Engine Block Gluing TIP

Here's how we used to do it - Gluing the engine block in the old Wac Corporal kit.
I like how the instructions tell you: "Put a large dab of glue near the end of your little finger (or use a brush.)" It better be your little finger, I doubt other fingers would fit into a minimum diameter BT-20 body tube.
The problem is - glue is smeared all through the tube leading up to the desired final engine block position. After a launch, a hot engine could melt that leftover glue, gluing the engine in place!

The old Wac Corporal kit was a single, minimum diameter tube model. You would have to carefully (and quickly) position and glue the engine block in from the back end.

Take a look at the new Sasha instructions at the right.
You are still directed to glue in the engine block from the rear smearing glue around the interior. How you gonna' get that glue bottle way up thar?

TIP: This is a shorter engine tube, why not glue it in from the top?

1. Mark the yellow spacer tube at 1/4" (or whatever the kit calls for)
2. Slide the yellow spacer tube in from the rear and tape to hold it in place at the 1/4" pencil line.
3. Slide the engine block (dry no glue yet) in from the top end of the tube and on to  the top of the spacer tube.
4. Apply the glue fillet from the top - DONE!

Using this method there is no extra glue inside the tube and next to a hot engine. The tube interior is clean. Between that upper engine block glue fillet and the engine hook, the engine will stay in place during boost and ejection.

Estes Sasha Build #7271, Part 8, Booster Fin Fillets

The coupler is glued in, pressed in until it butts up against the upper centering ring.

TIP: Instead of rolling the fillets over the top of the rounded fin edge - do the leading edge first. This will keep glue blobs off the top of the fins.
Apply glue around the top, smooth and remove the excess. Then apply glue fillets down the sides of the fins.

Here's the booster fin fillets.
I'll do one fillet using Titebond wood glue. After that dries a second fillet is applied using the Titebond Molding and Trim Glue. The second M&TG rounds out the joint better than a another layer of regular wood glue.





Here's the back view showing the vent holes.
Notice the vent holes are centered between the fins.

Tangled Shroud Lines?

At the last club launch, one parachute got fouled up!

Using the method suggested by Ed Mitton -
I opened the snap swivel, removed the lines, untangled and replaced the loops side by side. DONE!

To see the original blog post: CLICK HERE

Estes Sasha Build #7271, Part 7, Booster Fin Fit & Glue

This doesn't normally happen doing my regular two-step balsa filling practice.
After the filler/primer dried there were a few balsa grain pores left. I rubbed some CWF into the pores and sanded it to surface at the same time I took down the filler/primer.





The fin tab fit was a little long. There is a gap at the root edge.

In the picture I've marked the area with a pencil that will be sanded down. Sand a little, check the fit then sand a little more.







On the booster body tube the filler/primer has been scraped down to the rough tube for a better glue bond.
NOTE: The primer has been scraped where the glue fillet be down the root edge joint.

The booster fin fit is much better. This is a dry fit before gluing the fin tabs to the interior motor mount tube.

Estes Sasha Build #7271, Part 6, Booster Engine Mount Gluing

Test the fit of the nozzle and coupler in the body tubes.

TIP: I usually sand an angle on the lip for easier insertion. With this small taper the inside of the body tube won't turn under.

The shoulder of the nozzle sets the depth of the lower centering ring.
In the picture on the right the tube is upside down, the fin slots should be at the bottom!

Slide in the engine mount and press in place against the nozzle shoulder. No glue now, this is a dry fit. From the top, mark the inside of the tube where the centering ring touches the body tube.

Use the marking guide, center the engine hook line between two fins.

Mark a dowel using the pencil mark on the inside of the tube.
Apply a line of glue around the dowel end an apply a bead of glue around the pencil line inside.

Slide the engine mount in, press the nozzle in the rear until the shoulder lip butts up against the tube end.

Turn the mount so the engine hook is centered between two fins

Sweaty Rocket Handling?

At a club launch I've been asked why I carry rockets with a paper towel around them. It's hot, and your hands are sweaty!
On a model like the Dr. Zooch Saturn V there are printed paper wraps. These wraps or a flat paint finish could be stained when handling on a hot day.

Estes Sasha Build #7271, Part 5, Tube and Balsa Prep

If you are new to the blog - 
I fill the tube seams and balsa grain before gluing the model together.
It is difficult to fill things if the model is assembled. In the end it makes for a cleaner looking model.

The picture shows CWF in the body tube seams before sanding to surface. Duplicolor Filler/Primer is sprayed and sanded. Filling should be complete.

Even launch lug seams can be filled.
I stick the lugs over the ends of a Q-tip for a painting handle. Brush on CWF, let dry and sand smooth.





The small antenna dowels are glued into slots on the forward edges of the fins.

After the CWF was brushed on, the slots were evened up using the edge of a Great Planes Easy Sander, the best sanding block out there.





The tunnels are formed from laser cut balsa strips.
Round over the sides using a block to keep the long shape consistent. Round off the top and bottoms.








Lots of balsa to be filled on this one!
All the pieces are taped to a scrap piece of cardboard and sprayed with filler/primer.