which is a PITA.

I got my ignition harness back from Bill’s Air Center. That was only $80 worth of stupid, so I consider myself lucky. Oh, I didn’t tell you about that? OK. I was pulling on the wire end of one of the starboard plug wires at the harness cap, for some reason, and it slid out of the casing. Plug wires work like a Chinese finger trap. The outer shield expands or contracts depending on where the tension is, so it allowed a bit of wire to slide out of the casing. One thing led to another, bad went to worse, and the next thing I know, the whole wire is in its separate components on my bench.

After a frustrating couple of minutes, I resigned myself to taking it up to Bill’s Air Center at SMO. Bill’s a great guy and he’s been there forever. They fixed it, but said it was a major headache to source all the parts, since Skytronics doesn’t actually sell them. They want you to send your harness back to them for repair. Phoo on that. Anyway, it’s all better now.

Baffles 13

5 hours.

Lucky 13. This baffles thing is second to none the worst, most vexing part of this build yet.  However, I did make a lot of progress this weekend. I got the airseal material trimmed, for the most part, although I suspect I’ll have to iterate the left front a bit, the part that goes around the governor. This is no end of head-scratching and puzzlement. Today I was actually able to drill the airseal material to the baffle sides, which is a big step, and with the exception of what I just mentioned about the front governor, the top cowl seems to seal all the way around, which is a good thing. Never having built an airplane before, it’s hard to tell if I’m overthinking a problem. The key is to keep focused on the end result desired, and solutions will appear. On this particular task, they take their sweet time doing so, and this is the one task on this build where I’m not able to stand back and go “yeah, that’s awesome.” Instead, it’s something to be gotten through, like a prostate exam or tax forms.

I’ll post as much of a photo story as I can in a later entry, but I didn’t take a whole lot, and part of the reason for that is that it’s really difficult to see anything inside the cowl with all the parts installed, let alone jam a camera up in there and shoot comprehensible pictures.

There are also a number of things that need to get finished before this can be called “done” so I’ll list them here and hope to get at them this week.

The pain in iteration comes from having to put on and take off the baffles. This is a time consuming process, and needs to happen several times before all the finishing touches can be done, but it’s not a good idea to install things permanently because depending on various factors they’ll just have to come off again. So here’s a list of unfinished business, in no particular order:

  • Make tab for left front lower ramp to close off gap near engine case.
  • Drill rear bracket to rear baffle
  • Make/install fasteners for front/rear side baffles
  • Drill ducts for alternator and magnetos
  • Drill/install spark plug wire grommets
  • Proseal corners of snorkel at the filter bracket
  • Finish making front left baffle seal sections
  • Trim cowl for lower left inlet ramp
  • Rivet oil cooler reinforcing bracket to baffles
  • Drill/install oil cooler doubler and bracket
  • Deburr baffle seal rivet holes
  • Pop-rivet baffle seals to baffle metal
  • Glue/fiberglass top cowl inlet ramps/seal inlet ramp sides, shape ramp interface
  • Permanently install prop governor, gasket and all
  • Recut governor/front left seal material
  • Make/install lower cowl inlet seals

It’s endless, I’m telling you.  But with this out of the way, it’s time for plumbing, wiring, and control cables.  When that’s done, I’ll rivet the top skin on, put the canopy back on, and finish the interior.  After that, it’s time to go to the airport!