Control Line: Aerobatics

Control Line: Aerobatics

By Wynn Paul

Announcements

• 1981 Nationals near San Antonio, TX — volunteers needed.
• Event Director: Bill Howe

7769 Mary Lou Way, Sacramento, CA 95832 (916) 421-8866

• Roles needed: judges, recorders, scorers, pit bosses, pull testers, site preparation, etc.
• An Assistant Event Director is also needed. If you’ve asked what you can do for PAMPA, volunteer to work the Nationals — call or write Bill Howe.

• Foam wings from John Poynter
• John is still producing foam wings, although more slowly due to a full-time job.
• Contact: John Poynter

10261 Janice Lynn, Cypress, CA 90630 (For sizes and prices, write to John.)

Recent Results

• Les McDonald added the King Orange title to his World and National Championships (contest attracted 20 entries, Jacksonville, FL, last weekend in December).
• Frank McMillan finished second to Les in PAMPA Expert.
• Paul Fewell won Advanced; Jim Mitchell was second.
• Gene Latham won Senior-Open Novice.
• Scott Baker won Junior Novice.
• Mike Mustain won the Profile Stunt event.

Finishing Technique: Gene Martine’s Method

Gene Martine (Jacksonville, FL), winner of the 1980 PAMPA Concours d’Elegance, uses a meticulous, multi-stage finishing process. The key is preparation and patience.

1. Preparation and initial seal

• Assemble the plane in the bare-wood state without fillets.
• Mix Hobbypoxy (Gene used Hobbypoxy No. 2 glue on his 1980 plane but prefers the clear Hobbypoxy for later work). Let the mixture cure ~45 minutes, then brush a coat of Hobbypoxy clear on the bare wood as a temporary seal to keep oils and dirt off.

1. Initial clear coats (brushed)

• Brush on 100% clear (unthinned) dope with even strokes to avoid buildup. Gene prefers Aero Gloss clear at this stage for compatibility with Hobbypoxy.
• Apply a second brushed coat of 100% Aero Gloss clear.

1. Covering with paper (silkspan)

• Ensure airframe surfaces are smooth and true; use vinyl spackling compound (hardware store) for nicks and dings.
• Lay paper up to joints; apply the paper wet with water.
• Where overlaps occur (e.g., wing panels), rip the paper rather than cut so edges stay down. Overlaps about 1/4 in.
• While paper is wet, brush Aero Gloss thinned 50/50 around edges.
• After paper dries, brush another coat of 50/50 Aero Gloss clear, sand lightly with No. 220, then brush a coat of 100% Aero Gloss clear.

1. Fillets

• Apply fillets using Epoxolite over the paper (fillets are applied after covering).
• Lightly sand the whole plane with No. 220.
• On the fillets only, apply three brushed coats of 100% Aero Gloss clear, allowing at least eight hours drying time between coats. Avoid touching the fillets while curing.

1. Build-up of clear coats (brushed)

• Brush two more coats of 100% Aero Gloss clear, sanding very lightly with No. 220 between coats.
• Assess surfaces with reflected light; shiny spots indicate paper is filling well.

1. Transition to spraying

• Decide whether to continue with Aero Gloss or switch to Sig (or other) paint. Remaining coats will be sprayed.
• Spray two coats of either Sig or Aero Gloss clear.
• Spray one or more coats of filler (traditional mix ratios around 1/6th to 1/8th). You may need two coats of filler.
• Lightly sand filler coats (this can be time-consuming — expect long sanding sessions).
• Spray two complete coats of clear.

1. Silver base and repairs

• Spray the first coat of silver; imperfections will be highly visible.
• To fill small dings and dents over the silver, Gene uses Nitro-Span Red Putty No. 900 (auto body supplier) applied over the silver — he reports it works well.
• Spray a second coat of silver and lightly sand dry. The surface should now be perfect.
• Spray a wet coat of clear (slightly heavy) to prepare for the color base.

1. Color base, trim, and sealing

• Use as few coats of color as will achieve coverage.
• Spray a light coat of clear so masking tape won’t pull up the base coat.
• Apply trim paint, then seal the trim with one or two sprayed coats of clear.
• Remove most of the paint edges carefully: use a wet clean rag with Ajax, Comet, or Soft-Scrub to rub most edges away. For finer control, use No. 600 wet sandpaper.
• Clean thoroughly with alcohol, spray one more coat of clear, then wet sand with No. 400.
• Apply any pinstriping or Radiograph pen work, then one more light coat of clear.

1. Final clear coats and rubbing

• Spray 3–4 clear coats in one day (example schedule: 8:00 a.m., 11:00 a.m., 3:00 p.m., 6:00 p.m.). Let the plane sit overnight.
• Next day, lightly wet-sand with “old” No. 400 paper (used paper).
• Apply another series of 3–4 clear coats; let sit overnight.
• Apply one more series of 3–4 clear coats, then wet-sand with No. 400.
• If the Nationals are not imminent, let the plane cure two weeks, then use No. 600 for wet-sanding before final rubbing.
• Rubbing sequence: start with fine cutting compound, then white compound, then Turtle Wax liquid rubbing compound.
• Optionally apply a very light coat of wax.

Tips and Notes

• The process is long and tedious but necessary for a fast, deep polish.
• Work slowly; meticulous preparation and sanding between coats are crucial.
• Avoid touching surfaces during critical curing periods to prevent oils from fingerprints causing flaws.
• Gene prefers to brush early coats for control, then switch to spraying for finish uniformity.

Contacts for More Information

• Bill Howe (Nationals):
• John Poynter (foam wings):

10261 Janice Lynn, Cypress, CA 90630

• For information on stunt or PAMPA:

Wynn Paul 1640 Maywick Dr., Lexington, KY 40504

• Gene Martine (finishing techniques):

Jacksonville, FL

Transcribed from original scans by AI. Minor OCR errors may remain.