Model Rocket Building Blog

Estes Mercury Redstone #1921 Build, Part 1 Parts
  That's a LONG ST-20 tube at 19.5"!  Yes, I'm calling it a Centuri ST-20 tube. I like the single long tube instead of two pieces with a coupler. The Centuri kit had an ejection baffle at the two piece tube joint. This model is based on and uses the capsule and tower molds ...
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Estes Mercury Redstone #1921 Build, Part 2, Fins A
If you don't have one - get one! To shape fins a good sanding block is a necessity. This is the Great Planes Easy Touch sanding block. For specs, CLICK HERE I have the 5 1/2" long sander, plenty big enough for most rocketry projects. I buy their 220 grit on the self adhesive rolls. It feels ...
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Estes Mercury Redstone #1921 Build, Part 3, Fins B
I used white glue to laminate the main fin halves. Why don't I use yellow wood glue? White glue holds fine. TIP: Too much glue and things get slippery! You don't want to have the fin sides slip when set under a weight for drying. Squeeze the bottle and set down some glue. Quit squeezing the ...
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Estes Mercury Redstone #1921 Build, Part 4, Fins C
I've explained a few times before how to sand sharp angles on scale fins. On the Mercury Redstone, the leading edges are sanded to a wedge shape. To better see the "knife edge" thickness I like to blacken the leading edge. This gives a high contrast to the light beige balsa. A permanent marker ...
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Estes Mercury Redstone #1921 Build, Part 5, Fins D
I couldn't see the pencil line at the 1/4" taper width so I set down some masking tape. I don't always do this. It can help you to not sand over the high point. The fin rudder squares will be shaped first. Sand the top knife edge thickness (1mm) first. Just concentrate on the top edge ...
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Estes Mercury Redstone #1921 Build, Part 6, Fins E
The same sanding method was used on the four main laminated fins. On the left, just the leading edge thickness is sanded first. I haven't sanded down to the masking tape yet, just concentrating on the leading edge. The inset picture shows it sanded down to the tape edge. The full length of the ...
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Estes Mercury Redstone #1921 Build, Part 7, Fins F
The fin plates will need a sharp knife to remove them from the laser cut sheet. Don't try to punch them out. Sand the edges smooth removing the black soot. To help prevent de-lamination, run some medium CA down the edges. Don't get any CA glue on the flat surfaces, just on the edge. After ...
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Estes Mercury Redstone #1921 Build, Part 8, Fins G
The fin tip plates are centered and glued down the outside edge of the fin. The flat side of my sanding block is used to square up the back of the fin and the bottom of the fin plate. I tried to move and re-center a fin plate. The heavy card stock split. Lesson learned. It glued back together ...
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Estes Mercury Redstone #1921 Build Part 9, Decal Redraw For RED
A little break from the build to draw some decals. The provided decals aren't correct. I know, who'll know the difference, right? The reds are on the pink side, the UNITED STATES font is too bold, and the flight designation should be MR8. I'll try to get my decals a little closer. It's ...
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Estes Mercury Redstone #1921 Build Part 10, Capsule Assembly Part A
The Centuri instruction illustrations show the capsule and tower parts still on the sprue trees. In my kit most of the parts were separate.  Look close at the edges and smooth over any left over flash. Dry fit, dry fit, dry fit! (Did I mention dry fitting the parts?) There is three sides ...
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Estes Mercury Redstone #1921 Build Part 11, Capsule Assembly Part B
Here I'm evening up the capsule side edges before gluing. The antenna housing cap is dry fitted in place to insure the top alignment. Some "safe" plastic cements won't do the job. Try the Plastruct Plastic Weld liquid cement. With this type of glue you hold the pieces together then brush the ...
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Estes Mercury Redstone #1921 Build Part 12, Tower Assembly TIPS, Part A
I know, finally the Tower! When dry fitting, I had a heck of a time trying to get the tower sides to line up. The Estes instructions have you assemble the tower from the bottom up. In the Estes instructions you start by gluing the Antenna Housing cap on. You aren't told where to center the side ...
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Estes Mercury Redstone #1921 Build Part 13, Tower Assembly and Paint, Part B
Again, glue the tower sides together first. Don't glue the inverted "Vs" into the holes in the antenna housing rim. I followed the older Centuri instruction to assemble the capsule and tower. The Plastruct cement glued the first two sides together and dried quickly. On the left, a drop of glue ...
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Estes Mercury Redstone #1921 C Build Part 14, Capsule Assembly Paint Part C
EDIT: This white ring was replaced with a ring of aluminum Monokote trim later on. Some pictures (and my Dr. Zooch Redstone paper wrap) looked white. I should have checked Alway's Rockets Of The World and I would have had it right the first time! I added a ring of white decal paper to the ...
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Estes Mercury Redstone #1921 B Build Part 15, Tower / Capsule Assembly Part D
Here's a dry fit of the antenna cap Vs into the small dimples inside the three tower legs. The inset picture shows how the cap is turned very slightly. This is the only way I could get everything to fit and the tower legs into the dimples in the lower antenna hosing cap. Go ahead and glue ...
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Estes Mercury Redstone #1921 A Build Part 16, Tower / Capsule Assembly Part E
The antenna cap was glued into the tower. Run some glue around the antenna cap and press into place while lining up the inverted tower Vs with the dimples in the antenna housing bottom piece. Here's what too many builders have problems with when assembled using the new Estes instructions. The ...
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Estes Mercury Redstone #1921 Build Part 17, Tower & Capsule Details, Part F
After the last step you can see why it makes more sense to assemble the tower from the top down, not the bottom up. The tension fit and bend of the inverted Vs would make the tower gluing impossible to do with the legs bowing out at the top. After everything has dried, add a small bit of glue ...
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Estes Mercury Redstone #1921 Build Part 18, Fin Marking Guide
I didn't want to cut up the instructions for the fin marking guide. The fin, lug and DT lines were extended beyond the edges of the marking guide with pencil. A slightly smaller piece of copy paper was taped over that. Using the extended lines, new lines were drawn on the overlay paper. ...
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Estes Mercury Redstone #1921 Build Part 20, Fin Placement
The body tube was roughed up down to the bare tube with 220 grit. The sides of the fin closest to the root edge were also carefully sanded for better adhesion in the fillet area. Rough up the primer coat just a little bit down the side. I do this because the fins were shot with primer / filler ...
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Estes Mercury Redstone #1921 Build Part 21, Fin Fillets
The lugs were lined up with a ruler and double checked with a 3/16" rod. The kit supplied 1/8" diameter lugs were swapped out with 3/16" lugs. I felt the model was too large for the 1/8" lugs. Looking at the Mercury Redstone on display at KSC, you can see the rounded fairings on the lower 2/3rds ...
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Estes Mercury Redstone #1921 Build Part 22, Capsule Window
The first Mercury Redstone had an round window, this kit is based on the second Redstone launch and should have had a trapezoid shaped window. I can't paint the fins with all the Summer rain so I decided to cut in a more correct window shape. On the left is the molded round window. On the right ...
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Estes Mercury Redstone #1921 Build Part 23, Capsule Decals
I went to Alway's Rockets Of The World for decal placement. The kit only gives you one "UNITED STATES". I'll set it on the opposite side of the window as shown in the overhead drawing. The white decals are very hard to see on the decal sheets so they are outlined with a dashed line. The ...
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Estes Mercury Redstone #1921 Build Part 24, Fin Masking
Masking a Mercury Redstone is a bit deceiving. It looks like a such simple pattern. One hour into masking you think you are close to being done, then realize there is more tape to be set down! I did my typical Scotch tape masks at the color separation lines then brown masking tape outside that. ...
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Estes Mercury Redstone #1921 Build Part 25, More Decal Questions
To help with decal placement, go to the older Estes instructions: CLICK HERE Decal placement is at the bottom of page 7. The single, long kit body tube is 19.5" long. The older Estes instructions say the two kit tubes were the same length. The 1/4" wide black strip was placed over the body ...
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Estes Mercury Redstone #1921 Build Part 26, Still More Decal Questions
I don't know what this decal is for! It's the same length as the 1/4" middle band so I assume it simulates the bolts in the band right above the fins. The dashed line looks too thin. The older instructions say it's 1/8" wide. For right now I'll just add a line of black from some old decal ...
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Estes Mercury Redstone #1921 Build Part 27, Decals
The kit decals didn't have the 1/8" wide lower black bar. I cut mine from old decal sheets. Notice how the MR8 decal is set over the bar, no space between it and the black band. I used online pictures of the actual launch and Alway's ROTW as a reference. The low bottom line of the MR8 box ...
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Estes Mercury Redstone #1921 Build Part 28, Decals
According to the older Estes instructions,  The side of the roll pattern decal lines up with the left side of the UNITED STATES decals already in place. TIP: Notice the masking tape set inside the body tube. With a decal so close to the end of the tube, water might get inside. The masking ...
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Estes Mercury Redstone #1921 Build, Finished
  This is a big, impressive model when finished. It's probably a good thing I converted it for 24mm engines. I'll have to get the 18mm stock model C/G and add nose weight if needed. After all the extra work drawing up correct and red decals, I was glad to finish it. I understand ...
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Estes Mercury Redstone Capsule Tether Follow-Up, Part 1
On TRF, DMKeifer posted this illustration from the old Centuri Mercury Redstone instructions. I'm posting it here because I can't pull up the Centuri instructions on the JimZ website. It was about time I tied a 12" Odd'l chute to the capsule. There are two reasons for using this tie. 1. If the ...
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Estes Mercury Redstone Capsule Tether Follow-Up, Part 2
Here's something extra you can do on your Mercury Redstone capsule tower line. The white embroidery thread line can be camouflaged so it isn't seen. Set the white thread down along the tower and capsule. Using permanent markers, color the thread red over the tower area and black over the capsule. ...
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