(page 13-2) Wings continued

After priming the mating surfaces on the 20 rib-attach angles, said angles had to be riveted to the spar webs using pulled rivets (thankfully).  This would involve my favorite tool, the pneumatic puller. Problem was, the

rivets are very close to the angle flange, necessitating use of either the little wedges which were constructed as the very first step in the entire build (can't find them) or the tool shown in the first photo (wedge with a handle).  Using the wedge tool and flexing the angle a bit allowed all the rivets to be pulled without reverting to the manual riveter.

Since the rivets had to pass through the spar web as well as the angle itself (and sometimes another angle on the opposite side), hole alignment was an issue.  The custom hole-alignment tool (Vice-grips holding a 1/8th-inch drift whose tip I tapered) solved the problem, as usual. I prefer this to using a reamer or #30 bit, and I've found very few cases where this wouldn't work.

The next step involved machine countersinking 120 degrees all of the #30 holes on the slanted flanges of the stub spars.  Even though a countersink cage is used for this, I've always found it hard to get exactly the same depth on countersinks.   Van's suggests drilling a 1/4-inch hole in a scrap piece of aluminum and using this as a quick gauge for the larger diameter of the

taper, which I did.  It's still hard to make them identical.  Apparently, dimples in the leading edges of the wing skins fit into the countersunk holes.

The stub-spar doubler plates get riveted to the stub spar webs with 1/8th-inch solid rivets, requiring use of my Main Squeeze and jeopardizing my recently repaired rotator cuff.  Hole alignment again required a fair amount of effort.  The holes with clecos get left open at this point.

The six #40 holes within the inboard rounded portion of the stub spars get countersunk 100 degrees on both faces for "double flush" solid rivets.  Double flush, of course, means the countersunk rivet is squeezed using a flat set until the shop head is flush with the surface of the aluminum, leaving nothing protruding on either side.

The semester is officially over.  All grades have been turned in and, following last Saturday's commencement ceremony, a fresh batch of mechanical engineers has been released into the wild.  Theoretically, I should now have plenty of time to work on the airplane.  The antique car is, as usual, taking part of my time.  The engine for it is going together well as I continue to hemorrhage money.  Should be on the dyno within the week.

(page 13-02) A wing and a ....swear(word).

Or maybe a prayer to the god of aircraft construction that I'll do a better job inventorying the parts when the kits arrive.  With the empennage and fuselage kits, I inventoried essentially all the sheet metal parts and most of the bags, without always looking at every single part in each bag.

 I didn't count all the bolts, nuts, washers and certainly not all the rivets.  My thinking was that my time was better spent building, and if some small part was missing, I'd order it.  The small parts are cheap, and priority mail gets me the parts from Van's to North Carolina in two to three days.  This method worked surprisingly well, with only a couple of nuts or nut plates missing.  When the wing kit arrived, for some reason I didn't inventory anything.  I simply spread the various parts around the garage wherever I could find space.  I don't know why I did this.  Step one of the wing section of the build manual called for cutting apart an angle about two feet long into 20 smaller angles and putting these aside for later use.  You guessed it.  I couldn't find this angle.  Over the next three days, I spent at least three hours searching for the part.  On day two, having abandoned hope and cursing myself for my sloppy inventory technique, I made the decision to reorder but, fortunately, put it off for a day.  On the next day, I found it cleverly hidden out of sight on a box beneath a table.  I had to get on all fours to see it!  Inventory technique exonerated (except for the wasted time).

Step two called for cutting apart a stiffener plate.  Couldn't find it for two days.  The moral of this story is to do a proper job with the inventory and avoid this anguish.  With the fuselage kit, which has more parts and more different parts than any other kit, I made a notation on the inventory sheet telling where each part or bag was put.  I named the various cabinets and sets of shelves, then put that name next to the checked-off part on the inventory sheet (being an engineer, I'm surprised I didn't number them instead of naming them).  With the wing kit, I can't even find where I put the inventory sheet!  I am, at this moment, taking a solemn vow to do a better job with this.

Step three of the wing kit involved drilling and tapping four 5/16th-inch holes for the tie-down rings in the wing spars.  To better explain my fear of this, realize that the wing spars arrive as multiple anodized plates and angles beautifully riveted together.  Each spar is a thing of beauty.

 Doing anything to it makes me nervous, conjuring up visions of a vary large check which would be required to get a replacement.

The drilling and tapping went well.  As shown, the back of the tap handle accepted a 3/8th inch ratchet drive, which greatly facilitated the task.  Boelube was applied to the tap initially, and for every two rotations clockwise, I rotated the tap one rotation counterclockwise to clear the chips (a technique I learned as a student working in a machine shop).

You may be wondering why both top and bottom got tapped.  Best I can figure, it's to allow a hard point on top of the wing if a person is willing to drill the wing skin to expose it.  I'm thinking ahead to somehow using these to support the wings from the ceiling joists once they're finished.

(page 29A-08) Map box

Building the map box requires, among other things, match drilling holes into piano hinges (my 233rd favorite thing) from pre-punched holes in the box walls and map box door.  A seeming misalignment after initial drilling and clecoing, a result of the match-drilled holes being not perfectly parallel to the door edge, turned out not to be a problem.

The trial fits of the Camloc fitting into the half-inch hole (produced with a step drill) seemed at first impossible for two reasons: 1) getting the T-shaped end of the Camloc through the hole required a precise angle, almost like a puzzle, and 2) extending the T-shaped end of the Camloc with finger pressure in order to get it through the hole was, to put it mildly, difficult.  Then it occurred to me that the cleco pliers worked perfectly for this.  Problem solved (second picture).

Attaching the map box to the right instrument panel involved squeezing some AN426AD3 rivets in holes which could be reached with the Main Squeeze and pulling CCR-264SS-3-2 in holes which couldn't be reached.  The pulled, flush rivets ended up, as usual, not quite flush.  As was called out in the plans, I countersunk the holes to accept the AN rivets (100 degree), all the while wondering if the countersink should have been 120 degrees as is the case with other flush, pulled rivets.  I couldn't find the answer.

 I did cure the lack of flushness (yeah, I know it's not a word) by tapping the rivet face with a 3/16-inch drift (which fit the rivet exactly) while placing the reverse side against a solid surface.  Worked perfectly.

After reading a post on the forums yesterday, I realized that I need a different left-side instrument panel and center panel, along with a four other parts already installed (more drilled-out rivets).  This is a result of Van's switching to the Garmin radio and built-in intercom.  I'm assuming they'll send them free, since the parts they sent with the fuselage kit are wrong.  They're usually good about such stuff, and I'm a bit surprised they didn't send them already.  I'll call the Mothership tomorrow to get this resolved.  I'm so close to finishing the fuselage kit I can taste it.  I'm expecting the wing kit to be cake by comparison.  Still have no idea where to store the wings when they're finished.

(page 29-05) FlameMaster goo

As the firewall is completed, all the rivets which penetrate it must receive a blob of special sealant.  Apparently what used to be ProSeal (fuel tank sealant) is now CS1900 FlameMaster.  I had used the

smallest available amount earlier (~1 oz) when attaching the firewall shelf, but opted for for the next larger size (~17 oz) for this task since it allows use of a caulk gun.  This worked well, but it ain't purty, as my friends used to say growing up in rural South Carolina.  As long as it masters any potential flames, I don't care about appearance.  In addition to rivet heads, there are various tooling holes and seams that must be covered, but this size was more than enough.  Rather than the CS1900, many builders are opting to use 3M Firebarrier 2000+ which doesn't have to be mixed, and is similar in application to silicone seal.  With the CS1900, the catalyst is mixed while entirely enclosed within the main tube (50 strokes of a plunger), reducing the chance of getting it on skin.  I started out using gloves with several hundred ice cream sticks at the ready (they don't sell them in small batches), but quickly discovered that I didn't need either.  I may have used a total of 5 sticks to smear the stuff around in a few spots, but a dabbing motion with the tip of the tube seemed to work well.

Making the substitution of Firebarrier 2000+ for the FlameMaster my constitute a violation of the E-LSA

edict to build exactly, rivet-by-rivet like the ASTM conforming prototype.  Don't know.

The combination battery box/oil tank holder, including the service bulletin stiffener kit, went smoothly.  I pulled all the rivets by hand (though a few could have been done with the pneumatic puller) and was initially convinced that some of them would be impossible to reach, but happily I was wrong.  Absent any guidance from the build manual, I usually try to pull all the rivets on a particular surface in the same direction, simply for appearance.  That was impossible here.

Much of my lack of progress lately can be blamed on my antique car.  Simply rigging a throttle cable to operate a throttle body at the front of the engine rather than a carburetor in the middle of the engine is an incredible PITA.  Seems that it should be simple.

(page 29A still) Longeron imperfections haunt me again

With the panel base, panel ribs, stack angles and other assorted bits riveted together, it was time to cleco the assembly to the firewall upper and then match-drill the longerons.  The edges of the panel base, it was stressed in the build manual, should be parallel to and, I deduced, flush with the longerons.

Didn't happen.  The guy doing the Homebuilt Help video had the same problem, and I did as he did:  wedge a board between the longerons to spread them a wee bit.  Anything that requires drilling the longerons strikes fear in my heart.  I can't bear to contemplate what I would do if I trashed the longerons at this stage of the build.  Probably melt the whole thing down and sell it for scrap aluminum.

The procedure I used was as follows:  Starting with the aft-most edge of the panel base, spread longerons until alignment occurred.  Match drill and cleco one hole.  Press the forward edge of the longeron in until aligned, drill and cleco forward-most hole.  Match-drill the holes between clecos.  This worked well on the right side, not so much on the left.  The forward, left edge misses being parallel by about 1/32 of an inch.

Yeah, yeah, I know.  We're not building the space shuttle.  Still, it's irratating.

I am pleased, however, to see these various pieces of aluminum continue to coalesce into something that resembles an airplane.  I should be able to start the wings next week.  Still don't know where I can store them when they're built.  Where there's a will, there's a way.

(page 29-A) Wait....what?

Overall, I think the build manual is quite well written and the CAD drawings are terrific.  However, I found the words describing what needed to be done to the canopy ribs, doublers, attach angles and panel base to

be, uhh..., challenging to comprehend.  The Homebuilt Help videos actually seemed to contradict the manual.  Turns out, there was a reason for part, but not all, of the confusion.

For the canopy ribs (shown), I sort of figured out which holes were supposed to be machine countersunk rather than dimpled, though the machine countersinking never made complete sense considering the thickness (or lack thereof) of the aluminum sheet.

Update 9-8-13:  Just discovered that the bolt holes on the aft flange don't get dimpled (had to un-dimple them with a flat set).  The bolt holes on the other flanges do get dimpled.  The rivet holes in all flanges get machine countersunk.  The rivet holes in the web get dimpled.

The panel base was another story.  It was obvious that the piece delivered with my fuselage kit was different from the picture in the build manual.  An e-mail to the Mothership confirmed that I had been shipped an older, pre-Skyview, part, which I now have to modify.  Getting the correct part would mean that all the dimpling and riveting I had done to the part I have would be for naught.

I'm blaming my recent lack of progress on having to teach a new course this semester.  It's been a while since I actually had to prepare lectures from scratch.  I had forgotten how many hours of preparation are required before I can stand in front of the class and speak in a semi-intelligent fashion for an hour and fifteen minutes.  I told the Dean of Engineering that he is responsible for delaying my first flight by at least two months.

Pilgrimage complete for 2013

Incredibly, I made my 25th trip to Oshkosh this year (my sticker collection is missing only my 1980 trip).  Things seemed different this year, however.

 Due to the sequester (an idea invented by the current administration but never expected to actually happen) the military was not allowed to attend.  The space formerly known as AeroShell Square (now I think it's called Phillips 66 Square) was quite deserted compared to earlier years.  I missed them.

The number of planes attending the show was supposedly in excess of 10,000.  I believe this, but I'd say there we fewer show planes.  There were hundreds of RVs and I saw approximately 10 RV-12s, including the Eagles Nest planes.  I was able to wrangle about 15 minutes of stick time in a -12, the third time I've been able to fly one.  I need to finish the build and start flying.  I'm ready.

The upper firewall is nearing completion (I hope).  The next step calls for sealing the rivets and holes in the firewall with CS 1900 fire barrier, which I dread.  School starts tomorrow, and I'm trying to figure out where the hell the summer went.  I had planned to have the wings finished two weeks ago and I haven't started them yet.  Also, I don't know where I'll store them when they're finished.  Space is a major problem.  In the width of the two-car garage where I'm working I have a work bench, a table where I'll build the wings, the fuselage (shown), a car, and a motorcycle.  Something's gotta go.                          

(page 29A-02 + page 54-01) Upper firewall + stiffener kit

The upper firewall fabrication involves lots of nut plate installation and match drilling of piano hinges.  Much of the drilling is through the stainless steel firewall itself, a bit harder than the usual aluminum.  A drop of BoeLube on the bit helps with this.  I included the

"optional" stiffener kit installation with the firewall since they connect.  As might be imagined, the stiffener kit is much easier to install at this point in the build.  The instructions are written as if it's a retrofit, so all of the rivet removal described was avoided.  The kit does involve drilling 40 or so holes in the side skin, some from the inside out and some from the outside in.  At this stage in the build, I approach the drilling of holes in the skin with fear and trepidation.  Screwing the skin up would be unimaginably bad.

Oshkosh is finally here!

I accomplished nothing on the build today, devoting the entire day to getting ready to leave tomorrow morning at the butt crack of dawn for a week at Oshkosh.  As we did last year, we're having a get-together of RV-12 builders.  At last count, 42 people are scheduled to meet on Tuesday.  I'll get a group picture and post it.  I've been listening on the web to ATC for KOSH (tower for 18-36) and I'm pumped from hearing all the planes land.  Tomorrow afternoon, I'll be sitting in the grass beside the runway with radio in hand, witnessing it in person. Can't wait.

(page 24-05) Less like a boat, more like an airplane

I had been looking forward to attaching the rollover assembly primarily so it would start looking more like an airplane, and with the addition of the rear bulkhead the effect was even more pronounced.  The look really

got me fired up.  The machined aluminum pieces which bolt to the lower fuselage and are supposed to slide into the rollover structure didn't fit and required a bit of work on the belt sander followed by the ScotchBrite wheel.  The rule of thumb on this kit is supposed to be "if it doesn't fit, you did something wrong."  Not here.  Considering how the roll bar is constructed, I was not particularly surprised.  I probably had to take ten thou off the width of the machined pieces.  Fits great now.

The only other anomaly encountered was the channels which get riveted to the bulkheads.  The build manual shows three snap bushings being inserted into the channels, but my channels had only two holes.  I contacted the Mother Ship and was told to break out the step drill and make a new hole.  This would have been easy had I not already riveted everything together, as called for in the build manual.  Once again, the Tight Fit Drill Kit to the rescue.  I was able to drill a quarter-inch hole and then expand it to the proper diameter with a cutter (attached to the Tight Fit).  All is well.

The build manual calls for attachment of the tail cone soon, but, as many builders do, I'm postponing it.  With the tail cone attached, the thing becomes quite unwieldy. I'll continue with the upper fuselage construction, followed by the wings.  I can't imagine where I'll put them when they're done.  Space is a problem.

(page 24-02) Roll-over structure

The two curved channels and two straps that connect them arrive pre-punched to #40 and must be drilled to #30.  The four parts must be clecoed together with

the silver clecos, severely straining my supply.  The Isham tool kit which I bought at the start of this project had up to this point had the right amount of everything, and I initially feared the kit was actually lacking in this regard.  Not so.  Doing half of the structure at a time worked fine.  I clecoed every other hole, inside and out, with silver (#40), drilled the exposed holes #30 and clecoed with copper.  This pulled the straps in tight against the curvature.  Also shown in the first picture is my one-handed cleco-pickup tool (a board with holes drilled in it).  There are many times when you're holding something with one hand but need to insert a cleco with the other.

An air drill is an absolute must for this much drilling.  I use the air drill for anything that doesn't require speed control, such as drilling out rivets or counter sinking.

Speaking of which, the entire outer surface, a double row all the way around, must be countersunk.  Since the Lexan canopy will lie underneath these flush rivets (or "lay" underneath as stated in the build manual.  Perhaps they will be producing eggs since they will be "laying."  Van's should be embarrassed by having their grammar corrected by an engineer).

In the jargon of airplane builders a rivet or other item which protrudes slightly above a surface is described as being "proud" of the surface.  I love this descriptive terminology.  Along those lines I am hereby introducing a new term.  A rivet or other item which ends up slightly below a surface will hereafter be described as "ashamed" of the surface.  Since the canopy will lie against these rivets, I counter-sank them a bit more than normal, causing them to end up a bit ashamed of the surface and thereby unable to scratch the Lexan.

(page 23-08) Piano hinge cowling attachment

Anything involving match drilling piano hinges (anti-servo tabs, seat backs, cowling attachment) usually gives me heartburn in one way or another.  These two were no different.  The match drilling is done using the holes

in the side skins as a guide.  The holes go through existing holes in the side skin and stainless steel fire wall tabs, and the new holes go in the piano hinges and an aluminum spacer.  The problem is that once the clecos holding the fire wall tabs to the skins are removed, those two parts are no longer aligned fore and aft, making the match drilling impossible.  To overcome this, I left as many clecos in as were required for alignment during the drilling.  The protruding nubs of the clecos made it impossible for the piano hinge plus spacer to lie flat against the curve, but, starting at the uppermost hole, I removed the minimum number or clecos which would allow me to clamp (see the clamp at the bottom) the hinge plus spacer flat against the curve.  I then drilled and clecoed that hole and moved down to the next hole, repeating the process.  It worked reasonably well, still producing minor heartburn.  The major heartburn came when I managed to drill an unwanted #30 hole in the side skin near the (wanted) bottom-most hole.  The two are very close together.  My first thought was to put a rivet in it, but that would look a bit strange.  Alternatively, I could fill it with epoxy and it would be invisible when the airplane is painted.  I had to invent several new curse words when I discovered what I had done.  None that I knew seemed adequate.

(page 23-06 still) Side skins riveted!

We're drawing ever closer to that milestone in the build of every airplane: the first time the builder can sit in the cockpit and make airplane noises!  I may go ahead and install the seat backs (already completed) just to hasten that day.

Installing those hundreds of rivets in the side skins went mostly without a hitch, although my beloved pneumatic rivet puller did have an uncharacteristic hiccup.  After the first 50 or so rivets it quit releasing the steel arbor after breaking it off the rivet.  I disassembled, cleaned, lubed, and re-assembled the puller head several times to no avail.  Finally, for no discernible reason, it started working again.  The aviation division of Harbor Freight sells a cheapo puller (~$35) which some builders swear by (although it will probably rust before you get it home from the store).  I may get one of these as a backup before I start on the wings, which involve a sea of rivets.  The stiffeners required by the landing gear service bulletin require some CherryMax rivets which none of my regular pullers, manual or pneumatic, would set.  The manual puller made by Cherry (discussed in a previous post) again worked well.  Between those and all the Cleco installation and removal, by forearms got a workout.

Pulled rivet removal technique.  Van's writings on the subject insist that when drilling out a pulled rivet, the steel pin (arbor) in the center should be driven out using a pin punch inserted into the manufactured head, followed by drilling out the aluminum rivet itself.  The thinking is that if the drilling is done with the arbor in place, once the bit hits the steel it will go to one side, making the hole oblong.  Of the thousands of LP4-3 rivets I've pulled, I've had to, for one reason or another, drill out maybe 50.  I've always done it like this:  Using a #30 bit with very slow drill speed and light pressure, drill the manufactured head until the head spins under the bit.  At this point, what remains of the rivet (arbor and shop head) can be pushed out with very little  force.  No pounding involved and no chance of denting the thin aluminum.  I've not had a single problem with this method.

(page 23-06) Return of the porcupine

                                    
This can mean only one thing: My favorite tool, the pneumatic rivet puller, is about to see heavy use.  The skins have to be clecoed in place, including the stiffeners from the landing gear service bulletin, and hundreds of holes must be match drilled through the skins (easy) and through the longerons (pita).

The goodness (or lack thereof) of the longeron bends now becomes obvious.  I had worried about this, but I see now that the longerons can be easily tweaked to fit as the match drilling progresses.

Once the drilling is done, everything has to be taken apart, deburred and mating surfaces must be primed.  I'm still conflicted about priming
and painting the visible interior surfaces.  I can't find the dark grey enamel color I want, and since I'm going with a full interior much of it will be hidden anyway.  The color choice with rattle cans seems to be quite limited.                

(page 54-01) Firewall stiffening kit

                                                                           
The stiffening kit is optional and cheap, and it would make no sense to not do it at this stage of the build.  It supposedly prevents some sort or rumbling noise experienced by some builders. 

It involves installing the diagonal brace shown here on the firewall and two similar braces inside the side skins adjoining the firewall.  This prompted me to go ahead and begin installing the side skins, which I had been avoiding, fearing the skins would make complying with the landing gear service bulletin more difficult.  The landing gear service bulletin requires drilling holes in the center channel using parts in the finish kit as templates.  Problem is, I don't have the finish kit, and therefore can't drill the holes.  All flying 12s had the SB done with the skins on, so I'm proceeding with it.

The procedure for the stiffening kit called for removing the bowl from the gascolator in order to drill out an existing rivet, which meant removing the safety wire I had carefully installed and am quite proud of (experienced builders would find this humorous).

I avoided this by loosening the fitting from the gascolator through the firewall along with removing the AN3 bolts holding the gascolator to the firewall.  I then could rotate the gascolator counterclockwise enough to drill out the rivet.

Massive progress coming soon. 

I turned in grades today for the two classes I taught in summer school (Thermodynamics and Heat Transfer).  If you'll notice the dates on my posts, I've done nothing for many weeks.  Summer school is the reason.  It essentially removes five weeks from my life, but gives me part of the money required to do things like build airplanes.  The spousal unit (my beautiful and overworked wife, Karen) is leaving for five weeks to lead a hike through the Rocky mountains in Wyoming (grizzly bear country!), so I have no excuses.  I plan to work at least eight hours each day on the airplane.

My airplane got the bird!                                                          

I left the garage door open and unattended for approximately four hours yesterday, and the result is shown in the picture.  Birds are the hardest-working little buggers I've ever seen.  I never saw the

,

birds who did this, and I hated to move the nest, but unless I was willing to suspend work for about a month I had no choice.  At least they hadn't managed to lay eggs yet.  Another pair of birds, this time Carolina Wrens, were aggressively trying to build a nest in the rafters while I worked in the garage not 10 feet from them.  I tried flushing them out by waving a broom around without success.  Finally, I enlisted the help of my pet owls, who were more than willing to stand guard at the door, looking quite fierce and intimidating as they swayed to and fro in the breeze.  So far, so good.  No more birds in the garage.

On a happier note, the fuel lines are finished.  The bad part of this is that while installing the fuel lines I discovered that I had routed the brake lines through the wrong grommets in one of the bulkheads, requiring that the long lines that go from the master cylinders on the rudder pedals back to the landing gear had to be redone.  I remember double-checking this as I did it in order to avoid just such a fowl up.  I managed to do it anyway.  This, of course,

means I get to either do the boiling-water trick one more time or try something I read today on the forums that was supposedly proposed by none other than Ken Krueger: run a #29 bit through the first 1/2 inch of brake line, which allows the inserts to be pushed in with no heat.  This sounds too easy, makes too much sense, seems too obvious, and therefore probably won't work.

While I'm waiting on the new brake lines to arrive, I started on the side skins, the first step of which involves removing a thin strip of metal in order to form the slot through which the wing spar will pass.  The manual says this can be accomplished with tin snips.  My initial attempt says this won't work (at least with my skill set).  I wasted an hour looking for my nibbler, which is the obvious tool, and gave up for the night.  Ordered a new nibbler from Spruce.  Very frustrating.

(5-27-13) Update!

Using a #29 bit to ream the ParFlex makes pressing the insert into the tube a snap.  It's still an interference fit, so it's plenty tight.  It's irritating thinking about all the headaches with the boiling-water routine that I could have avoided.

(Page 28-03) Fabricating fuel lines..........                  

...is the easy part.  Installing them is a whole 'nother smoke.  Right off the bat I learned two important things:  The nut for the fitting will go around a 90-degree bend, the sleeve will not.  This, of course, means that the sleeve must be on the flare side of the bend as the bend is being made (false start number one). 

The picture shows the first completed part and three short pieces of tubing (now scrap) which resulted from my first three attempts to fabricate the part.  Actually making the bends is childishly easy using the tool (purchased from Spruce) shown at the top of the picture.  It was impossible, however, to make that first 90-degree bend (shown on the lower right of the pic) as close to the end as shown in the full-size picture in the plans.  That extra inch or so didn't matter when installing the part in the fuselage.  All of the parts such as this one which can be fabricated independent of the fuselage structure should be easy.  No so for the parts which require one end to be flared after passing through the grommets in the bulkheads.

The tube going from the fuel pump to the fuel valve requires that the aft end be flared and fitted with the sleeve and nut before being installed in the fuselage.  The un-flared forward end is then passed through three bulkheads with grommets (it's a tight fit) and ends up near the fuel valve to which it must attach.  The only way to accomplish 

this is to alternate between bending and straightening short sections of tubing while feeding it through the holes.  The short piece of tubing at the forward end had to then be cut to length (be sure to have a close-quarters tubing cutter -- the one shown in the first picture won't come close to fitting) and flared (see picture at right) in a very small space.  I could only do this by hand bending the tubing out about 45 degrees, installing the fitting, then hand bending it back into alignment with the fuel valve fitting.  I'll be holding my breath when I pressure test this.

Two small deviations from the plans could have made this process much easier.  The s-bend between the fuel pump and the aft-most bulkhead could be moved aft approximately six inches without affecting anything.  This would allow the whole tube to be slid forward that amount, giving much more room to install the forward fitting.  Also, riveting the fuel valve assembly could have been delayed, allowing the valve to be removed (it was clecoed in place).  It's a real learning process.

One last piece of advice:  When the plans call for cutting the tubing to a particular length, add at least an inch to the callout.  Trial fit the piece, mark the correct length, then cut.  For the tube which connects to the gascolator, I cut to Van's specification, did the bends, flared the ends and installed the fittings.  Ended up 1/2 inch short.  One more piece of scrap.

My crowded shop..........                                                 

With the arrival of the wing kit, the lack of space has become critical.  The fuselage is on its side on the table, awaiting installation of the fuel lines

(not looking forward to fabricating the lines with all the exacting bends).  The parts from the wing kit are distributed about the shop, with the wing skins on a platform suspended directly above the car.  The stabilator is standing on its end leaning against the tail cone (not visible in this pic) between the car and the fuselage.  The plan is to move the tail cone and the stabilator to the attached garage and build the wings on the saw horses between the car and the fuselage.  It seems that most people build the two wings at the same time, and maybe the plans call for this, but clearly I don't have space.  One option would be to evict the car, but I can't bring myself to do that.  It has spent very few nights outside since I picked it up at the factory in Bowling Green.  The Spousal Unit (my beautiful and long-suffering wife, Karen) offered to relinquish her spot in the attached garage, but I know better than to accept that offer. 

The other slot in the attached garage is occupied by my antique, which I'm going to continue working on any day now (as I've been saying for several years -- I frequently ponder the phrase "too many irons in the fire").


Brake lines continued...                    

The forward ends of the brake lines require installation of the insert, sleeve and nut (see March 10 post) in the shop rather than in my kitchen, a result of having to thread the lines through the bulkhead grommets, which can only be done before the ends are installed.  The boiling water required for press fitting the insert into the line was accomplished with the rig shown.  A large Kronenbourg beer can, which for unknown reasons I had saved for the last 20 years, was cut in half and pressed into service as a pot (it was explained to me that the kitchen pots were not appropriate for this purpose).  I still had difficulty getting the inserts to press in all the way, even after coating them with dry Boelube.  I can't be the only builder with this problem, although I haven't heard anyone else complain about it.

 

Redneck respirator........                                                           

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Being born and raised in South Carolina, my neck is inescapably a bit pink, so I don't always  go for the most sophisticated solution to the problem at hand (part of the reason I didn't buy a Porsche).  So to avoid inhaling paint fumes, rather than opting for the Hobby Air rig (~$600), I'm using a 40-foot length of corrugated PVC attached to the mouth piece from a snorkel.  Breath in through the mouth, out through the nose, don't get out of phase.  I used this method spraying two-part epoxy on a previous project and escaped unharmed (as far as I know -- my lungs may be Cub yellow inside).  I'm using a bit of nylon hosiery on the other end to keep critters out. 
                                                                                            For the interior, I'm using rattle cans exclusively for both priming (a combination of NAPA 7220 and Rust-Oleum self-etching primer) and for the top coat (enamel).  I want a lighter color for the dark places (foot wells), so I'm applying a clear enamel over the 7220).  I want a medium-to-dark gray for the visible parts of the upper portions (roll bar, side rails, etc.), but am still unable to find anything suitable that's not a primer rather than top coat.  Since I'm going with a full interior, a lot will be covered but there's still a lot of visible metal.  I'm assuming it's OK to leave some of the hidden-from-view interior parts in primer with no top coat.

 

Why I'm making no progress.......                            

Years of abuse of my rotator cuff (tennis, lots of other sports) culminated in tearing the muscle off the bone while sqeezing hundreds of solid rivets for the airplane build.  The surgical repair (four weeks ago) involved re-attaching the muscle to the bone with dozens of plastic anchors.

The really bad part is that I have to wear the sling for six weeks, with no load being applied for ten weeks. Kinda makes it difficult to get much done on the airplane.  Being right handed, I'm having to write on the blackboard lefty, reach across to shift gears with my left hand, brush my teeth left handed, etc.  Not fun. 

Of course, it's just my luck that Van's, on April 1st, announced the availability of a product which would have prevented the shoulder damage.  Van's AN470 Rivet Spray removes the need for squeezing, bucking or pulling rivets.  This product is simply sprayed onto the rivets after they've been placed in the holes, allowed to "set" for a period of time, then, as if by magic, they form the correct shop head and you're done. ;-)

(page 27-04) Brake line fittings.........                                     

Getting the brass inserts fully inserted into the brake lines is proving to be a bit of a problem.  As instructed, I put the fittings into a pan of boiling water, then tried to press the inserts in, with results as shown.  They're about 1/16th inch away from being flush on each fitting.  I tried repeatedly, same outcome.  I'll next try adding salt to the water in an attempt to raise the boiling temperature, but my calculations show I'll get a max temperature rise of about 2 degrees C, probably not enough to matter.  We'll see.   

                                                                                

Update (4-12-13)         

 

The fuselage kit comes with two 15-foot pieces of plastic brake line.  From these, two pieces a bit under eight feet must be cut, along with various other shorter lengths.  I cut several of the shorter lengths first, and ended up unable to make the two long pieces.  One long piece must be cut from each 15-foot length.

 

Van's supplies interchangeably two slightly different kinds of tube.  One has a yellowish hue and a different 10-digit number at the end of the designation.  They're both Parker Parflex with the same dimensions.  The one with an ending number of 006125903 was much easier to get the inserts into (see above).  When I reordered the line, I tried unsuccessfully to specify that one.  The lady at the desk showed only one part number.  I'm hoping for the best. 

(page 26-03) Seat backs and interior paint........                                             

I wish everything went as smoothly as this section.  The only distasteful part was match drilling the piano hinges, but even this was OK.  The piano hinges allow for some limited adjustment of the seat back angles.  The seating position in the -12 is much more upright than I would choose, the ideal being something similar to the La-Z-Boy I currently occupy.  Cars, airplanes, or chairs, I like to recline.

After hanging the pedals I realized I should have painted everything down there prior to the hanging (which I will under no circumstances undo).  I had primed most of it with NAPA 7220, but no top coat.  I'd like to use a medium gray for all the visible bits of aluminum in the interior, but have been unable to find this in a rattle can.  My current plan is to top coat the 7220 with clear enamel, which is what I did for the seat backs.

The orange stuff seen in the piano hinges at the top is .090-inch string from a string trimmer, placed there to prevent paint from getting into the hinges.  Oddly, it wouldn't fit into the other hinges even though the rod extracted from the hinges measures the same for all hinges (.088 inch).  I must investigate this.

(page 27-02) revisited                                                             

Using the new pedal alignment method worked much better for the match drilling, and I wish I'd used it for all four.  Reiterating, I clamped the torque tube to the rudder pedal as per the build manual, but rather than match drilling the #30 holes completely through on each side, followed by the #12 and 1/4 inch bits, I used the pilot holes in the rudder pedals to "mark" the torque tubes by lightly inserting the spinning #30 bit.  I marked the relative position of the torque tubes and the rudder pedals with a sharpie, then moved the whole thing to the drill press and match drilled all the holes.  It was easy to maintain the alignment by looking at the sharpie marks.  Worked great.

Assembling the nylon blocks around the tubes and bolting the whole assembly to the nutplates on the shelf was not easy but succumbed to a little of persistent effort.  I taped everything together with blue painter's tape, which held until I started the bolts with my fingers.  The brake cylinders were installed before mounting the whole rig to the shelf.

Skipping now to the seat backs before installing the brake lines.

(page 27-02) Rudder pedals and brakes...............            

Skipping from 23-04 to section 27 allows installation of the pedals and associated plumbing without having to reach around the side skins.  This situation has occurred several times where it seems advantageous to do things out of order with the build manual and it always leaves me wondering if I'm missing something which will later bite me.  The various steps for the trial fitting and assembly are easily understandable and fun with one notable exception: maintaining the proper orientation of the parts while match-drilling the steel tubes.  The picture shows the assembly in the proper orientation which it will assume when suspended from the firewall shelf.  It's put together and drilled upside down, with the assembly resting on the bolt heads through the nylon blocks.  In that orientation, the brake pedals are supposed to be clamped so that they are vertical.  Problem is, it's hard to keep them that way while match drilling (first #30, then #12, finally 1/4 inch) through the steel tubes.  The top of the pedal on the far right ended up a bit too far aft.  I'm attempting a fix by slotting the hole with a rat-tail file, then filling in the opposite edge of the hole with weld material, thereby moving the hole circumferentially.  After being spoiled by drilling so much aluminum, drilling steel is a challenge.

[Update:  After pondering the situation, I decided to abandon the fix described above.  I ordered a new pedal and torque tube from the Mothership and, rather than match-drilling in place as described in the build manual, will do the drilling in v-blocks on the drill press.  The plan is this:  Install the new parts on the assembly as before (positioned upside down from what's shown), using the pilot holes in the pedals, mark where the holes go in the torque tube, then take the two parts to the drill press and complete the drilling.]

(page 23-04) The bigger-hammer approach...                   

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...to aircraft construction actually works, it seems.  After all the pounding, twisting, bending and spreading in a vise, the longerons fit well.  I'm deliriously happy to be done with them.  There's still a fair amount of match drilling into them, but no more bending.

It finally occurred to me that I could store the tail cone (seen here resembling a skinny aluminum tepee) by standing it up, thereby taking up much less space.  I'll need the space for the wing build.

I've decided to skip ahead to sections 27 and 28 (brakes, rudder pedals, etc.) which should be considerably easier without the side skins installed.

(page 20-05 revisited) Landing gear service bulletin.........          

Since I've yet to acquire the finish kit, the parts I received to comply with the Main Landing Gear Service Bulletin consisted of a small additional bracket connecting the center channel to the newly beefed-up side skin (at least it'll be beefed up when I install it), skin doublers (and triplers), and some CherryMax rivets to replace the now-drilled-out LP4-3s and to install the doublers.  CherryMax rivets have approximately four times the shear strength of LP4s.

The complete kit for the service bulletin will include massively beefed-up bits which attach the landing gear to the center channel.  The end result will be a much stronger landing-gear structure, which should put an end to the wrinkled side skins which showed up on some -12s after hard landings (mostly on grass).

The yellow arrow in the picture shows the new bracket with CherryMax rivets installed.  Some builders report being able to set the stronger rivets with their existing pullers.  Not the case with me.  Neither the pneumatic nor the manual puller would work.  I therefore ordered the Cherry G27 puller (shown in the picture) which, of course, performed the task admirably.  I'm always looking for an excuse to buy a new tool.

(page 23-02) Long(eron) nightmare..............                        

All of the horror stories about bending the longerons turn out to be true.  It's the biggest PITA so far by a wide margin.  I bought Larry Buller's dies, which I think are well worth the money (somewhere in the neighborhood of $47), so I was feeling pretty confident.  Pounding the bejesus out of the aluminum as put forth in the build manual didn't strike me as a good procedure either for spreading the angle or making the lengthwise bend.

The first step, after making the initial length cut and making the various marks on the extrusion, is to spread the first foot or so of the angle to 95.4 degrees.  Most builders, it seems, are using one of the plastic angle finders sold on the aviation aisle a Lowe's.  I drew the angle on a sheet of paper, using a protractor which had, in a previous life, been used to find elevation angles for communications satellites (hence the lines drawn on it, and, yes, I'm that cheap.  I hung the protractor from a paper clip and sighted along the lines).  I then bent a small length of aluminum angle to match and used it as a template as I spread the longeron.

In order to accomplish the spreading without pounding the apex with a heavy hammer (as called out in the build manual), I decided to squeeze the angle against a large socket in a 5-inch vice.  This worked well using a 16-inch pipe as a cheater on the vice handle.  I tried using a longer piece of  3/4-inch pipe (the width of the vice jaws) as a spreader rather than the socket, but this required more force than I could muster, even with the cheater.  For the second longeron, I compromised using a longer, larger diameter deep socket as a spreader.  This was the best of the three.  After reading other blogs, I discovered that others used a version of this method.

After spreading the angle 5.4 degrees, the build manual calls for the top surface to be twisted back 2.7 degrees so that it's once again horizontal.  According to the manual, this is to be accomplished using a "metric crescent wrench."  After a long search and at great expense, I was able to acquire one of these from a mail-order outfit in Russia. ;-)  Since I'm finished twisting longerons, I'll part with it for half price.  Oregonian humor.

The bending of the longeron was accomplished using the aforementioned dies from Larry Buller (shown just to the right of the small vice in the picture).  These worked well for the bend, but I had incorrectly thought that using the dies would limit the out-of-plane bend which results from the pound-with-a-heavy-hammer method described in the manual.  This didn't happen.  I started out bending the amount required to fit the template, then rotating the angle 90 degrees in the vice and removing the unwanted bend by hand (the dies can only bend in one direction).  This reduced the original bend, so it was an iterative process: bend, rotate, bend, rotate, etc.  On the second longeron I wised up and made the bend in the desired direction a few degrees more than needed to fit the template, resulting in less unwanted out-of-plane bend to remove.  This whole process did not leave me with a warm, fuzzy feeling like some of the procedures do.

***Update*** (1-22-13)
If I had to do this again, I'd use the "Orndorff Method" where the two longerons are clamped together in a T and bent at the same time.  This prevents out-of-plane bending and apparently works well.  Search on it.