Fin Spars

Assemble the fin skins, ribs and spars on the fuselage using self tapping screws in the pre drilled jigging holes provided. Level the fuselage and get both the spars vertical. Make sure that the front spar is not at all twisted as this affects your measurements a lot!
Once absolutely sure that both spars are vertical drill 4 holes to attach the front spar to its bulkhead. The 4 holes will ultimately be used for the M5 / 3/16" "chicken bolts" which you'll use during bonding. Drill the rear spar for 4mm pop rivets to be used during bonding. Disassemble everything, roughen bond areas, apply cotton flox and re assemble just the spars. Install the "chicken bolts" to hold the front spar and the pop rivets to hold the rear spar. Once cured drill out the pop rivets. Remove the chicken bolts (or if a chicken like me - leave them in!). Roughen and apply layers of 280gsm around the spars, pulley mount area and tailspring clamp attach area as shown.