The new Estes catalog came out today, and among other things, they're bringing back the Black Brant II, a scale model of the Canadian sounding rocket.
I love BT-55 sized rockets, and I love the look of the Black Brant II. I've wanted one for a while now. Until now, my two choices were to go to the work of making a clone, or searching eBay for an overpriced model. These were popular rockets, and they sometimes tend to go for more than I feel comfortable paying. Now I can get a new one directly from Estes.
From the "Estes Mercury Redstone Model Rocket" Facebook page
The Estes Mercury Redstone now has its own fan appreciation page on Facebook. It's not an official Estes-run page, but one created by an admirer of the rocket.
The Mercury Redstone kit is a recent re-release from Estes, and is part of what seems to be their return to a line of sport scale or semi-scale models of historic NASA rockets. The Mercury Redstone has been out for maybe a year now, and has been recently been joined by the Little Joe II (a Project Apollo test vehicle, used to test the Apollo Command Module's Launch Escape System), the gigantic Saturn V, and a low power version of the Nike Smoke sounding rocket (there has been a Pro Series II mid power version for some time). Soon, a Nike Apache kit will be released.
Also recently added to the Estes catalog is the Estes Shuttle, which, while not actually a scale model, is at least somewhat inspired by the Space Shuttle.
Most of the rockets are more challenging to build than your basic Skill Level 1 "three-fins-and-a-nose-cone" sport model rocket, and they have some nice detail. They're also on the larger end of the spectrum of low power rockets, and, when well built, look nice on the shelf.
Fans of Chris Michielssen's Model Rocket Building blog will remember his detailed build series of the Mercury Redstone. It's a good reference for some of the trickier aspects of the build (the capsule and escape tower in particular).
I love that there's a Facebook page just for this rocket. It's pretty new (looks like it was begun on June 28), and could use some more pictures. If you have some, you should add them.
Back in Part 4 of my Skill Level 1 series, Building the Big Bertha, I talked about filling in those spiral grooves you find on your rocket body tubes.
My first build - Der Red Max. I hadn't yet learned that you can fill in those spiral grooves.
This makes the rocket look better (it doesn't look like you made it from a roll of toilet paper), and might even make it fly better.
In any case, I like my rockets to look nice close up, because they spend a lot more time on the ground than in the air, and I like to show off my work to people who come to visit.
Some people don't bother to fill in the spiral grooves, because you don't see them while the rocket is flying. But if you're fussy about rockets like me, you try your best (I usually make a few mistakes) to get all the details.
Since building the Bertha, I've refined my technique, and I want to share it here. I've now gotten it to where I can fill in those spirals quite effectively - and this technique requires almost no sanding. That's particularly important for me, because I've never managed to sand wood filler off a body tube without going through the smooth surface and raising a few paper fibers - which show up in the final paint job.
Here's how I now fill tube spirals, and I hope you find it helpful.
First, you need your old friend, Elmer's Carpenter's Wood Filler - the kind with the orange lid, which looks like this:
Get only this stuff for rocketry purposes. Don't get the other stuff - it's grainy and weird, and doesn't sand well.
As is often the case, I pick up a lot of my building tips from Chris Michielssen's blog, and that's where I got the razor blade idea, which I still use, but with a twist - plastic razor blades.
I didn't even know they made these until I saw them at a hardware store. I grabbed some, and thought I'd try them, and if they worked, I'd report here that now even kids can safely fill tube spirals using the razor blade technique. It turns out, these are even more effective for me than metal blades.
Chris uses a dull hobby knife blade to lay some CWF into the spiral groove (see here) with beautiful results. I haven't quite got the hang of that technique. Back when I was building the Bertha, I used a small paint brush to fill in the spiral with thinned CWF.
This technique was OK, but I had to overthin the filler a bit, and it wouldn't go evenly into the groove. There would be a lot of low spots, and I'd have to re-fill the grooves after priming and sanding the rocket, and it didn't always turn out great.
Now I use a medicine dosage syringe.
Pharmacies sell these mostly for measuring out cough syrups and other liquid medicines for children. They work great for getting wood filler into the grooves.
A good first step (again, a Chris Michielssen tip) is to use a sharp pencil to trace along the spiral groove.
Though not strictly necessary, it will help you see the groove clearly as you apply filler. Some grooves are deep and obvious; others are thin and very light. I pencil in all my grooves, just to be sure to have a guide line.
Next, you'll thin - slightly - some CWF. This shouldn't be as thin as you'll need it to paint onto the fins for filling. It just needs to be thin enough that you can draw it up into the syringe. I spoon some out into a small bowl, then add water bit by bit with an eye dropper. I stir until it's nice and smooth, no lumps. Continue adding small amounts of water and stirring until it's about the consistency of cake batter - or perhaps a little thicker, say, between cake batter and peanut butter.
Stick in the tip of your syringe and draw an inch or so of CWF into the syringe. Wipe off the tip of the syringe.
Use the syringe to dispense a line of CWF right into the spiral groove, about an inch or two at a time.
I should have worked in the other direction, so you could see the filler going into the groove. But it doesn't matter.
Next, you'll pick up one of your plastic razor blades.
A regular razor blade will work for this - essentially, you're using it as a little putty knife. But the plastic blade has a couple advantages, I find. First, there's no risk of cutting yourself - or the rocket. With a metal razor, I sometimes cut or scrape into the body tube a little with a corner, raising paper fibers - that won't happen with a plastic blade. Second, because the blade is plastic, you can apply downward pressure. So instead of just scraping off the excess filler, you can actually push the filler into the groove as you go.
The blade has a beveled face and a straight face. Leading with the beveled face, you apply pressure, and the edge of the blade flexes, flattening the filler and completely filling the groove.
Both edges of the blade have a flat face and a beveled face.
So with the blade, follow the groove and remove the excess filler.
See the edge of the filler? That will have to be sanded off later - unless you do this next trick.
What you're trying to do is two things: completely fill the spiral groove and minimize the sanding you'll have to do once the filler is try. This part is especially true for me, because I've never been able to sand filler off a body tube with ordinary sand paper and not mess up the surface. Apparently I'm alone in this, because I've never heard of anyone else having this problem. But in any case, sanding is a pain.
So I came up with this last little trick - the part of the process that makes it all even more effective, almost eliminating the need to sand when you're done. Using the pad of your finger, buff the filler you've just applied. This will take off any excess and smooth out the edges of filler left by the razor blade. Just buff lightly - across the groove, not with it.
You'll know you're removing excess filler because after a few times, a small amount of it will cake on your fingertip. You'll need to wipe or wash that off occasionally.
Let the filler dry completely, then check it to see if you can feel any bits of the groove that were not filled in, or any raised ridges you didn't buff off with your finger. You may find that you don't need to sand at all!
I always do sand, just for good measure, but now I only have to make a cursory pass over the groove, and sometimes I find a glob I accidentally got somewhere in the middle I have to sand off. Because regular sandpaper messes up my body tubes 100% of the time, I now use a sanding sponge - the finest grit I can find, which is 320.
The sanding sponge is soft and flexible, and conforms to the body tube, and it won't cut into the smooth surface.
That's it. You'll want to wipe off any dust before you prime and paint, but everything should be filled in perfectly, and the surface will be smooth and groove-free. If you notice any low spots you missed in the groove after you put on primer and sand it down, you can use a bit more CWF to fill those in - but I find with this technique I almost never have to do that.
I hope somebody tries this technique and likes it. I used to get so frustrated filling tube spirals, because I could never quite get them filled, and because when I sanded them down, I'd have scratches and bumps that looked terrible once the rocket was painted. Now this is a part of rocket building I enjoy.
Now if only I could find a way of filling wood grain on fins I looked forward to!
I tend to write really long posts, and this is no exception. But, if you're new to rockets, I hope you find something of value here to use in your rocket builds. If you're more experienced, I hope you at least find this amusing.
I'm finishing up one of my three latest builds - the Quadrunner, by Quest Aerospace. This is a cool-looking rocket, and has a cluster of four motors - that's a lot of thrust, fire, noise and smoke compared to what I've launched in the past.
Check out what the kit looks like:
I'd been eyeballing this rocket for some time. I loved the idea of clusters, even before I'd tried them out. My first was the Quest Magnum Sport Loader, which was a lot of fun. Even with only two motors, you get a much more dramatic launch than with a single motor.
Here's the video of the Magnum launching on two Estes C motors - slo-mo at the end:
The Quadrunner is a little pricier than the standard basic kits I'd built in the past - about $45. I got it for less, thanks to an Amazon gift card. But I was nervous about building this rocket. It's more complicated than a Skill Level 1 rocket, and I really wanted to make it look good. It has, of course, the cluster of four motors, which means that putting together the motor mount is more complex, and needs to be more precise than a single-motor mount. You need all four motors to be perfectly aligned.
The finished mount
This means measuring and gluing precisely, and then rolling the whole thing across the table to make sure it's not wobbly.
There's another part that goes in the middle - it holds the bolt in place you see in the above photograph, which will hold the motors in - this is in place of the usual hooks most beginner's models use.
This meant threading the bolt through two diamond shaped bits, attaching a Kevlar shock cord to the top, then pulling the whole thing through the middle of the four motor tubes - then gluing that in place.
This little bit keeps the motor retention system in place, and is key to assuring your parachute ejects. And it's a tight fit.
It requires some precise sanding to make it fit, and without a precise fit, the ejection gasses from the motors will escape out the back of the rocket. The nose cone won't come off, the parachute won't eject, and the whole thing will come crashing down to earth and destroy all your work.
Then there are the fins. They're two-part fins which you have to glue together to make one piece - something I was nervous about, as I was pretty sure it would be easy to get them crooked.
How on EARTH was I going to get these perfectly straight? And how was I to round the leading edges, with that
joint right there?? This was an area I really could have screwed up this build and made a shabby-looking rocket.
The joint here needed to be pretty close to perfect.
I thought of several options, since in the directions you're meant to lay them flat on waxed paper to glue them together flat. I thought no way that's gonna come out straight - it's gonna dry crooked! I finally emailed Chris Michielssen of the Model Rocket Building blog, to ask what he'd do if he built this rocket. I hadn't found any references to the build on his blog, but I knew that if anybody knew what to do, it would be him.
He gave me some advice - turns out he had built this rocket. He said that gluing them flat on waxed paper was a good idea, and then putting a book on top would keep things straight. I sanded a rounded edge on part of the fins, then beveled the trailing edges, and put them together.
So far, so good.
I took all the steps I've learned so far to make the rocket look (and fly) great - carefully filled in those spiral grooves in the paper body tube, filled and sanded and filled and sanded and filled and sanded the fins, attached the fins to the body as carefully and precisely as I could...
Ted Macklin's guillotine fin jig...
Totally worth the money I paid for it.
Hi, Ted!
I got the fins down perfectly, with no gaps between them and the body tube. Made the best glue fillets I'd ever done - I mean, guys, this thing was looking really solid. Carefully filled the seam in the nose cone with some plastic putty, then refilled when I saw a little divot in the putty. Got the thing as smooth as possible.
Was I going to let this little flaw in the nose cone go unfilled? Oh, no I was not!
Up to this point, I was really proud of what I'd done. I had to take it slow, but I hadn't made any major errors I was bothered with.
Then, I had to wait to do the painting. Or, so I thought.
It's been cold here in Bloomington, and my understanding was that you should never spray paint if it's below 50 degrees Fahrenheit. So I waited.
Then, on a warmer day, I primed the rocket. I used a new primer to me - Rustoleum Sandable Primer. I always use primer that's "sandable," but had never used "Sandable Primer."
Actually, this was my first mistake. It turned out fine, and I really liked the primer. But I had intended to use Rustoleum Filler Primer. This stuff has a "build" to it, and apparently it can fill in flaws in your work. I believe it's used to fill in gouges in a car's paint job. I had a few spots I wanted filled on the fins, and a few weeks ago when shopping, I had been looking at both the Sandable and the Filler Primers. I thought I got the Filler stuff. I realized only after priming the rocket that I'd gone home with the Sandable stuff.
Never mind - it worked great. A few minor flaws that perhaps could have been fixed with the Filler stuff, but after some rigorous sanding, it still looked pretty good.
Warmer than it looks - time to prime
Primed and sanded, ready for painting
Round about this time, I got a suggestion on The Rocketry Forum that you can, in fact, paint when it's cold outside. You warm the paint can with some warm water, run outside with the warm paint and rocket, do a light coat of paint, and bring everything inside to dry and warm up for a few minutes between coats.
I had a launch scheduled for Saturday (cancelled, in the end, due to rain), and I thought I'd have time to finish this rocket by then. I always like having something new to launch each time, because I don't have any other rocketeers to fly with - I launch with friends who are only interested because I try to make it fun for them. Basically, every launch I do is a kind of "demonstration launch," and I'm secretly trying to get one of my friends interested enough to start building and launching, so I have someone to talk rockets with.
I wiped the rocket down with rubbing alcohol to rid it of any dust, and did my undercoats of white. The rocket looked great. No problems due to cold weather - a nice, smooth, shiny finish.
It's hard to light a white rocket indoors, but you get the idea.
After letting the white cure for two days, I was ready to paint the red top coat.
This is where the trouble started...
Now, I was going to include this paint job in a post for my fellow rocket n00bs on the fact that you need to plan certain parts of your build, particularly painting, to avoid a messy job, and to keep from being frustrated. In the process, I learned that I have a lot to learn about certain materials with rocket building...
OK, so the Quadrunner comes with a paper mask for painting.
You're supposed to cut this out and apply it to the rocket, with the round half at the top, 1 5/8" from the top of the body tube, then extend the side lines of the mask down to the base of the rocket with masking tape. Then you mask off that whole section with tape and paper, spray the rocket red, and when you're done, you should have a beautiful half-red, half-white rocket with a nice round part near the top of the white side.
This presented a challenge. How could I be sure to get the mask centered and straight? If I applied it the correct distance from the top, how could I be sure that the part of the round top I started with was even the true center of that bit?
Well, I thought about it a bit, and came up with what I think was a pretty good plan, and I thought this is perfect blog material, too! What a smart guy I am!
First, I measured the bottom of the mask, finding the center of that line. Then, using a right angle, I drew from that point up the center of the mask, through the top.
To check my work, I did a little geometry to find the center of the semicircular top - and you can see was off by just a little bit. I made sure the line was straight up the center from the bottom to the top, and carefully cut out the mask.
I cut up the sides with my hobby knife and a metal ruler. I tried to rig up a tool to do the top round cut precisely, using my high school compass and my hobby knife. I think I found this idea in an old Estes or Centuri rocket design publication I found online.
This didn't work as planned, so I just carefully cut the top out with scissors. Not to worry - the black and gold stickers would probably cover any minor imperfections in the shape.
Then I found the centerline between two fins by measuring the distance between the leading edges of the fins and making a mark with a pencil. Then I drew a line all the way from there to the top of the body tube, and on that line, I put a mark 1 5/8" from the top.
Now I had a line on the rocket, and a line on the body tube. If I could get those lines to match up with the top of the mask at that little 1 5/8" mark, I knew I'd have the mask centered and placed correctly, and we'd be good to go.
See? This should work great!
I still think this is a good idea, despite what came next...
To apply the mask, temporary spray adhesive is called for. I have some Elmer's Craft Spray Adhesive, which is either temporary or permanent, depending on how you apply it.
I applied the adhesive to the back of the mask, waited three to five minutes for it to be less tacky, then applied it to the rocket. Success! I got it on perfectly!!
Then I built a beautiful, elaborate mask. It fully covered everything, yet would be easy to remove when I was done painting. I was feeling pretty good up to this point. Why was I so worried about this rocket? Now all I had to do was paint - this would be a cinch!
Doesn't look like everything's covered, because the edges are Scotch tape. But this was
a masking masterpiece, guys. Perfectly aligned edges, full coverage... Great work.
Then came The Ordeal.
To seal the edges, I did a quick pass of the white paint first. Then, to my horror, the edges lifted away from the rocket and began to curl up. Gahh!!! Stop it! Stop it!!
There was no way around it - I'd have to stop my work, remove all the masking, and start again the next day.
I carefully peeled everything off, and laid the paper mask flat. It was a little wrinkled, but the edges were mostly fine, so when it was dry, I laid a book on top of it to flatten it out and left it overnight.
I figured I hadn't used enough of the spray adhesive. So the next day, as soon as I got home from work, I started again. This time, I made sure to get plenty of adhesive on all the edges, and reapplied the mask. Then I built up the whole brown-paper-and-tape masking apparatus and started again.
Here's where I grew impatient. I skipped the white sealing coat (not best practices, but not what led to disaster), and went straight for the red. And what a red! Rust-Oleum 2X Apple Red - bright, shiny, smooth... This rocket was looking beautiful.
I waited for about ten minutes, then began removing the mask. I pulled off the tape and the paper, and the fins were a brilliant white. The line was clean and neat. I pulled off everything but the paper mask... and then the mask wouldn't come off!
I used fingernails and lots of swearing, but the thing wouldn't budge. I even tried to gently, carefully slide the tip of my hobby knife underneath the mask to loosen it. Nothing!!
I went from happy to pretty desperate very quickly. What should I use? Water? Goo Gone? Razor blades?? After several more attempts to just coax the thing off, I'd scratched through in a few spots to primer, and in a couple tiny places down to the white body tube, and I worried I'd even gone through the glassine coating to the fibers below.
A lot of people suggested water (until I mentioned breaking through the tube - then it became too risky), WD-40, white vinegar. Problem with all of these is that the paint had made the paper pretty impenetrable.
Finally, in frustration, I got out a sheet of 220-grit wet/dry sandpaper and went to town on this rocket. Probably a terrible idea, I thought, but at this point, I don't care if the finish is smooth and beautiful - I just want that red paper OFF OF THERE!
Now, I don't have this next part documented with pictures, because I was acting in desperation. I wetted the sandpaper, and scrubbed like hell. Then, the sandpaper started breaking through the paint. Then through the paper mask. Then, I could see the white paper underneath!
I had three thoughts: 1) This is a terrible idea, and this paint job is ruined, but I don't care. 2) Wait... Is this working? I can't believe this is working!! 3) Holy crap! I can't believe this isn't causing more damage to the surface than it is!!
After scrubbing and scrubbing with the sandpaper, I finally got the paper mask off!! There was still some residue on the white part of the rocket, but the cursed red paper was gone!
Flash! Aaaaaah! He saved every one of us!
OK, so how to get rid of the sticky residue? I mean, maybe the rocket wouldn't be perfect, but there must be some way to get rid of that stuff!
This is the point when Our Hero, inventor of the guillotine fin jig, rocketeer extraordinaire, stand up guy, and my Internet buddy Ted Macklin, posted those three magic words: Ronsonol lighter fluid.
According to Ted:
As long as this paint is sufficiently dry Ronsonol (which is actually
naptha) will not dissolve the paint. It will soften and loosen most
adhesives, especially those that are relatively fresh. A little Ronsonol
on a cotton ball should work, but test first.
Ronsonol? I think I have some of that!
So I searched in the depths of the darkest closet in my apartment, and found the Ronsonol. I dabbed some on a cotton ball, and began wiping down the rocket. Dudes, this stuff is AWESOME. Took the residue off so easily, and I could feel the smooth finish I'd started with below.
At this point, I was so happy, I did the Dance of Joy.
The rocket is on its way to greatness. I have some chips to repair, and I have to figure out how to safely mask off the red paint so I can retouch the white. But the ordeal is over. The Seal Team Six of rocket painting came through, and we are safely back on home ground - a little scarred, a little bruised, but safe for painting once again.
A Few Things I Learned From This
If you're a relative rocket n00b like me, here are a few things you might learn from my mistakes:
1. Paper masks = bad. Much better is a low-tack substance called Frisket Film. Also suggested possibilities would be vinyl drawer lining (though I'm not sure how low-tack that stuff is) and some kind of vinyl sign stuff. Still not sure exactly what this is called or where to get it.
2. If you're going to use a paper mask, make sure you use temporary, low-tack adhesive, not this "temporary/permanent" stuff.
3. Maybe make a photocopy of paper parts you need if you might accidentally destroy them while making a terrible mistake? I'm not sure how I'm going to cleanly cut a mask for repairing the white part, now that the paper mask is dead.
4. Ronsonol lighter fluid safely takes off adhesive residue.
5. Don't be impatient. If I'd found out about the lighter fluid solution before attacking my rocket with a hobby knife, I would have no repairs to do. The stickers would be on it right now, and after nearly a month and a half building, the rocket would be done and ready to fly.
