Friday, May 26, 2017

Corner Chip Fill - TIP

Well, we've all been there - the balsa grain runs in such a way that the trailing edge tip can break off.
If the tip break is small you can fill it.

Sand off some balsa dust from some scrap balsa. Don't sneeze.

Apply some yellow wood glue to the broken corner. Use wood glue for this, yellow glue can be easily sanded.

Press the glued corner into the balsa dust pile from all sides.
Let the balsa dust and glue dry.
Note in the inset picture that the dust and glue is a little larger than the chip area.

Here's the same filled corner after filling and sanding to surface.
Not perfect, but after the fillets are applied it won't be noticeable.

Carded Red Max Build, Part 5, Fin Skin Gluing

The upper picture shows the three layers viewed from the root edge.

Use your burnisher to round off the cut side edges. This won't be a full round like the folded leading edge. The burnishing just takes the squared edges down a bit.
Don't burnish over the root edge, leave that square and sharp!

Run a small bead of white glue down the outside and trailing edges of the fins. Let dry and sand lightly with 400 grit.

Repeat the glue bead again, let dry and lightly sand.
This seals the open edges and rounds them over a bit.

Thursday, May 25, 2017

New Kevlar Supplier, Part 3

This softer Emma Kites Kevlar can fray at the end.
Tie an overhand knot close to the end.

Here's the weird thing about the Emma Kites Kevlar.
Normally a square knot stays tightly together after being pulled closed. After tightening, the knot starts to loosen and open up!

It's easy enough to fix.
A small drop of white or yellow wood glue adds the right amount of grab and keeps it closed. Apply a small dot of glue and pull the knot tight.

Here's the knot after the glue dried. It is closed and tight.

TIP: NEVER use super glues on knots, whether it is a Kevlar shock cord or shroud line knot. Super Glues run down the line and away from the knot. When the CA glue dries it makes the cord and knot stiff, brittle and breakable.

Carded Red Max Build, Part 4, Fin Skin Gluing

Don't use liquid white glue to attach the skins! Use a glue stick.
TIP: Glue sticks don't over saturate the paper or card stock. They also allow re-positioning before the glue dries.

I use the colored (purple) glue stick so I can see if I have good coverage. Be sure to apply enough down the center fold and along the edges.

Set the skins over the rounded straight leading edge of the cardboard. Press the leading edge fold down on the interior cardboard edge first before smoothing down the sides.

Burnish the skins down onto the cardboard interior piece.
It's not necessary to set these under a weight or in a book to dry.

Be sure your knife blade is new and sharp so the backside skin won't tear when cutting.

After the fins dry, cut through all the layers down the fine line on the "Root Edge" side.
The inset picture shows the other side of the fin. The back side is printed oversize to be sure the red ink covers edge to edge.

Wednesday, May 24, 2017

Carded Red Max Build, Part 3, Fin Skin Folding

To emboss the leading edge fold line sometimes I use the back side of a single edge razor blade. The sharp side is taped over with layers of masking tape.
Any rough burrs are sanded off before embossing.

You might find it easier to use the tip of a dull butter knife to emboss the leading edge fold lines.

Emboss the leading edge fold before cutting out the fins.
Lightly score the center lines using a straight edge.
Cut out the fins outside of the red image area. The white edges will be cut off after the overlay skin is glued to the center core.

Notice the ink coverage one side is larger. This ensures full ink coverage on the backside of the fin when it is cut out.

Pre-fold the leading before gluing over the center core. As always, I'm using the back end of a Sharpie barrel as a burnisher.

New Kevlar Supplier, Part 2

For a while, FlisKits included braided Kevlar in their MicroMax kits. Braided Kevlar is made up of smaller lines, is softer and more flexible. The braided Kevlar will burn through and break quicker than the twisted line.

Here's how the Emma Kite line is shipped. The label is marked: "1,000 feet - 150 lb. - Twist".

Will this line be better than the stiffer line from The Thread Exchange? Time will tell!
My past experience with the stiffer 135 lb. line is it will last for about 20 flights before breaking, usually right above the engine mount. That's one reason I developed a "Replaceable Kevlar Engine Mount" CLICK HEREIf Kevlar is tied beneath the upper centering ring of an engine mount there is no way to tie on a new line once it breaks.

Emma Kites includes a snap swivel with each spool of line. I don't know if I can use this style swivel on a rocket but I'll hang onto it for now.

Tuesday, May 23, 2017

New Kevlar Supplier? Part 1

NOTE: Before you order any Kevlar line from this supplier - Emma Kites, 
PLEASE WAIT and read the third post in this series. There is a concern with this Kevlar that some might have trouble with.

I had known about for quite some time. They sell Kevlar line for kite flying.
They are much cheaper than or
I was running low on the Kevlar I had bought from The Thread Exchange and this time ordered through Emma Kites.

On the left is 135 lb., #346 Kevlar from the Thread Exchange. I usually buy it in 4 oz. spools that are 264 yards for $37.00.
On the right is the Kevlar from Emma Kites. This is 150 lb. line, 1,000 feet for $23.00.
The Thread Exchange line (bottom) is three strand and a bit stiffer than the Emma Kite line on top. The Thread Exchange line is very similar to what you would find in a Quest kit.
The Emma Kite line (top) is made up of finer lines twisted into three strands. Those three strands are twisted into the final line. The Emma Kites Kevlar is close to what you get from The Kevlar Store.

Contrary to what some believe, Kevlar line can burn and degrade after many ejection charge hits. It's fire resistant, not fireproof. I did a very unsophisticated test holding a burning match under each line. Repeated match burn tests had both catch fire at about the same time.

Carded Red Max Build, Part 2, Fin Core Prep

My early art layout page had a LOT of extras. The body tube wraps are printed on 20 lb. paper, the fin overlays are printed on 110 lb. stock.
Lightly spray the print side with clear acrylic. The model will get a final coat of clear after it is assembled.

The center core of the fins is cereal box cardboard.
Here I'm cutting of the edge to have a straight leading edge of the fins.

After the straight edge is cut, run some 400 grit over the edge and round off the top. It doesn't take much, just knock off the corners.

With some 220 grit sandpaper rough up the glossy printed side of the cardboard for better adhesion.

Monday, May 22, 2017

Carded Red Max Build, Part 1, Parts

I've seen a few pictures of "Rocket Families" on the forums. The Red Max is a favorite with the Estes Mini Max (BT-50 based), standard Red Max (BT-60 based) and Mega Red Max.
Well, how about a smaller BT-5 version for 13mm engines? This one is tiny at just 5 1/4" tall! It performs like a BT-5 Mosquito.

At one time I had a little carded Red Max model. It was a BT-5 diameter with a Micro Max engine mount. I lost it somewhere along the way and wanted to make another one.
After a few searches I couldn't find it. I thought it might be at Wayne Hill's Rocketry Blog - CLICK HERE 
There are many carded rockets there including my designs.

The carded Red Max I had before had three piece laminated fins. The redraw I did has two piece "butterflied" fins where the center fold becomes a rounded leading edge. The center core is cereal box cardboard.

The decal art was taken from the online instructions at Jim Z's, cleaned up a bit and reduced.

Don't use the illustration at the right to make the rocket.
Email me at: and I'll send the full size PDF.

Two prints are made, on on 20 lb. paper a second on 110 lb. cardstock. This print gives you enough to make two rockets or have some extra parts.

PARTS: You'll also need some BT-5, a plastic Quark style nose cone, 1/8" diameter launch lug, 65 lb. Kevlar and a 13mm engine block.
TOOLS: A sharp knife, a dull butter knife for scoring the fin leading edges, clear acrylic spray, white glue and a glue stick.

Sunday, May 21, 2017

Mars Lander Embossing?

On TRF a post was made about the quality of the embossed pieces of the Semroc Mars Lander.
I noticed the embossed lines weren't as defined as my original Estes Mars Lander but it wasn't a deal breaker.

I would assume the Estes embossing was done using a combination of heat and pressure. This gave slightly deeper, more defined lines. The Semroc re-issue kit may have used a simpler pressure embossing. This is just a guess on my part. Years back I worked in a print shop and saw some heat embossing done.

The only place where the embossed lines totally disappeared was on the landing pads. The thin band in the center "sandwich" did have lines until glue was applied it was wrapped.
I re-embossed the lines using a small jeweler's flat screwdriver.

I thought a few of the TRF posts were harsh. I applaud Semroc for bringing back such a complicated kit.

Goony X-15, Part 11 Comparisons

Here's a comparison between the Quest X--15 and my Goony version.

I didn't use as many decals on the nose cone.
To be honest, the Quest decal sheet had all those little decals in different areas on the decal sheet. A real pain to place all those tiny details. On a Goony it's not really needed.

Here's all the tiny decals I didn't use on the Goony!

In 1988, Estes had a stumpy NASA X-15 kit #0889.
The side fairings look great but were probably hard to form out of cardstock.

Saturday, May 20, 2017

The "OLD" Estes Trident D.I.Y. Decals

In a recent comment on the Decal post, Naoto Kimura reminded me about the decal treatment on the original Estes Trident kit:
"The instructions mention "decal" but wording seem to imply that they weren't water slide type. The Trident instructions does mention using adhesive tape for the markings (so it appears decals weren't included)."

I built an original Trident kit in the mid 1970s. I was disappointed to find decals weren't included. Estes gave some direction on how to make them by spray painting Scotch tape red!

Really? I doubt many kids had a spare sheet of glass handy. Who would want to spray paint the back of your metal ruler?
To see the original kit instructions, CLICK HERE

The instructions also mention the Trident symbol can be "Hand Drawn in enamel or India ink." I bet that came out real nice. India ink would bead up on a gloss white surface.
Back then I did do the painted Scotch tape trick with mixed results. It was okay but felt too thick.
This was in the days before trim Monokote. I have spray painted white decal sheets and cut off strips to make water slide decals. 
The re-issue kit from Semroc has the water slide decals as shown near the bottom of the old instructions.

Goony X-15, Part 10 Decals and Finished

Before applying any decals the model was polished. The metallic finish is a bit rougher than a gloss would be. I wanted to be sure there wouldn't be any silvering of the decals.

This one actually came out pretty well!
Except for the length of the side strakes, all the fins were the same ones used in the old Quest X-15 kit.

Look close at the USAF in this bottom view picture. There's a little silvering of the decal. It looks like the decal didn't adhere around the "A". Oh well!

Friday, May 19, 2017

Still Interested In That F-16 Kit?

Odd'l Rockets F-16 kit is popular but quantity is limited, Hans - 

Occasionally I go to EBAY to check model kit listings. Last week I saw the Odd'l F-16 and clicked on it without looking at the vendor name. It turns out the vendor was

EBAY just sent an email to let me know that quantity is limited!
Thanks EBAY, but I'm pretty well stocked.

Goony X-15, Part 9, Nose Weight

This one might be okay without any added nose weight but I'll play it safe and add a 1/2 oz. of clay.
I had already set the screw eye in the nose cone base. I unscrewed it along with some balsa from the shoulder.

I've never drilled out a nose cone for weight before! In the picture you can see the decals were already placed. Decals are shown in the next post.

The screw eye hole acted like a pilot hole. I started with a 1/8" drill and worked up to a 1/2" diameter drill shown at the right. Don't go too deep!

There was some balsa glued on the threads of the screw eye. I could have found a new one, but I'm cheap.
The balsa was filed out of the threads with a small diamond file.

1/2 oz. of clay was pushed into the nose cone hole.
The screw eye was screwed back in towards the outside of the shoulder. Turn the screw eye so it will clear the body tube when the nose cone is inserted in the tube.

Thursday, May 18, 2017

Paper Cuts?

On Facebook, Mario Perdue posted a link to a very interesting cutting wheel made from two layers of paper.

On the video the paper wheel cuts through plastic, wood, dowels and corrugated cardboard.
Interesting to watch but I'd be concerned the paper might come apart at high speed. This would be one of the times I'd wear goggles. It could work in a pinch.
I don't think Dremel wants anyone to see this video!

To view it: CLICK HERE  

Goony X-15, Part 8, Black Paint Switch

So . . . you paint it black! No masking, just black.

I know, it should be flat black. But, there are water slide decals.
You can't get great results placing decals on flat paint. "Silvering" occurs where the decals can't fully adhere to a rougher flat finish.

I wasn't that excited about the gloss black. So much of the fin lines are lost. I hit the model with one light coat of Rustoleum Metallic Black.
What a difference! I'm getting farther away from scale but it's a Goony! Who cares?

Wednesday, May 17, 2017

That Star Blazer Canopy (Plus Two More) Apogee POF Article

Instead of the build post on the Goony X-15 I'm going to refer you to the newest online issue of the Apogee Peak Of Flight Newsletter.

This article shows how to do a step by step carving of the old Estes Star Blazer canopy. The techniques shown in the article can be applied to a one of a kind carved canopy on your rocket design.

On the current Goony X-15 a canopy had to be carved from basswood to make a master for the vacu-form process. That canopy took much more work carving out the concave bottom to fit over the nose cone curvature.

To read the P.O.F. article: CLICK HERE
The Estes Star Blazer was covered on this blog earlier in the month: CLICK HERE and CLICK HERE

Tuesday, May 16, 2017

Goony X-15, Part 7, White Undercoats And Sanding

Grey primer really shows off all the rough areas a glue blobs. The follow up white undercoat shows off even more.

Check out the rough fillet area under the strake.

Trying to apply a glue fillet in the very tight back fin angle is very hard to do. Sometimes I don't bother with it.
The same goes for launch lug fillets. It depends on how tight the angle is.

I've sanded down the rough fillets with 400 grit. Another white coat will follow.
This one will be easy to paint, it's all black!

Goony X-15, Part 6, Gluing It Together

Here's a view from the back showing the fin position. You can see the angled root edges to fit against the body tube.

Now it's starting to look like an X-15 - well, sort of.
White coats are next.