MAC Performance Scorpion - a build thread

The weather now is pretty good, but careful masking.... I've had issues in the past with testors and masking too soon.

this was in may though, and fairly humid if I recall.

How soon was too soon for that, Dave? What I've had happen when masking too soon was I'd get tape "prints" on the paint. But that can be corrected by wet sanding and clearcoating. I don't think I've even had paint lift with the tape before.

Your flying on this, looking great

I believe that was day after, using blue tape

I guess that's just about where I am. However, I found a partial way to expedite that.

As a point of detail and because I wanted something highly reflective on the rocket body to make it easier to spot, I decided to add some aluminum foil tape to the fin can area. This ties nicely (aesthetically speaking) with the spun aluminum Aero Pack boat tail. The fins are to be painted, as suggested by the earlier rendering, but I wanted the can itself to look like bare aluminum. I'm kind of going for a sounding rocket look, this part of the rocket is "unpainted". I also decided to have a bare aluminum band around the upper body, under the roll pattern. Call in the "telemetry unit" on the sounding rocket or something. Above that would be the instrument payload, below it is the motor. If it were a sounding rocket...

I bought some 2.5" wide foil tape at The Depot, which was a perfect width when spanning between 4 fins on a 3" diameter rocket. I started by wrapping a band around the diameter just ahead of the fins. Between the fins, the width of the tape allows the edges to go up the fillets about halfway, and has enough material to form around the leading and trailing edges at the root. So, the aluminum fin can conforms around the fins closely without having squared off spaces on the ends of the fins. These pieces between the fins are butted against the band ahead of the fins. Then the front band was applied. This all took some screwing around, some care, and fairly precise placement (not to mention a few choice words). As the tape was laid down, I could smooth it with my fingers and have it lay down well. I then applied 1/8" black pinstripe tape (which I happened to have) around the forward end of the fin can foil. This part of the rocket body is "vented", you see. The result:



By applying the foil tape now, it gives me a point of contact to apply masking tape, with contacting the still-soft paint from yesterday. So, I masked off the middle body, fin can, and two fins. And then I could spray the green.



Between my 2nd and 3rd coats, it started to sprinkle, so I had to relocate to the back porch. I don't think I got any overspray on the grill though... I'm afraid that there's no way around waiting for the green to thoroughly cure before masking, though. At least if I want to avoid the paint lifting that Dave pointed out. I did have that happen in a few small areas when I had to pull the foil tape up to reposition it. The adhesive on that is much more aggressive than the masking tape though...

It's looking good. What are you planning to use for rail guides?

With the most recent sale, I broke down and bought a dual deploy version of this. Arrived today. Beautiful kit.

Here's how it stands right now:



Still no recovery harness installed, and I still have to mask/paint the roll pattern, but I brought it out to a launch last weekend anyway. I hope to finish the basic painting this weekend, then get a clear coat on it. I'm not sure how well the clear will stick to the foil tape, but I have enough extra that I can experiment with it first before shooting the rocket as a whole.

I saw this on your table this weekend, beautiful job on the aluminum tape! I have aluminum tape on one of my rockets, and compared to yours it looks like it was put on by an angry monkey.

Man, I like that color scheme a lot! Kudoes!

DGBrown said:

compared to yours it looks like it was put on by an angry monkey.

Click to expand...

Best, line, ever.

Beautiful.

I'm also very impressed with your aluminum tape application, I don't know if I could ever get it so perfect.

LOL, this was put on by a perhaps slightly more patient monkey, but a monkey nonetheless. Had you picked it up and turned it over, you'd have seen some application "flaws". But you won't see them when its on the pad...

I will say that there seems to be a bit of a trick to applying the foil tape. Wrinkles can often be worked out (if not too severe) if you smooth it as you apply. You can even get it to conform a bit (it is pretty malleable after all) by working it with your thumbs as it's laid down. I figured that out when I did the nose cone on my Black Brant III. Actually, working it with the tops of my thumb nails (which is odd to do) seemed to work best. You need something compliant enough to let the material flow and not get marred, but firm enough to push it. I was also using the handle of my Testors hobby knife (with the cap on!) because it has a sort of soft-feel coating. OTOH, I did have a couple of panels that I had to peal up to reposition that got wrecked in the process, and had to be redone. Not waiting for the paint to fully cure, lead to that being pulled up in a couple small divots, like Dave showed previously. So, in those spots, there are bumps under the foil that are visible.

I wonder if the paint might have pulled up even if the paint was fully cured. The adhesive on that tape is quite strong...

In any case, you got at least one side of the rocket to look perfect so that's achievement enough in my book.

Today, I masked off the upper section of body tube and painted the roll pattern.

And with the mask off and the 1/2-sized decal from Stickershock applied:



I also received the swivel and quick links needed to put the recovery system together, so that part is done as well. I still need to 1) clearcoat it and 2) drill it for rail buttons and static ports for the altimeter. I did pre-drill pilot holes for the buttons prior to any painting, once I was certain where they'd go. So I just have to open those holes up. But the ports have to be placed yet; I will probably try to hide them in the black portions of the roll pattern.

I would almost be unwilling to launch it after that paint job! :wink:

That looks killer!

That will be an eyeball-grabber on the launch pad for sure. Fantastic job!

Thanks guys. Hopefully, it flies as good as it looks.

I'm pretty sure that this thing is crying for a green reload...

Looks great - nice scheme!

This forum needs a like button! Love the scorpion, what a beautiful build! Thanks for sharing.