Estes LTV Scout, Build, Part 7, Great Tubes!

Oh, how I miss the older, tighter better made tubes!

They feel denser and stronger. 

The picture shows the BT-60 tube lower tube. The seams are very tight and were easily filled with CWF,   

The upper tubes didn't need any CWF, I couldn't find the seam recess! Just a good shot of filler/primer and sanding should take care of anything remaining,

Here the shorter tubes are slid onto rolled cardstock handles for a filler/primer spray.

Above - the BT-60 shot with gray filler/primer.

After sanding with 400 grit.

New Way Letter - Go Build, Part 8, Sanding the CWF & Filler/Primer

Here's the tube fill after working the CWF into the seams.

I usually hit the filler with 400 grit on a sanding block to start.

Take a close look at the end of the launch lug. That edge is rough and needs same sanding with 400 grit on a block.

On the left, there is already sanded CWF filler in the lug.

After sanding the ends clean, use a sharpened dowel to round the lug and clean up the inside wall. 

Thin strips of masking tape kept the filler primer of the root edge gluing areas.

On the right is the tube after sanding the filler/primer and pulling of the masking tape strips.

New Way Letter - Go Build, Part 7, Tube Seam Fill

I like to mark the tube spiral indents with a sharp pencil. It makes them easier to see when applying the CWF filler.

I dip just the tip of my X-Acto knife in the thinned CWF filler.

You won't need much, so wipe the excess off the back of the knife tip.

Run the tip into the seam recess with a back and forth motion. The blade directs the filler into the seam.

I dip and fill about one inch at a time.

I had hoped the plywood fins would only require some filler/primer to fill the very shallow grain.

There were a few "splinters" that needed some CWF and sanding.

Estes Advanced Target Drone, Kit #1913, Build, Part 5, Engine Mount Gluing & Filler Primer

The engine mount is glued into the main airframe tube.

The end of the mount is even with the end of the BT-50 tube.

I used the flat face of my sanding block to push in the mount.

The fins grain and body tube seams got the usual CWF coat and sanding. 

Just the leading edge of the four fins was rounded.

The fins and launch lug were sprayed with filler/primer.

After it dried, the fins were flipped over and the other side sprayed. 

The nose cone and body tube were also sprayed with filler/primer.

The yellow Apogee nose cones do need some undercoats so the yellow tint won't show through the final color.

Aerotech Mega Initiator #89541, Part 4, Tube Fill And Prep

The presentation model main airframe tube got the seams filled. The picture shows the thinned CWF applied. The tubes will still get a good shot of filler/primer and sanding to complete the two-step fill. 

Even with the heavy walled tubes, you can still get some extra support by sliding in the coupler. This prevents any distortion of the tube when sanding at the weaker fin slot areas.

The engine mount tubes are sanded for better adhesion of the centering ring epoxy.

Here's that "zero end" metal straightedge, no rounded overhang.

It's easier to accurately position centering rings when you can get the ruler edge against the ring wall.

Don't glue the rings on yet. This was just a test fit.
 

Estes Star Seeker (Tri-Pack) Kit #0866, Part 3, Filling Seams & Gluing On Dowels

The body tube, dowels and launch lugs were CWF filled and sanded.

A dowel was slipped in for support while sanding.

A shot of filler/primer followed .

Here I'm sanding the filler/primer to surface with an old piece of 400 grit. Any filler/primer that might collect on the sandpaper can be cleaned off under running water with a soft brass wire brush.

Two of the four fins are marked 1" down from the top edge.

This is where the perpendicular fins will be glued on.

I found it easier to mark a 1" span on a scrap piece of cardboard, then set the fins on the pencil lines.

Here's the first try at the 1" long dowels.

Looking at the instruction drawings, I could tell they were too short. There are no launch lug or dowel lengths listed in the instruction parts list.

Here's the longer 1 1/4" dowels.

I now have the feeling the dowels should be a smaller diameter. Oh well, I'm going with what I've cut.

(Edit: The dowel diameter I used was 3/32" diameter)

Enerjet by Aerotech Strong Arm Build, Part 9, Filling The Tube Joint

Here's the tubes together, the coupler inside glued together using 15 minute epoxy.

The pencil lines are lined up before the glue sets up.

 

Most of the joint gap was first filled with CWF, the excess smoothed out using a single edge razor blade.

The picture shows the joint after the CWF was sanded to surface.

The high spots end up fuzzy after sanding.

I wipe on some medium CA Super Glue using a Q-tip applicator.

After it dries, sand using 400 grit on a block.

A final fill is a shot of filler/primer and sanding with 400 grit.

Taking these extra steps, you shouldn't see the tube joint seam on the finished model.

Enerjet by Aerotech Strong Arm Build, Part 5, Tube Seams

   

Back to the Enerjet by Aerotech Strong Arm build. 

To see the first four posts: CLICK HERE

I had to go back and do a little more CWF fill where it fell out of the seam. This happens on occasion. I mark them as I find them using pencil.

After sanding the CWF to surface,

The tubes got a shot of filler/primer.

Notice the masking tape set inside the tube end to keep the interior surfaces clean.

On the right is the same tube after sanding. Filler/Primer fills what seam lines were left after the first CWF pass. Only this two-step fill is necessary.

The edges of the tubes got a wipe of CA glue using a Q-tip.

Use your fingers as a depth gauge keeping the CA line even.

The centering ring glue fillets are up inside the tube, not near the CA'd edge. Wood glue or epoxy won't soak into the tube if the CA glue has sealed it off.

The tube ends are sanded after the CA glue dries. 

This gives you a hard, stronger edge tube.

Enerjet by Aerotech, Arreauxbee-Hi, Part 4, Plastic Parts Prep

There are mold lines on either sides of the nose cone tip.

Sand the high spots first while maintaining the roundness of the cone taper. Don't sand flats into the curved sides. You'll be left with the lower seams below the surface.

These dips were lightly marked with pencil.

I used my Dollar Tree CA glue as a filler.

Draw a bead of glue down the line and let dry. Only use the glue on one side and let dry before using on the other side. Set the nose cone on its side for the glue to dry. Bear in mind, the glue can and will run if it is not allowed to dry horizontally. It will take a while for a CA glue bead to dry.

After one side dries, turn it over and apply to the other side.

Sand the dried glue with 220 grit then 400 grit to smooth.

There were some molding lines on the flat faces of the fins.

Sand with 400 grit on a block.

Bad Tubes?

If you ever built a vintage kit from the 1970s, 80s or 1990s -

You probably noticed the body tubes were of higher quality than what you find in kits now.

Tubes felt stronger and the diagonal wrapped seams were narrower and tighter.

Euclid Spiral Paper Tube company is now under the Paramount Tube name. The older, experienced tube maker employees have probably retired.

Some of the newer tubes have more than one outer seam to fill. 

Layers underneath bulge at overlaps. The outer glassine layer sometimes shrinks into the wide seams underneath. On some tubes, the glassine layers didn't get enough glue and look like they can easily be peeled off. 

I've heard stories of vendors refusing orders of bad tubes.

Some of the crap tubes have showed up in kits.

 

Here's an example - 

The clear outer glassine was sucked into a seam gap underneath.

It was wide and deep and would have shown under final paint. A coat of filler primer won't fill this spiral recess. I ended up cutting through and removing the glassine strip. 

On the left you can see the layer removed over the seam gap.

On the right, the tube has been lightly sanded and the usual joint seam marked with pencil.

Both seams have been filled with CWF.

On the right is after sanding the CWF to surface. Notice the irregular tube surface that shows when the tube is sanded.

I followed up with a coat of filler/primer and sanding to get the tube smooth for color coats.

This is not the fault of Estes or other vendors. The quality of some Paramount Tubes is just poor.

Enerjet by Aerotech Initiator Build, Part 4, Body Tube Bubbles

Body tubes are not what they once were. 

This is not blaming Aerotech or Quest. 

The supplier - Euclid/Paramount make the tubes for all vendors. When Paramount bought Euclid, the quality dropped. 

There were a few raised air bubbles that will show thru on the finished model. They don't show in the photograph but you can feel the raised area with a fingertip. I marked the raised areas with pencil.

I had mixed results using the technique shown here.

I slit the outer white layer with a sharp knife.

A bead of medium super glue was run over the slit. A few seconds for the CA glue to run into and spread out under the slit.

Before it set up, the excess was wiped off.

As the glue dried, 

A Sharpie barrel was quickly rolled back and forth over the glued slit. 

Here you can see where the glue has seeped under and around the slit.

This closed up the bubble pulling the raised center area down and onto the tube.

Most all of the bubbles and slits will disappear when filler/primer is sprayed then sanded. A few of the bubbles needed a second treatment with the Super Glue.

Enerjet by Aerotech Initiator Build, Part 3, Parts Prep, Nose Cone & Body Tube

The tip of the nose cone has a small bit o molding flash (left side)

On the right side the tip has been sanded and rolled off. Start with 220 grit and go progressively to 400 grit.

The nose cone molding seam was filled with plastic model  putty.

You can also lay a bead of medium Super Glue down the recesses. Be careful, the glue can run.

Sand down the filler bead of glue again with 220 grit working down to 400 grit.

The main body tube wrap seam was filled with CWF and sanded to surface.

Follow up with a spray of filler/primer and sanding with 400 grit.

There is more on the body tubes in the next post.

Semroc Wac Corporal Build, Part 6, Launch Lugs

On the left are the laser cut, kit supplied launch lugs. The edges are burnt and rough.

I cut new lugs from some extras I had. 

The seams in the launch lugs were filled with CWF at the same time as the body tube.

I slide the lugs onto a Q-Tip for a holder when brushing on the filler.

Leave the lugs on the holder when sanding the CWF to surface.

Some CWF filler may have gotten inside the lug edge. You don't want the lugs to get hung up on the launch rod.

Clear, clean up and round the lug by rotating a sharpened dowel in the lug ends.

Estes Condor #0807 Build, Part 16, Gluing Up The Wing Dihedral

I taped the dihedral guide pieces to my work surface. Otherwise the thin cardboard pieces will flop and fall under the wing halves.

After the glue dried there was a small gap where the two sides meet. This is on the bottom seam of the "V" shaped wing.

Some CWF filler was ran down the seam and sanded.

Filler/primer was shot down the center filled seam only.

The bottom of the "V" was carefully sanded.

The wing is ready for fitting under the fuselage.

Estes Great Goblin, #9724 Build, Part 15, Nose Cone Prep & Fin Gluing

The slight raised molding seams on the nose cone can be scraped down using a knife blade. 

TIP: Use the back of the blade (dull side) like a cabinet scraper. Why dull the sharp side of the blade when the back can knock down the high spots?

Note I said "high spots". You shouldn't shave into the trough, recessed areas of the mold seam. If you scrape down below the curvature of the cone you'll see "flats" when the paint is applied. 

After scraping the raised seams, sand smooth with 400 grit. 

The remaining recesses should be filled. If they are deep you can use Squadron Putty or medium CA glue.

If the seams remain shallow, the filler/primer should fill them.

Getting the center out of the nose cone eyelet took some time.

I punched small slots using the tip of my knife blade until it could be pressed out.

On the right side picture - 

TIP: Those jagged edges should be smoothed out using fine needle files. Left rough it could wear through the shroud lines and shock cord.

The instruction illustration shows wood glue on the sides of the fin. Too much glue will squeeze out and leave you with a mess to clean up. 

On the left - 

Showing the glue bead I applied. It's probably less than most builder's would use. The rest of the gluing will be done along the outside root edge fillets.

This is a very strong mount - 

1. The TTW tabs are locked, butting against the flat face of the first and third centering rings.

2. The notch in the fin interlocks onto the center centering ring notches.

3. The engine mount was already well glued inside the main airframe tube.

Some builders might want to upgrade the parts. Using the recommended engines, the engine mount and fin can assembly are plenty strong.

As the fins are being glued in place,

Sight across the rear to be sure they are in line. Here you can see how the farthest fin is not in line with the closest fin. Make all adjustments before the root edge glue sets up.