Painting R-390A Front Panels

An EXCELLENT paint resource can be found here:

http://www.r-390a.net/faq-paint.htm

Front Panel

Part 1:

Remove all hardware from the front panel

Cover back of front panel with tape (to protect any paint or lettering on the back)

Spray Aircraft Paint Remover over the front surface

After a few minutes, begin removing paint with a plastic scraper and paper towels

Use a brass bristle brush to remove paint from engraved lettering

After all paint is removed, sand with medium sandpaper (150 grit)

Finish sand with fine sandpaper (400 or 600 grit)

DO NOT use steel wool

Remove tape from rear surface of the front panel

Acid-etch aluminum with Alumiprep

Prop panels up into a semi-vertical position to spray

Overspray "lightly" with a zinc oxide or zinc chromate based primer, found mostly in marine or aviation supply houses

Sand lightly with 1500 cloth

Part 2:

2A: Spray Can Method

Spray lightly with two coats of Dark Machine Gray (Rustoleum #7857), watching the sheen during the second coat until evenly finished and allowing 30 minutes to 1 hour between coats.  PPG #55-307, "Battleship Gray", and Plastikote # 1105, "Medium Gray" are also recommended as good matches.  For black panels, use Rustoleum Semi-gloss black.

Insert panel into an oven set at 150 degrees F immediately after applying the second coat

Let bake for approximately two hours

Remove and let cure for about 48 hours

2B: Paint Sprayer Method (MUCH better!)

Go by your favorite paint store, and get them to mix your favorite shade of gray (or color match your an existing panel), using oil-based semi-gloss (or satin) base.  I have been pleased with Benjamin Moore Satin Impervo.  Their best color for the panel is called a Smoke Gray.

After shaking well, mix your paint with thinner (mineral spirits) by 30% to 50%!  Yes, I KNOW this looks thin.  Do it anyway.

Set your sprayer on the finest, lightest mist you can.  Test with a piece of white paper.  I use about 40 psi pressure and a very fine mist.

Spray very light coats, about 5 minutes apart.  It should be the 3rd or 4th coat before you get complete coverage of the underlying primer.  Do NOT spray on heavily, as it will run easily since you thinned it so much.

Spray about 8 to 10 coats total.  This has taken you about an hour. 

You can speed drying by Inserting panel into an oven set at 150 degrees F immediately after applying the last coat, one to two hours

After fully dry, bake at about 200 degrees for at least two hours.  The paint may begin to "stink" at this point, which is normal

Remove and let cure for about 48 hours

Part 3:

Final Preparation

Polish the panel with rubbing compound (liquid type for removing swirl marks during automotive refinishing)

Warm the panel in the oven prior to lettering with a paint stick (about 120 degrees for 2 or 3 minutes)

Apply paint to panel lettering by smearing paint lightly and gently over the engraved letters

Remove excess paint stick with a diaper or soft cotton cloth about 1 to 2 minutes after application

Reapply paint as necessary if cloth creates any voids

Rub entire panel briskly and lightly to polish the panel and remove any "chalky" looking patches around the lettering.

Knobs

Knobs and meter covers and dial covers are done similarly, with a black (gloss or semi-gloss) paint.  Rustoleum #7777 "Satin Black", Krylon #1613, "Semi-Flat Black", and Krylon Epoxy #EP705 "Gloss Black" are possible choices.

For a nice trick to painting the knobs, take a look at Chuck Rippel's R-390A video.

Checkout The Quest Online to see where I now spend much of my time.  God Bless!

© 2005 by Walter Wilson, KK4DF.  All information is offered for non-commercial use without warranty, expressed or implied.