Radio Control: Pylon Racing
Bill Hager 706 Glen Haven Dr. Conroe, TX 77302
HIBERNATING?
For most of you, the winter months are a good time to rebuild your fleet of Pylon Racers. Don't forget to take proper care of your radio gear — don't just throw it in a corner. Now would be a good time to check all of the wiring, connectors, etc. Yes, take the radio out and go through it completely.
If it needs servicing that you can't do, send it back to the dealer (or whomever you use) for service. Don't wait till springtime when everyone else sends their radios in, too. You will not only get faster service, but you might—because the service people won't be rushed—get a better job.
Oh, yeah. Don't neglect your batteries. Always charge them up at least once a month. If you have one of the battery cyclers, use it. I've seen my share of people come out in the spring with new planes, only to crash them due to bad batteries.
For those of you who build with fiberglass, here is a helpful article on molded fiberglass fuselage finishing techniques written by my good friend, Art Arro.
Fiberglass Fuselage Finishing (Art Arro)
Just about every Pylon Racer (except maybe the Quickie fliers) employs molded fiberglass parts for fuselages, cowls, and wheel pants. Pinholes in the surface are the bane of finishing these parts, and some are evident on even the best of glass work. Over the years I've tried many procedures to get rid of pinholes, but I am finally satisfied with the following technique. Credit is due Bob Violett, now a fan-jet jockey, formerly a Pylon Racer. I am merely disseminating his technique.
- Thoroughly wash all molded fiberglass parts with warm water and a good dishwashing detergent to remove any traces of mold-release agent which may cause poor paint adhesion later on. When the parts are clean, hang them up to dry.
- When dry, inspect the parts for pinholes, resin-dry areas, and seam imperfections. Circle these with a soft lead pencil.
- Fill resin-dry areas with a wet mixture of microballoons and a compatible resin. When the patch is completely cured, block-sand these areas to blend with the surrounding surface. Try to support the inside of the fuselage, if possible, during this process. Limit your sanding to the affected areas and use masking tape to shield areas which are already acceptable to prevent scratches and further raising of pinholes due to excessive sanding.
- Use a similar treatment on seam imperfections. Masking tape works well here.
- When you're satisfied that these flaws are rectified, rub down the entire part with a medium-grade scuff pad. These pads are made by 3-M and are available in automotive-finish and hardware stores. They are a modern-day replacement for steel wool.
- Sand and scuff the entire fuselage before installing the firewall, holddowns, etc., to prevent these parts from showing through.
- Complete the entire model until it is ready for primer and paint. Check for any resin drips and fingerprints, and remove them by scraping and/or careful sanding.
- To eliminate pinholes, apply Bob Violett's Pinhole Filler using a clean paper towel. This product is made specifically for filling pinholes; apply it like shoe polish in a circular motion to completely fill all pinholes. Allow it to dry to a haze (an hour or two), and wipe off any remaining filler with a clean paper towel.
- Spray on a heavy coat of K&B Superpoxy primer (mixed with primer catalyst), and inspect the part to be sure there are no voids or defects. Fill these with a mix of microballoons (Prather Miracle-type) and Superpoxy primer, daubed on with a small brush or stick. Note that the filler is applied while the primer is still in the curing stage.
- Allow the fiberglass parts to cure overnight or longer before sanding. Use 220-grit sandpaper bonded to a block, and try to remove as much of the primer as possible. Wear a dust mask if you're dry-sanding or appropriate clothing if wet-sanding. This is a messy job!
- When finished, the fuselage (or your molded part) should have an overall light haze of primer with some solid white areas filling the low spots. This is for minimum weight build-up.
- Mix up a blend of K&B primer and white paint (50/50), and add the appropriate catalyst. Spray this mix on as a foundation base coat, and sand with 320-grit when it's cured.
- Clean parts with alcohol (methanol), and you're ready to apply color.
I've tried this technique finishing a Prather QM and was very pleased with the results.
The pinhole filler is available from Bob Violett Models, 1373 Citrus Road, Winter Springs, FL 32708. The price is $4.95 for a jar, which should be enough to handle several QM and/or Formula 1/FAI molded glass parts. Give it a try, and I know you'll be satisfied.
Once again, my thanks to Art Arro for sharing this with us. If any of you have some helpful hints, send them in and I'll pass them on.
See you next month.
Transcribed from original scans by AI. Minor OCR errors may remain.
