These techniques are collected and written for beginners, BARs or anyone
who has questions or might be looking for new construction ideas.
Most methods I've learned in over 40 years of trial and error.
Other tips I've picked up from Internet sites and Rocketry forums.
I'll try to give credit where credit is due.
I'm sure some will disagree with my building techniques.
And, many of these methods have been written about many times before.
But, if somebody picks up a few new ideas, it's all worthwhile.
All these techniques can be applied to model rocket kits and scratch builds,
Low to Mid power rockets, powered by A through F engines.
A Sanding Block is a necessity for squaring fin edges, body tubes, launch lugs and nose
cone shoulders. You can't possibly sand the flat sides of fins (and keep them flat) using
sandpaper over your fingers.
If you don't own a sanding block, I suggest the Warner (Drywall) sanding block
(Warner Catalog # 436) available from Lowe's Building Supply store.
At Lowe's, the equivalent sanding block is now sold as "Finish Factor" #278865.
THE SANDING BLOCK
I have owned many blocks over the
years from homemade, X-Acto brand
and various hard rubber styles. The
Warner block is the best I've found
and is cheaper and more durable
than the X-Acto brand block.
The Warner block conveniently holds a 1/4 sheet of sandpaper. Fold a full-size, new
sandpaper sheet into quarters. Cut into four equal rectangular pieces using scissors.
Cutting sandpaper with scissors will also sharpen them! (Only fine grit sandpaper,
320 grit or finer should be cut with scissors.)
Unscrew the wing nut and hold the sand paper around the larger wedge of the block.
Center the upper half of the block, set over the inset bolt and tighten down the wing nut.
This locks the sandpaper into place. Don't over tighten the wing nut - over time it could
strip the bolt.
In addition to being a comfortable sanding block, the lower half of the block has a both
rounded and wedge shaped sides. Both sides come in handy for contour sanding.
I have found the only sandpaper I use in low power (balsa) rocket building is 400 grit.
This is the Extra Fine, black, "Wet /Dry" designated sandpaper. When using
sanding sealer or Fill N' Finish, anything rougher than 400 grit will sand through the
painted/treated surface down to the rough wood.
400 grit is the great all-around paper for most rocket construction. It will dress up
body tube ends, smooth nose cones, and sand Fill-N'-Finish easily.
In this article I am talking about Balsa nose cone and finned rockets. Anytime basswood or
plywood is used you will need to "step-up" to a rougher grade paper, 220 or 320 grits. Or,
for example, if you are shaping an airfoil into 1/4" balsa stock you'll want to start the rough
form with 220. Then, change to 320 and finish out with 400 grit.
#11 HOBBY STYLE KNIFE BLADES
The X-Acto #11 blade is the
"standard" for hobbyists.
Use a #11 blade in a #1 size
Buying new X-Acto brand blades in
hobby or craft stores can cost from
$.50 to $1.00 each!
Order your blades in bulk and
Don't bother buying a "chest" of assorted knife and blades. In the end you will use the #1
handle and #11 blade 90% of the time
Another way to save money is to use single edge razor blades when making
straight cuts, against a straight edge. The pointed X-Acto #11 blade is still best for
making circular cuts. You can't maneuver the flat single edge razor blade around a arc
Buy at least and 12", or longer
metal straight edge ruler. Try to
buy a straight edge with a cork
backing strip. The cork backing will
help keep the edge in place when
cutting straight lines. Buy a ruler
style straightedge with inch and
Many modeler's use a 18" (or shorter) piece of aluminum angle. You can even glue
a wooden ruler to the edge for measurement reference. The angle is a convenient trough
for marking fins lines on the body tube. It also protects your finger tips from being cut.
Don't use a 12" wooden ruler to cut out fins. You will soon cut into the ruler with your blade.
Even the wooden rulers with a metal edge aren't usable for very long. The metal strip
always comes loose or gets bent.
When holding the straightedge with your free hand, keep your fingertips back
and clear of the blade's cutting line!
For years, we all used the brown
(painter's) masking tape with mixed
results. The lines were never as clean
as I would have liked. Other times, the
tape was too sticky and could pull up
the underlying color.
Blue masking tape is better, but still
not perfect. It didn't pull off the base
color but there could still be a rough
line at the color separation.
The best masking tape (for paint
separation lines) is not a masking
tape at all. It's simply Scotch
Brand Magic Tape.
I would stay with the name brand Scotch Tape. A bargain brand may not stick as well. It
comes in the standard "Scotch" tape clear plastic dispenser. Look for a green plaid
Last year I was using the Scotch Brand "Removable" Tape. But after trying both, side by
side, I didn't notice any real difference in the final results. The Removable Tape , in the
Blue Plaid package, is not as sticky as won't pull off the base color paint. The edges of
the plastic tape are straighter and cleaner than any masking tape!
Using the clear tape, I have the best masking lines/paint separation lines ever!
I first saw this suggestion on the www.ApogeeRockets.com website. Check out
the Apogee Peak Of Flight back issues, - they're FREE! Apogee has a large
"database" for rocketry information, design and construction tips.
If your base surface isn't smooth (orange peel or glue blobs) you'll never get a
clean line no matter what type of tape you use for masking!
Using any tape for masking will give mixed results when used around curved surfaces or
in tight corners. It's tough to mask over the top of a nose cone or at the body tube/fin joint.
Take your time and insure the tape is adhering in all places being masked.
Tips and Techniques by Hans "Chris" Michielssen
I buy 100 (X-Acto clone) blades at a time from: www.modelexpo-online.com
I can get 100 blades for $16.99 or .17 each!
Continued on page 2 -
"THE BEST TOOLS", Part 2