Last Saturday, my 8-year-old son participated in his first Space Derby with his Cub Scout pack. Many Cub Scout boys, parents, siblings, and leaders attended the event. What is a space derby? Well, it’s probably a little different than you imagined.
Each Cub Scout receives a Space Derby kit through their Cub Scout package. The kit consists of balsa wood that each participant will use to form the body of a rocket. There is also plastic material in the kit that can be cut to create fins for the rocket. This is where it starts to sound a little strange. There is also a propeller in the kit. To the propeller? !! I thought this was a rocket. Well, it’s supposed to look like a rocket, but the propeller actually propels the rocket. Cub Scouts compete with their rockets four at a time. The rockets hang horizontally from a fishing line and the propellers are powered by a rubber band that comes with the kit.
Rockets are judged in three categories; speed, beauty and originality. It quickly becomes apparent that the main thing that makes a rocket fast is its weight. Since all rockets work the same way and roll equally, the lighter the rocket, the faster it will go. However, if you make your rocket lightweight, you risk structural failure when the rubber bands are rolled up. So there is a balancing act between having a light but strong rocket and having a fast one.
My son and I decided to go for the beauty category as this was his first space derby. We wanted to get an idea of how the other rockets would behave in terms of speed this time. We follow the instructions in the kit and begin by gluing the two balsa wood halves. Later we use very thick sandpaper to start making the shape of our rocket. I later learned from some of the other parents that a potato peeler works wonders for cutting wood from the body to get the rough shape of the rocket. Not having this information to begin with, we used sandpaper. Once we got the basic shape we wanted, we used finer sandpaper. We switched to 400 grit sandpaper, then finally 800.
Next, we spray the rocket with primer. Once the primer dried well, we sanded it with 800 grit. Then we added another coat of primer and sanded it again. We continued this process until the rocket body was smooth enough to satisfy us. I have a friend who said I should have used primer for sanding. He says he would have filled in the cracks in the balsa wood with just a layer or two. I’ll have to take his word for it. I used regular spray paint primer … the cheap thing.
Once we are done priming and sanding, we spray a coat of apple red candy on the body. When spray painting, there are a few tips that will make a big difference in how your finished model will look. Spray paint only in a well-ventilated area. It is important that you hold the spray can at the correct distance from your model … about 6 inches is generally recommended. If you bring it too close, your paint job will smear; too far and your paint job will have an orange peel effect (it will look rough and dull). Keep the can moving while you spray … again, spending too much time in one spot will result in runs and a not-so-great paint job.
By spray painting your rocket, you can create a support for the fuselage with a clothes hanger. This is because you get spray paint on your hands and fingerprints are left on your new paint job. Make sure you have a safe place where you can put the end of your hanger, preventing fresh paint from touching anything until it dries. Allow sufficient time for the paint to dry (30 minutes) before adding a second coat or (2 to 4 hours) before touching the body of the rocket, depending on the humidity.
Once the first layer is dry, we add a second layer of apple red caramel. We paint the fins and the chrome of the propeller after priming them. Since we didn’t have any useful stickers, I used silver and black Sharpies to draw lightning bolts on the mailing labels. Then I cut the rays and glued them to the body of the rocket. My wife used a fine point black marker to add Capt. Justin Rodgers to one of the rear fins of the rockets.
Justin’s rocket won first place in the beauty category. It did well in terms of speed, but we will definitely build a lighter rocket next year. Hope you found some helpful tips in this article to build your own winning rocket ship.