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Badd Azz Rocketry Defender MKIII

By Richard Evans

Badd Azz Rocketry Defender MKIII

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The kit (2013-05-12 19:18:21)


54" in length

4.5 lbs built

38mm machined aluminum motor retainer

Machined aluminum bulkheads

Machined UHMW "ramjet" nosecone with aluminum bulkhead.

Fiberglass body tubes, fins and AV bay

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The kit as shipped (2013-05-12 19:21:50)

Everything included except the electronics, adhesives and motor!

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The body tubes (2013-05-12 19:27:28)

The body tubes had a glossy finish. 60 grit sandpaper followed by 120 grit is much better for painting.

The rocket could be built unfinished.

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Payload bay primed (2013-05-12 21:19:14)

Payload bay sanded, primed with DupiColor adhesion promoter, primed with RustOleum primer.

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Fin install prep. (2013-05-12 21:23:04)

Fin mounting prep. The fin tabs will be flush with the inner tube (or bout) when mounted.

I test fit the fins before epoxying. The fin slots were a bit on the narrow side. I used a drill bit that just fit into the slot to SLIGHTLY open it up by moving the bit by hand back and forth inthe slot. Do not enlarge the slot too wide.

The root of the fins and body tube were sanded with 60 grit and alcohol cleaned.

The forward centering ring and shock cord have already been installed.

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Fin install (2013-05-12 21:24:30)

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Fin installation (2013-05-12 21:28:47)

Fin alignment with a plumb bob.

Mix up a very small amount of 15 minute epoxy to tack the fins to the body tube. "Butter" the bottom of the fins and slightly up the sides. Insert into the slots and check alignment with plumb bob. Let it COMPLETELY set up before doing the next fin.

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Fins tacked (2013-05-12 21:30:32)

All fins tacked in place.

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Taping off fillets (2013-05-12 21:38:32)

I will be using a short piece of 3/4" PVC to draw out the fillets. Use tape to mask off where the fillet will be.

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Fillets (2013-05-12 21:46:15)

First filets laid in. G-Flex and Cabosil used.I used a piece of 3/4 PVC pipe to draw out filets. This took two passes, wipe the PVC off after each pass.

Let the epoxy run over the forward and aft parts of the fins, this will help when "moulding" the fillets.

Remove tape after epoxy gets tacky.


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Fillets sanded (2013-05-12 21:48:39)

Filets done and rough sanding. The G-Flex and Cabosil sands fairly easily. I will slightly round over the fins with 120 grit.

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Close up of fillets (2013-05-12 21:50:33)

If you take your time with sanding the fillets,they will look as if they are moulded in.

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Aft end primed (2013-05-12 21:53:40)

Aft end primed. This will show any defects in the filets, most of the primer will be sanded off. The forward end of the fins needed some spot putty. The priming and sanding may take a few times.

I used a wooden skewer to hold the forward centering ring in place.

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Base color painted on. (2013-05-12 21:59:23)

The entire rocket was sanded with 120 then 320 grit, alcohol wiped down, adheasion promoter primed Primed with RustOleum primer and then primed with Duplicolor primer.

Let the primer dry for at least 6 hrs depending on the weather, wet sand with 400 grit, wash off with clean water, alcohol clean and tac off.

Base paint new Duplicolor Champagne Gold metal flake.

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Masking off (2013-05-12 22:03:55)

I masked off some striping where I wanted the gold to stay.

DO NOT SAND ANY METALFLAKE PAINT!!! Be creful when handling, metal flake paint will show any sratches etc.

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Cndy timw (2013-05-12 22:08:11)

Painted entire rocket with Duplicolor Candy Apple Red candy coat.

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Tape removed (2013-05-12 22:10:50)

Remove the tape within a few minutes of candy coating.


I sprayed 6 coats of Duplicolor clear over the rocket, waiting about 10 minutes between coats.

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Make it shiney (2013-05-12 22:17:15)

After the paint has dried for 24 or more hours, wet sand with 2000 grit. Dont over do the sanding, you dont want go sand through the clear coat. Clean with clear water.

I use Meguiars rubbing compound, polish and then wax.

If you take your time, the finish will be outstanding! The picture does not do justice.

I tried to paint the nosecone with no success, the paint will not stick to this plastic. I may try it again after more research on this type of plastic.

All the hardware installed, motor retainer and launch lugs.

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Fin detail (2013-05-12 22:27:45)

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