This evening I installed the rail button anchors (2nd pic in post
#15), MMT and fins. But, before I describe that process, a pic...
An ugly but functional fillet of Fwd CR.
Dry fitting the aft end yesterday helped me plan the "Order of assembly".
01) Sanded all the fin roots, entire outer surface of MMT and the inside back end of the airframe with 220 grit sandpaper. Then wiped everything down with isopropyl alcohol.
02) Placed MMT and fins back into the airframe. Then using a mechanical pencil placed hash marks on the MMT where the fins roots rested. I also marked where the MMT protruded passed the fwd CR. Then I pulled the MMT out, and using a fine point Sharpie drew out guide lines for the root of each fin. Then using the mark for the CR, drew a line around the circumference of the MMT.
03) Drilled holes in airframe for rail buttons and glued the anchors in place with BSI 15 epoxy.
04) Mixed up some Aeropoxy with a nice dose of colloidal silica.
05) Applied a fillet of epoxy to the back side of the fwd CR/airframe joint. Also applied lines of epoxy where the front end of each fin will butt up against the fwd CR.
06) Applied epoxy over the guide lines on the MMT for the fins and CR.
07) Next I slid the fins loosely in place in the airframe, then I applied epoxy to the root of each fin. With that accomplished, I installed the MMT alligning the lines of epoxy with the roots of the fins, and then carefully nudged each fin into place against the MMT.
08) After triple checking that the fins and MMT were all properly positioned, I snugged up the 3D printed fin guides against the leading and trailing edges of the fins to help maintain fin alignment.
09) After I was satisfied everything was lined up, I checked all my glue joints.
10) Last but not least, I temporarily installed the aft CR and added some rubber bands around the leading edges and tips of the fins.
I am sorry I did not take more pics. I did not want to risk the epoxy setting up before I had all the parts in place and properly aligned.
That's all for today.