Radio Control: Pylon Racing
Author
Bill Hager 4 Holly Springs Dr. Conroe, TX 77302
Kits and Suppliers
- Small Creations — Formula One kits, Midget Mustang, Estrellita; 502 Cherry Lane, Southlake, TX 76092. Tel. 817-481-6456.
- Samurai Kaze — Formula One kit; 16016 Ave. 288, Visalia, CA 93277. Tel. 209-625-0325 (Gary Hoover).
- California Speed Pros — Formula One racer kits: Cosmic Wind, Shark, Long LA1, Midget Mustang, Denight Special, Estrellita, Larson T-Tail Quickie; 26612 LaTunas Dr., Mission Viejo, CA 92692. Tel. 714-365-1155 (Lyle Larson).
- Jim Katz Models — Poleduster Sport Pylon Racer, Tiger Moth, Quarter Midget; 308 Blackthorn Lane, Charlotte, NC 28209. Tel. 704-523-4420.
- Greg Doe — Kingcobra Quarter Midget Kit, P-39, P-63; 407 Pony Drive, Smyrna, TN 37167. Tel. 615-459-6845.
- Barry's Model Products — QM Polecat, New Q-500 T-Tail, Q-500 Sport; 1056 Grizzly Court, Apopka, FL 32712. Tel. 407-886-1949.
- Ritch's Hobbies — Texas Outlaw Q-500; 40104 Lark Lane, Houston, TX 77025. Tel. 713-661-5458 (Randy Ritch).
This just in: aluminum liners will be available next year for the Nelson engines.
After you've built your racer — Finishing tips (Gary McPike)
With Formula One racing, the finish you get on your airplane is very important — not just because the best-looking plane takes off first, but because a well-finished plane goes faster and even flies better. Gary McPike has shared his finishing technique:
I was going to start with the primer — you know: sand, paint color, sand, paint trim, sand, paint clear, fly — but to get a good paint job you must go back several steps before you get to the primer. You can't get a good paint job if what you are painting is not properly prepared for it.
I'll start at the point where the whole plane is finished and the fill coat of resin has been brushed on all the wood parts. Sanding must always be done with a sanding block — and not with 80-grit! I recommend sanding everything wet for two reasons: first, you can sand with finer paper and sand faster (break the gloss and knock off the chunks and runs with 180-grit wet, then finish and smooth with 220 or 240-grit wet); second, you can tell where you go through the wood. It's faster to re-coat a few spots now than to shoot an additional coat of primer when you're trying to save time and weight later on.
At this point, you do not have your control surfaces hinged or installed; some like to paint them separately, some install and paint them and the plane as a unit. Some even bolt the wing to the fuselage and paint so no primer and paint are on the center of the wing. I'll make no recommendation on that one, but I will recommend that you hinge and install all the control surfaces before you paint your plane. You will find that any irregularities in your hinge lines or bulges in the wood can be corrected faster now than later.
Now go over your plane with a final filler. Hobbypoxy Stuff or 3M Acrylic Spot Filler (light green) both work well. Fill everything that looks like an air bubble in the epoxy parts. Put a light coat on the tail fillets and around the canopy fillet and landing gear fillets. Fill using your finger — not a stick or putty knife. You'll get imperfections filled better and with less filler that way. It also cleans off your hands with acetone.
Now you have a plane that looks like it has measles. Let the filler set overnight — or longer if you have the time. Sand the spot filler off with a sanding block using 240 wet paper and water with a few drops of dishwashing detergent in it. The detergent will help keep the paper from getting clogged with the fine powder the filler produces as you sand. Be careful not to sand through the resin on the tail and wing; if you do, spot them again.
If you are running short on time at this point, you can speed up the resin by using a MonoKote heat gun or a hair dryer to heat up the resin. It will cure in a matter of minutes. But be careful not to get it too hot, or you might cause warps in the wood or melt the foam under the wood in the wing!
Now you should have the whole plane sanded and the minor nooks and crannies filled and sanded flat and smooth. This is the most critical part of painting a model plane — the preparation. If your plane is smooth, the paint goes on smooth; if not, the paint will show all the imperfections under it.
A good light paint job is only about .012 inches thick. So you do not have much to play with in painting. I'm not going to get into painting jigs, but you should have some way of holding the parts of a plane as you paint them.
Mask off the canopy. I recommend Scotch 33 electrical tape. It's flexible and leaves a good clean paint line. Clean the plane with alcohol — not acetone. Rubbing alcohol can be found in any drug store. Methanol works better since it does not leave any residue. Clean the parts at least twice. Don't forget the hinge lines inside the elevators and under the fuselage. Use about four paper towels for the wing and about the same for the fuselage. After the plane and its parts are clean, they're ready for primer.
I recommend K&B primer. It's easy to find at a hobby store and is fuel-proof. The first coat of primer should be thinned at least 50%. This will fill the pinholes. Shoot the primer at 25 to 30 pounds of pressure. A light coat will do — don't put on a heavy coat.
After you've sprayed this on, go over the surface with your finger and work the primer into the larger pinholes that were not filled when spraying. If you can't get all the pinholes, don't worry — we'll get to them later. Let the first coat tack for about 20 minutes.
The second coat should be shot at about 35 pounds of air. I add talcum powder to the primer to help it build up better and sand faster. The second coat should be as heavy as you can get it on the plane. You'll probably get some small runs. Don't worry — you are going to sand it all off anyway.
You should have shot most of the mixed primer onto the plane. Take what is left and put it in your freezer. It will keep about two weeks and can be used later if you get any dings in the plane.
Let the primer dry indoors out of the sun for at least 36 hours. Now get out your trusty sanding block, water, and dishwashing detergent and sand it all off. If you are planning on painting with K&B Superpoxy, use 400-grit and go to 600 or 800 wet paper. If using polyurethane paints use up to 1,000-grit wet. Fine sand for the color coats.
If you are going to use any of the acrylic or urethane paints, use 360 paper (available in auto paint stores) for sanding primer before color coats.
Now you are ready for the color coats. The first color coat should be light and shot at 30 pounds. Don't try to build up color with several heavy coats. Let each coat dry and sand lightly with 800 or 1,000 grit if necessary. Use an adhesion promoter when painting with polyurethane finishes.
For decals, use dry solvent under the decal and dry solvent over it. This will help the decal to conform and seat down into the paint. Seal the edges of the decals with a light coat of clear.
For clear coats, use at least two coats — three are better — of a gloss clear, sanding between coats with 1,200-grit if necessary. Use a final polish.
Now get back to the control surfaces. Our torsion hinge method worked well, but you will have to get the gaps perfect. Some use microballoons to help smooth the hinge lines.
Weight is a pylon racer's worst enemy. Try to save ounces where you can without sacrificing strength. Ballast should be used only when necessary. Try to move components to get the proper balance.
Sand as much of the primer off as you can. The primed airplane should only pick up 1/4 to 1 1/2 oz. of weight between finished-ready-paint and primer-sanded-ready-for-color. This will make the difference between a light and very light airplane. Believe me.
Some builders go back over the airplane with a very light coat of primer after the first heavy coat has been sanded off, just to make sure that all of the pinholes and irregularities have been filled and the plane is smooth. You can do this if you want to; I don't, because the color paint I use is satin and has filler in it. Whether you choose to stop at the heavy coat or put on an insurance coat, there's one thing you must do: sand off as much primer as you can!
When you are finished sanding, the whole airplane should look like a "meadow in early spring," with small patches of white and large patches of resin and epoxy.
(More on finishing your Pylon Racer next month.) — Bill Hager
Transcribed from original scans by AI. Minor OCR errors may remain.
