Semroc (Centuri) Taurus Build, Part 12, Where'd That Tube Go?

All the balsa is filled, all the tube seams are filled.
Everything is painted and pretty much ready for assembly and decals. Well, almost . . .

I can't find the center ST-8 tube!
It was filled and painted white, ready for the tunnels and decals.
We've all misplaced launch lugs, but I've never lost a tube. I thought about putting in an order for a replacement, but you know what will happen. A day after the order is made, I'll find the original.

Another problem - I don't know what the tube length was. The kit height is 23.5" tall. I can measure the assemblies, subtract that total from 23.5" and I'll have the ST-8 tube length.

The Semroc instructions say the tube is a ST-857. Using Centuri lingo, that might mean it's a ST-8 tube, 5 3/4" long.

The Semroc Classic Kit parts list (CLICK HERE) says the length is 5.75" long.  Under the "Original Part No." listing it says: ST-8?

Then I went to a new Centuri list being compiled by Jay Goemmer. To see the Centuri kit parts list: CLICK HERE
This list also gave me a length of 5.75" long.


To get the model to 23.5" tall, on my model that ST-8 tube ended up at 6" long. Some Semroc reissued kits aren't always exact clones.
I was lucky enough to find an 8" length of ST-8 tubing. My OOP Odd'l Rockets Pipeline kit used ST-8 tubing, a lucky break. Keep your extra rocket parts - You never know!
The new piece of tubing was cut to size, seam filled, filler/primered and shot with gloss white.

The way it always goes - That original tube will show up in a day or so - 

Semroc (Centuri) Taurus Build, Part 11, Masking The Lower Fins

The lower half of the fins are masked to leave them white.
Enlarge the picture to see the two layers of tape - the knife blade is sitting on the brown masking tape, the Scotch tape is below that.

This is after the flat black was sprayed and the tape is ready to be lifted.

I did have a little bit of bleed under the tape.
The top picture is the before,


This is after a little "push up" against the black paint to clean up the line. I don't scrape the paint off, it is pushed back while it is still a bit sticky.

Here's the finished low end mask.

Notice there is a thin strip of brown tape keeping the paint off the gluing edge of the pylon standoff.

Semroc (Centuri) Taurus Build, Part 10, Paint Problems & A Fix

I don't know what happened here -

One adapter came out fine after the first white undercoat, the other adapter still showed rough balsa under the paint!
I had to go back and hit it again with filler/primer, sanding and then more gloss white.

This picture shows some sanding of the fillet areas, a normal rough spot. The paint has been sanded down and the gray primer is seen.

Note there is a thin strip of masking tape down the pod support gluing outside (pod root) edge.

More rough edges were found on the leading and trailing edges of the pod supports. Filler/primer was sprayed into a cup. A Q-tip dipped in and the paint rolled just over the leading edges.  

Dry, sand and spray with more gloss white after 48 hours.

Handling Flat Finishes?

From the Facebook Model Rocketry Fanatics page, Matt Steele posted this:

"Chas Russel brings up the Pod Bay Door's "Uprated Saturn 1B" for its first flight."

TIPS: This shows why I rarely paint sport models with a white flat finish - Sweat, skin oils and dirt stick to flat (matte) paint. Notice the gloves worn to keep the finish clean and white.

Semroc (Centuri) Taurus Build, Part 9, Engine Mount & Balsa Pod Mounts

I was concerned about the old-school black coupler between the engine mount centering rings. There is a lot of surface area on the sides to get stuck while gluing.
On the left you can see the white showing through on the lower centering ring after sanding for a sliding fit.
On the right is the position of the engine mount with the rear ring being recessed by 1/16".

The trick is to use enough glue so it slides in, but not too much glue that you get a shrink line (Coke Bottle effect). You sometimes see these on the outside of the tube at the coupler top location.

The mount went in without incident - Whew!
The lower ring is recessed 1/16" allowing a rear fillet around the inside tube joint.

The tube was marked for three fins and the three pod mounts.

On the left, the tube has been scraped for gluing the root edges of the fins. One line is wider for gluing on the launch lug.

On the right the pod mounts are glued on. With six fins total I thought it might be easier to glue and fillet these first.

TIP: The longer the rocket, the harder it will be to get an even spray paint coverage. On tall rockets (when you can) spray the model in segments. Picture trying to paint an assembled Estes Mean Machine.
Mask off the exposed adapter shoulders to keep off the paint.

New (Good?) Spray Paint

I hate to recommend anything - especially spray paint.
So, I'm early for a dentist appointment and stopped at the nearby Ace Hardware store. There was some spray paint on sale. I'd been looking for some light gray paint. I picked up the Ace brand and some Ace gloss white.

Rustoleum 2X is handy, you can find it at Home Depot stores. But the Rusto gloss white can spray in chunks. The Rusto gloss black and red can spatter giving you a textured or orange peel finish. That and the nozzles often clog!

So far . . . 
My experience with the Ace brand Premium Paint and Primer has been very good! There are other Ace named products so look for this can.
Even though this can says "Paint and Primer" it's not a true "primer", it's paint.
Rusto 2X can take a while to dry, it can stay sticky for a few days. The Ace paint dries to the touch in 30 minutes in Florida humidity! I'd still wait another day before applying decals on the Ace paint.
EDIT: Plastic nose cones will still take longer to dry. Plastic doesn't "breathe" like balsa and Kraft body tubes.

Here's some notes:
The Ace GLOSS WHITE doesn't dry quite as shiny as the Rusto 2X.
The Ace LIGHT GRAY dries smooth and glossy.
The Ace GLOSS YELLOW dries smooth, not as shiny as the Rusto 2X
The Ace GLOSS BLACK dries very shiny and smooth. Much better finish than the Rusto 2X

The spray nozzle on the ACE Spray Paint is like the Duplicolor nozzle. You can rotate the white tip for different wide or narrow coverage. I tried the narrow path spray and went right back to the wider coverage.

I know - everybody has a paint preference. But - until I see some negative results using the Ace brand paint, I'm going to buy other colors! Rustoleum 2X seems to have changed their formulations a few times in the past ten years. You cross your fingers and press the nozzle button.

FAI World Cup Competition Video

On the NAR Facebook page, 
Steve Kristal posted a link to the recent F.A.I. World Cup competition in Ukraine.

This is one of the best produced rocketry videos I've seen. Great slow-motion launches and some closeups of the international scale builds.
To view it: CLICK HERE