Section 6 - Vertical Stabilizer (finished! ... well, almost)

Over the last couple of days, I plowed through riveting the doublers and hinges to the spars, the ribs to the front spar, the skin to the assembly, and the rear spar to the final assembly.  I had to drill out a few bad rivets, but otherwise, it was fairly straightforward.  BUT, there is ONE darn rivet that even my thin tungsten bucking bar, on its side, can't buck (FYI, it's the forward-most rivet where the skin attaches to the top spar). I guess I'll be putting in an order for a thin yoke with Cleaveland Aircraft Tool!

Aside from that one rivet, the rest of Section 6 is complete.  In total, it took 31.1 hrs to complete a whopping 5 pages ... and that doesn't count most of the reading, planning, and cogitation!  This must be a slow-poke record.  Well, I'm taking my time.  Here are a few pics as I riveted everything together:

The pneumatic squeezer, with adjustable set to rivet, made quick work of the AN470AD4-sized rivets ... now, I just wish it was that easy to use the squeezer on the skin-to-spar AN426 rivets!

Section 6 - Vertical Stabilizer (priming)

I'm now at the stage of cleaning/prepping and PRIMING the metal - a topic that has been the subject of many highly opinionated forum posts.  It seems there are as many ways to prep and prime as there are people who have completed RVs.  From reading WAY too many of those posts, I'll summarize what I feel to be the best balance of quality, durability, weight, cost, ease and efficiency.

After all metalwork has been accomplished, including dimpling and countersinking (but, of course, BEFORE riveting anything), I cleaned the surface of all pieces to be primed with 100% acetone, using blue nitrile gloves to prevent oils from my skin to contact the surface and prevent the primer from sticking.  I decided to prime the following: all 4 ribs, both spars, the two doublers, and the internal rivet lines in the skin (not the outside, and NOT the entire internal surface skin - it already has a nice protection from the pure-aluminum alclad coating). I am NOT priming the 6 steel hinge brackets, since they came from Van's powdercoated (but, after match- and final-drilling, I did add a little 3-in-1 protective oil to any exposed steel surface, to prevent rust).

After acetone cleaning the surface, I used a Scotchbrite maroon pad to scuff any surface to be primed - for the ribs, spars, and doublers, I scuffed every surface. For the skins, I scuffed only the internal rivet lines. I then cleaned the surfaces well with Kleenstrip Prep-ALL, let dry, and primed with SEM #39683 self-etching gray primer (aerosol can) - it is expensive (about $21 per 15.5oz. can), but it is easy to apply (no HVLP gun needed!), dries quickly, and is tough after it has cured.  I bought a little spray can trigger handle to ease application of the primer, and primed until I couldn't see metal (~3 light passes or so), waited 5 minutes, flipped the pieces and primed the other side (the skin was primed standing vertically). I plan on letting the primer cure at least 2 days before riveting.  Here are most of the pieces, drying/curing after priming the second side:

Section 6 - Vertical Stabilizer (initial assembly; mock-up; deburring)

As most of your know, sections 1-5 in the plans are background reading - some of this is covered if you take an EAA SportAir workshop, but I highly recommend reading every word.  Twice.

So, the Vertical Stabilizer (VS) is the first "real" part of the RV-14A that I'll be tackling, and having skimmed the plans, it looks like it should be one of the more straightforward sections.  Good thing Van's starts out with the VS - some of the other sections would be far too daunting (kudos to the early builders, who had to start with the wing kit first, since the empennage kit wasn't available back then).

Building an aircraft, even one as supposedly straightforward as a Van's RV-14A, is a lesson in humility. Although I read ahead in the plans, I did not realize that my initial tool purchase should have also included the following, which I bought recently:   small-diameter female dimple dies (I now have both the 3/32" and 1/8" sizes, just in case) ... I need those soon to dimple the ribs in the vertical stabilizer, since the clearances are less than the standard dimple dies. After a nice exchange with Annette at Cleaveland Aircraft Tools, I purchased a slew of other tools she recommended:  a special bucking bar (long; used for the empennage somewhere ... works on RV-14s and RV-10s), a trailing edge drill jig, a special #40 countersink,  an angled male dimple die (used on one of the trailing edges), a 12" back rivet set with a back riveting bucking bar (beefy!), a substructure dimple die set (dimples the spars/ribs/etc. a little deeper, so the skins mate better), a tank dimple die set (dimples a little deeper, to permit the Proseal to seep into the rivet pocket), and a few other tools that I'll discuss in later posts.  Again, I can't speak highly enough about Annette at Cleaveland Aircraft Tool - a level of customer service I'd imagine folks had in the '50s and '60s, but that I've never experienced before.

At the pace I'm going, a 5 year build sounds about right - the first day, it took me 2.5 hours to go through only the first page of Section 6.  I'm (finally?) on page 3 now, and can start to see the semblance of a real aircraft part.  I clecoed the 4 rib sections to the front and rear spars, clecoed the skin to that aggregate spar assembly, final- and match-drilled all the holes, and voila!  Progress: