Page 12 - Volume 11 Number 12

Prepping the areas on the aluminum skin that were less than perfect, by adding filler and then smoothing it out by sanding.
of us old-timers keep referring to it as that. Alodining is another anti-corrosion option. Some shops offer alodining as a “pre-treatment” before the primer.
The world of aircraft paint systems has advanced dramatically from the old days of zinc chromate. Now there are pre-treatments, multi-step primer systems, adhesion enhancers, etc., and we haven’t even discussed paint yet.
Surface preparation is a crucial aspect of any paint job – aircraft painting is certainly no exception. Before or during priming, minor dents or skin distortions are smoothed out with filler and sanded. Although power sanders are often employed, I’m a stickler for sanding by hand whenever possible. The use of power sanders on an airplane make me cringe.
I’ll never forget the King Air that came to my shop for a routine phase inspection. As the owner pointed out his new N-number, I happened to notice some button- head rivets missing. I looked a little closer and saw that every rivet in the N-number area was shorn down flush with the skin! Apparently, the shop that performed the work used a power sander when they shouldn’t have. Needless to say, it was an expensive squawk to remedy. Every rivet had to be replaced and each button-head meticulously re-touched with paint. King Airs are loaded with button-head rivets.
The aircraft after it has been primed and ready for the paint process.
Applying the base coat is nearly complete; Matterhorn White is a frequent choice. The wing lockers, cowlings, panels and grates are removed and painted separately.
Control Surfaces and Flaps
The ailerons, elevators and rudder are removed and painted separately. They are re-balanced in accordance with the maintenance manual, then reinstalled on the aircraft. Failure to balance a control surface per the manual can result in flutter during flight. If the flutter is extreme, the whole thing can rip off.
Flaps are another story. Some paint shops remove them, others do not. I feel strongly that flaps should be removed for paint. When they are left on the wing, stripper can seep into areas that are impossible to clean. Where stripper sits, corrosion develops. In this case, the flap bearings and washers are at risk; and when they go bad, the flap tracks are the next to go. Flap tracks are nothing to mess with. If I had a King Air being painted, I’d insist the flaps be removed.
Post-paint Inspection
Don’t be in a hurry to pick up your King Air from the paint shop. Take at least a half-day to look closely at everything. Check for drips, fish eye, gaps and overspray. Minor blemishes and flaws can be remedied, but hopefully there are no such issues. If possible, bring your mechanic along to verify the control surfaces have been balanced per the manual. It behooves you to have someone double check their figures.
10 • KING AIR MAGAZINE
DECEMBER 2017