Hangar 9 Alpha Trainer Assembly Manual page 17

Section 6: Installing the Horizontal and
Step 10
Locate the vertical fin and rudder assembly. Remove the rudder
and test fit the vertical fin in place. Make sure the rear of the fin
sits flat on the forward portion of the stabilizer. Once satisfied, use
a felt-tipped pen to mark the fin where it inserts into the fuselage.
Also mark the top of the stabilizer where the fin contacts.
Step 11
Remove the fin and use a sharp hobby knife to remove the covering
where the fin inserts into the fuselage, cutting 1/16" inside the
lines you drew in the previous step. Also cut away the covering
on top of the horizontal stabilizer, 1/16" inside the lines. Use only
enough pressure to cut the covering not the wood underneath.
Re-install the fin into the fuselage to check the fit.
Vertical Stabilizer
Step 12
Mix at least 1/2 ounce of 30-minute epoxy and coat the vertical
fin where it meets the fuselage and stabilizer. Also coat the fin slot
in the fuselage.
Step 13
Insert the fin into the fuselage and wipe away any excess epoxy
using rubbing alcohol and a paper towel. Make sure the fin is
90 degrees to the stabilizer as shown.
Step 14
Use masking tape to hold the fin in place as the epoxy cures.
Allow the epoxy to cure before hinging the rudder.
Continued
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