This How-To Classroom series covers building a high-power rocket kit, capable of flights on H or larger motors suitable for level 1 certification or general sport flying. We're going to concentrate on good basic construction techniques for high-power rockets.

Let's start with a kit. Kits from good manufacturers provide a well-thought out and tested rocket plan, most of the materials to build it and good instructions. The best kind of kit for a first high-power rocket, and particularly a level one certification rocket, is a simple one. Choose a kit with three or four fins on the aft end and no fins forward. A "three fins and a nose cone" (3FNC) rocket is ideal.

Good first kits are available from many manufacturers, notably Public Missiles, Ltd. and LOC/Precision. The kit we will build in this series is the Yank Enterprises (now part of Loc/Precision) 4" IQSY Tomahawk (with 54mm motor mount tube). The kit you choose shouldn't be critical as we're going to concentrate on technique, and you should choose a kit which appeals to you.

Tools and Supplies

Many of the tools and supplies used in high-power rocketry are the same as those used in model rocketry (and modeling in general).

• X-Acto® knife and blades
• razor saw
• sandpaper in assorted grits (at least 60, 100 and 220)
• drill and bits
• screwdrivers
• masking tape
• ruler with a metal edge
• pencils and pens

Some other useful supplies for high-power rocket building:

• thread locker (Loc-Tite® or similar)
• palm sander
• Dremel® tool
• pliers and wrenches
• small drafting squares
• aluminum angle (as long as your longest tube)
• rubbing alcohol

Note that we are ignoring painting supplies for now and will cover painting supplies and techniques in the last installment of this series. (We will paint the rocket using spray cans for simplicity.)

Epoxy

Bonding deserves a special discussion. Most high-power rocket kits are bonded with epoxy rather than white glue (aliphatic resin). Epoxy is a generic term which refers to a certain type of two-part adhesives. One part is called the "resin" and one the "hardener." You mix the two together and within a certain period of time, which varies by the type of epoxy, the mixture solidifies and creates a very strong bond.

The epoxy most people start out with is "hobby shop" epoxy, often made by Bob Smith Enterprises. This epoxy is mixed with a 1:1 ratio (the same amount of resin and hardener) and comes in several versions. The most commonly used versions are 5 minute and 30 minute. The number of minutes refers to the "pot life" and is amount of time until the "gel" stage. When the epoxy gels it is no longer runny, but is still not "cured." Curing is the process of hardening and full cure can be an hour to days (depending on the epoxy type). Note that the times are very approximate and depend on the amount you mix and the ambient temperature. The 5 minute epoxy sets faster which allows you to work more quickly, but may not produce quite as strong a bond and will not penetrate porous surfaces as fully.

There are many epoxies available. Many people like to use the "epoxy systems" such as West System, FibreGlast and Raka. These systems all offer a much broader range of products, but involve a higher initial outlay. See the articles on epoxy in the INFOcentral CONSTRUCTION area.

For mixing epoxy, you need small sticks such as craft (Popsicle®) sticks. For larger amounts, it is also useful to have disposable cups, such as the Solo® plastic cups. Don't use Styrofoam or paper cups though. For mixing smaller amounts, a pad of 2" square Post-It notes works well. You should also wear latex or nitrile gloves when working with epoxy. Skin clean-up is best done with citrus hand cleaners like GoJo® or Fast Orange®. Tool and drip clean-up can be done with rubbing alcohol (70% isopropyl is fine).

Check Out Your Kit

Once you receive your chosen kit, open the box carefully, take out all the parts and find the instructions. Lay out all the parts on a safe surface and read through the instructions. Try to make sure that you have all the parts and understand how the rocket will go together. If you understand how the pieces fit together, you will be much less likely to make a mistake.

Make sure you have all the tools and supplies needed to build your kit. Sometimes the instructions come with a list of things you'll need and other times you'll have to figure this out from the instructions. Having everything ready before you start will make building the kit much more fun and improve your results.

The quality of instructions varies quite a bit between different manufacturers. However, the major manufacturers all provide reasonable instructions. They do expect you to know certain basic high-power construction techniques, which is where this how-to series comes in.