Semroc SPEV Build Part 9, Interior Engine Mount Masking

You've seen it at club launches - 
Many builders spray paint the entire model. Engine hooks, engine mounts and launch lug interiors get a coat of paint.
I like to keep the back end clean. Sometimes the bare surfaces will get a rubbing of white glue to seal everything up.
The rear mask on the SPEV is a little different. "Strakes" extend past the rear of the body tube. the inside of the extensions should be painted.



Small pieces of masking tape are set right below the exposed ends of the strakes.

These short pieces of tape were pressed down on my pant leg and pulled up to remove some of the stickiness.

More small pieces of tape were added below the fins covering all the inside of the body tube.
It's easier to apply the masking tape pieces with tweezers.






One small piece of tape was slid underneath the engine hook.
Spray paint could "glue" the hook to the engine mount tube.

More tape was wrapped around the rest of the engine mount tube.

An engine casing stuck on a dowel painting rod was inserted into the engine mount tube.

Rolled paper towel pieces filled in the wide gaps.
It's now ready for the white coats.

Semroc SPEV Build Part 8, Cleanly Gluing a Launch Lug TIP

Most builders simply run a line of glue down the lug and stick it on the model. Here's a cleaner method.

Run a straight line of glue down the lug.

To remove excess glue and straighten the glue line:
Pinch your thumb and index fingertips together and run the "V" (formed by the fingertips) down the glue line.
This leaves a thinner and straight line of glue on the lug.

Another tip for a straight lug:
When possible, use your aluminum angle to check the straightness of the lug.
If adjustments are needed check to be sure the lug is still on the pencil line after the angle is removed.

You'll still have to add fillets, there will be bubbles after the glue dries.
Use the Titebond Molding and Trim Glue for fillets, especially for the deep launch lug fillets.

Cancun Update 5 - Warning! No rocketry content here -

This morning there's a notice slipped under the door:
Comision de Agua Portable - Cancelacion del Servicio

I don't speak Spanish. Well, a little anyway.
After two years of Spanish in High School, I can still count to ten and swear in Espanol. I did some swearing this morning.

The water is shut off! With no warning, it was shut off before the notice was left. I guess that's how they do it here.

So there is 1. No showers, 2. No flushing the toilets, 3. No washing the dishes.
Everyday down here presents a new hurdle. It's almost laughable.
Whoever thinks show business is glamorous - is not in show business.

Semroc SPEV Build Part 7, Engine Mount Fit

Before burnishing the paper in the tube, be sure it is squarely set!
The overhanging edge should be somewhat parallel to the body tube edge.

From the center of the shim to the edges -
Press and roll a dowel pushing the paper shim into the inside of the tube.

After the paper is in place, you can apply some CA around the bottom edge with a Q-tip applicator.

This CA coating is on the lower 1/4", not farther inside.
The CA would seal the paper and not give a good bond when the mount is glued in place.

The mount is then glued in place.
The was better, a good sliding friction fit.

On the SPEV, the end of the motor mount tube is even with the end of the mainframe tube. The engine hook extends about 1/4" beyond the end.

Semroc SPEV Build Part 6, Engine Mount Fit

Here's a tip I picked up on the Sirius Interrogator build:
Set and tie the Kevlar length before gluing in the engine mount.
Lay the mount next to the body tube, allowing for the engine mount tube being flush or extending a bit out the back.
Fold over the Kevlar below the top edge of the body tube.
Tie the loop for the elastic shock cord attachment.

Unfortunately, the centering rings were small! the entire mount just slid right through the tube. I wanted a tighter fit.
I'll have to build up the inside diameter of the main air frame tube.
This method is best suited for LPR rockets.

A single piece of 24 lb. copy paper should do the trick.

Roll and set in the tube and mark the overlap.
Cut to size.

This is where a glue stick comes in handy.
Glue sticks allow for re-positioning. You'll probably have to try this twice to get it right.
Try for a good even coverage over the entire piece of paper.

Roll the piece and set in the tube. Allow the edge to overhang the end of the tube by about 1/8".

The ends of the roll will probably stick to each other.
In the next post the paper will be rolled into place from the center (bottom right corner) to the edges.

Semroc SPEV Build Part 5, Shoulder Build TIP

Sometimes the balsa on the edge of a nose cone shoulder or adapter can be chipped or rough.
Here's one way to get a sharper line at the lip of the balsa adapters.

Set the adapter into the adjoining tube. Leave a small gap
Brush on CWF almost over the raised lip.
You don't want the filler on the shoulder, just over and a bit around the edge that butts up against the body tube.

While the CWF filler is still wet - 
Press and turn the body tube against the shoulder lip.
This forces the CWF filler into and over the rough edge.

Pull the body tube out an you can see the new raised lip of CWF.

Sand down the lip after the filler has dried.

Cancun Update 4 - Warning! No rocketry content here -

Finally something I recognize!
Seeing the "La Casa del Whopper" was funny.

Here's my most recent Mexico chaos - 
I checked last night's online show schedule and my name wasn't listed.
I've worked the past two Sundays and found it unusual.

The agency was emailed but I didn't get an answer. Pick up was normally at 7:30 p.m.
To play it safe I waited downstairs for the driver. There was a knock at the door.

It wasn't a regular driver but a young lady named Carmen.
In broken English she asked if I was "Chris?". I answered "Yes" and we drove the 30 minutes to the resort.
Just as we were figuring out the pick-up time for the drive back, we were approached by one of the entertainment staff.
"What are you doing here? All entertainment is cancelled tonight!"
I didn't know it was Mexican Independence Day.

A meal is part of my contract. I didn't eat last night.
I should have stopped by the La Casa del Whopper.