Estes Mars Longship Build #7296, Part 3, Parts Prep 2

The large nozzle has the ends cut off.
To be safe, I mark the cut lines with pencil.

I use a fine tooth razor saw, then smooth the rough ends with a sanding block.

The large ring has an outside seam that should be filled.
The inside of the ring is visible on the finished model so I also filled the interior seam.

The inside ring seam fill was sanded with some 400 grit wrapped around an engine casing.

A rolled "burr" remained on the inside edge from when the ring was cut. The burr was also sanded down, even with the inside tube wall.

Estes Curvilinear #3231, Build, Parts 12, Ring and Engine Mount Gluing

The rear ring is pretty tight, held in place by friction alone.
I did apply a drop of medium CA at the rear of each joint to lock it in place. The nose of the model was held down so the CA glue ran into the fin/ring joint.
Be sure the fins are lined up on both sides of the slot before applying glue.

Here I'm marking a glue applying dowel to place a ring of glue inside the body tube.
The rear of the engine mount tube and main air frame tube are both even when glued in place. The dowel is set beside the mount and a pencil line marked with the top of the dowel just below the upper ring.
On the right is the ring of glue around the top of the dowel.

Set the dowel in the tube up to the pencil mark. Roll the glue bead in the tube. Re-apply until you have a glue line all the way around inside the tube.

Slide the mount in place and twist until the engine hook is in line with the launch lug. Fillet the bottom ring and inside body tube joint.