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Horizontal Stabilizer
Empennage construction begins with the horizontal stabilizer, which I think is rather odd. The vertical stabilizer is
nearly identical in skill required, principles, tools and methods, but since it is smaller, it's much easier to handle, and,
IMHO, would be a better place to start. At any rate, the instructions say HS first, so that's where I started.
  Begin
by relieving the edges and rounding the ends of the reinforcing bars so they will lay flat in the spar channels and have no
sharp edges to create stress risers. Cleco the bars in place and match drill to #30. Then cleco and drill the hinge
brackets. Be sure to mark them so that you put them back where they were match-drilled later. Take it all apart,
de-burr and prime as desired or required. The bars are not alclad, so must be primed. It's the builder's choice
whether to prime the alclad spar channels.
 With
the bars and hinge brackets drilled to proper size, it's almost time to set the first six of 17,000 or so rivets. With
the reinforcing bars clecoed in place, slip the center elevator hinge bearing between the brackets and bolt the brackets to the
spar assembly. Add a couple of clamps to hold the bearing flange still between the steel brackets and drill the six rivet
holes using the steel bracket as a guide. Take it all apart, prime the bearing flange, put it all back together and rivet the brackets to
the bearing. Take the bearing back off the spar so you can reach the last two rivets, then put it aside. You might
as well get used to this 'put it together, take it apart, do it again, and again, now rivet it, maybe,' routine.
 The forward spar
reinforcing angles get some reaming, filing, a bit of grinding to smooth, a few judicious smacks with a mallet to
achieve the required 6-degree bend, and finally a little more reaming.
  The
next step is to straighten all the ribs and cleco the right and left HS skeleton assemblies together and match-drill all the
rivet holes. Take the skeleton apart, de-burr the holes and clean up all the chips, chunks and shavings. Cleco the
skeleton back together then add the skin and drill all the skin-to-spar and -rib holes. Take it all apart, de-burr the holes (both
sides) and the edges, and clean it up. Dimple the skins and skeleton as required.
Option - in a effort to get a tighter fit between the skin and skeleton, some builders use Cleveland's Tank Dies to get a
slightly (0.007") deeper dimple in the understructure and standard -3 dies for the skins. I didn't bother (ok, I didn't think
about it until after I had already dimpled, and didn't feel like doing it over).
You should have already decided whether to prime it all or just the minimum - this is the wrong time to start a primer war with
yourself. Clean and prime the parts as required or desired.
  With
the reinforcing bars clecoed in place, tape over the holes that get attention later and rivet the bars to the spar channels,
then cleco and rivet the hinge brackets in their proper places - you did remember to mark the brackets when you took the whole
thing apart yesterday (last week?), didn't you? Bolt the center bearing assembly to the spar and torque the bolts.
  I
learned early on that a big vise makes a dandy bench mount for the pneumatic rivet squeezer. A foot control for the valve
would be a bonus, but they're expensive and (I believe) require fiddling with the valve mounted in the tool to change from one
to the other - not plug and
play.
Here's the spar channel with the reinforcing bars and mid-span hinge brackets all riveted in place. The two open holes will get
blind rivets to hold them to the center rib after the spar is riveted to the skins.
 Cleco the forward spar
channels to the reinforcing angles and rivet. Remember to use AN426 flush rivets in the center holes. Cleco and
rivet the inboard ribs to the spar (you labeled all this stuff too, right?).
 Cleco HS-707 to the
top of the skin and cleco HS-708 in place to help hold the skin tight against HS-707. Rivet HS-707 to the top of the
skin. Remove HS-708. Repeat for the other side.
  Cleco
the forward spar assembly and HS-708 ribs in place inside the left skin.
Rivet per the plans.
 Repeat on the right.
(wait a minute... what's all that other stuff in the pictures...) Busted.
RV-7 left wing spar in the foreground, completed RV-7 tail hanging on the wall. That's actually McNeely's RV-8 HS on the
bench.
  Cleco
the rear spar assembly in place. Rivet the rear spar, inboard and outboard ribs to the skin.
 Horizontal stab
complete.
Relax, have a homebrew.
(You don't drink that store-bought rot, do you?)
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