(page 12-02) Fitting fairings............           

Had I trimmed the v-stab and rudder fairings to the indentations from the molds, it would have been essentially perfect.  Not knowing this beforehand, of course, I used the fit-remove-trim-repeat method as given in the plans and ended up there after a couple of hours and lots of fiberglass dust.

Sticking with my plan to paint parts before assembly, I'm looking into the Stewart paint system, which is supposedly less toxic.  I'd like to never use Alodine again, if possible.  In the interest of time I considered having the painting done by someone else, but after hearing horror stories about wings being dropped by painters, I'm pretty much resigned to doing it myself.  This, of course, will require purchasing an HVLP spray system and accessories.  $$$.

Notice the cord attached to the top of the v-stab tethering it to the rafters. It would be a disaster if this thing fell over, denting the skin.  I have nightmares about the tail cone falling off the saw horses.

(page 12-02) My 433rd favorite thing..............              

....sanding fiberglass.  I postponed pages 11-01 through 11-05 and 11-08 through 12-01 for a number of reasons.  I've definitely decided on the paint-as-I-go approach, thereby eliminating some of the dissassembly-reassembly called for in the plans.  This brought me to the v-stab and rudder fairings, which require sanding to allign with and fit inside the metal parts.  The plans suggest wrapping some 80-grit around "a cylindrical object" and doing it by hand.  This would have taken a while, and we're currently experiencing the mother of all heat waves -- 101 F this particular day -- so I carted the belt sander outside (to keep fiberglass dust off everything in the garage) and used it.  I considered using a Dremel tool with a sanding drum, but thought it would be difficult keeping the straight edges straight with this.  Worked like a charm.  I used the curved top of the sander for the curved rear portion of the v-stab fairing and the flat part for everything else.  The edges being sanded will be hidden beneath the aluminum, so it's not critical anyway.  The whole operation took only ten or so minutes.

Ron Alexander has a good writeup on painting airplanes (Google his name and the topic, it may have first appeared in Sport Aviation).  He strongly suggests painting individual parts before assembling the airplane, if possible.  I'm curious why most builders don't do this (maybe I'm about to find out).  I'm aware of the possible variations in color with different batches of paint.  I'll take the chance.

(page 11-06) School's out.....                                                                    

All final exams are graded and all grades are turned in.  The laws of thermodynamics will not pass through my brain again until August 20, replaced by visions of making massive progress on the RV-12.  I also have until the end of the month to get my antique Corvette inspected or my registration will be revoked.  Busy month ahead, made easier by the fact that the Spousal Unit (my beautiful and brainy wife, Karen) accepted an offer today for a full-time faculty position in Mechanical Engineering here at UNC Charlotte.  What are the odds that a husband and wife would be able to teach in the same department?

The servo tray was near disaster.  The plans say to rivet the doublers, then final drill .25 the holes.  This would have worked fine if I had clamped the un-riveted ends together before drilling.  As it was, the doublers, being held to the tray by rivets on the ends, bent significantly when drilled, embedding chips between the doublers and the tray.  The rivets for one doubler had to be drilled out and the doubler removed and pounded flat with a hammer.  I was not happy.

I'm struggling with the decision to paint each part as I build it or wait, as others seem to do, until after flight test to paint the whole airplane fully assembled.  I would really like to avoid installing and removing the horizontal stab and vertical stab (and anti-servo tab and rudder) multiple times.

(page 10-11) Tail cone finished.........
                                              

The side skins and upper side skins fit well with the initial edge brake (break, in Oregonian) of about 2 degrees.  No gap in the seams of the lap joints.  The top skin was another animal entirely.  Near the aft end of the fuselage, a much greater brake angle was needed.  Happily, the device I showed a few posts back worked like a charm once again.  This tool is worth every penny.  I advised leaving the blue plastic on while braking the edges to prevent scratching.  I had removed the plastic, however, before final clecoing.  Clear packing tape was applied to the edges before using the tool (repeatedly, in order to get the desired angle).  This worked quite well.  No scrathes on the alclad.

 

Speaking of scratching the alclad, I think builders worry way too much about this.  All that pristine aluminum is going to get scuffed with ScotchBrite before priming, so why worry?  Deep scratches should be avoided, of course, but I don't sweat the small stuff.

On an unrelated topic, I think way too much metal is removed in the name of deburring.  A chamfer should not be put on the holes.  At most, burrs protruding above the surface should be removed.  Quoting from page 87 of the sixth edition of Standard Aircraft Handbook, which ships with every Van's kit, "Burrs under either head of a rivet do not, in general, result in unacceptable riveting.  The burrs do not have to be removed......<snip>......care must be taken to limit the amount of metal removed when deburring.  Removel of any appreciable amount of metal from the edge of the rivet hole will result in a riveted joint of lower strength."  The punched holes in the aluminum really don't have to be deburred at all.  For the sheared edges of the sheets, the sharp edge should be deburred.  These, like all the opinions expressed here, are my own.  Other builders should make their own decisions.

(page 10-10) A cluster..........                     

...of clecos.  The side skins (left and right and upper left and right) would have exhausted my supply of clecos had I done all four skins at once as called for in the manual.  Except for curved surfaces, I usually cleco every other hole, rivet all the holes left open, then remove the clecos and rivet the rest.  Clearly I didn't follow this procedure for the stabilator bearing plates (the dense cluster shown in the photo), the reason being that a gap of from 1/8th to 1/4 inch existed between the plates and the skins.  Once again, I thought something from Van's was less than perfect.  Wrong again.  Putting all the clecos in closed the gaps and everything looks great.  The side not shown is completely riveted, and I hope to finish this side today.  The Spousal Unit (my beautiful and exhausted wife, Karen, who is working all waking hours preparing to defend her PhD dissertation in August) has said she wants me out of the house until this evening.  Wilco, my dear.

(page 10-09) Static system...                                           

Took a while to decipher this.  The pages sent inside the ziplok with the static stuff refer to an RV-9, so the diagram didn't match the build manual.  Also, the HomebuiltHELP videos (the biggest bargin in homebuilding) show locations for the various bits which don't match the description in the manual.  Both showed the plastic tee on the side rather than top center as the manual specifies.  The manual calls for heating the 1/8th-inch tubing prior to slipping over the fitting, but this wasn't required.  For the transition to the 1/4-inch tubing it was quite necessary.  The procedure calls for slipping a short piece of 1/8th-inch tube over the plastic fitting, then slipping the 1/4-inch tube over that.  I slipped the 1/8th-inch tube on (no heat), heated a cup of water to almost-boiling in the microwave, stuck the 1/4-inch tube in the water for about 30 seconds, then slid it on.  Worked perfectly.  Very tight.  I'm wondering now if heating the 1/8th-inch tubing, though not required for the slip fit, would have somehow helped the bond with the plastic.  If I had it to do over, I'd do this.

The other 1/4-inch tube shown is for the ADAHRS.  Not sure how this fits into the grand scheme.  The zip ties are not pulled tight yet.

(page 10-08) Static port questions...                  

....answered (I hope).  After reading the instructions for installation of the static ports, I was skeptical.  Several people on the forum had trouble driving the mandrel out of the rivet once it was pulled.  Others had problems securing the 1/8th inch tube to the shop head of the pulled rivet.

I pulled the rivet, and, sure enough, the mandrel wouldn't budge.  I feared that tapping the drift too vigorously would damage the skin.  I used a Dremel tool with a cut-off wheel to remove about 1/64th of an inch from the shop head of the rivet.  The mandrel pushed out with no tapping.  If I had to do it again, I'd used a sanding drum rather than a cut-off wheel to remove the end of the rivet.

The next concern was that the shop head of the rivet over which the 1/8th inch tube must be pushed was quite short, even before removing a bit of it to facilitate mandrel removal.  It seemed that it would be quite easy to persuade the tubing to separate from the rivet.  The instructions say to "seal the joint with RTV", so, after cleaning the aluminum with acetone, I applied a substantial amount of RTV.  After hardening, it seems secure.  Reading the forum, I learned that "regular" RTV is corrosive to aluminum and that "sensor safe" RTV must be used.  Most auto parts stores have this.