Rust treatment remedy

[SpecialT]

Various light "orange" begins to show up on certain painted chrome moly tube fuselage parts around the plane. Some of the "orange" is down in crevices and cracks between welded parts and is not easily accessible. Whats the best practice for removing and treating these areas of potential corrosion and to keep the rust from growing before it takes off?

What about around the wing attach fittings, and gear bolts?

Has anyone used phosphoric acid to neutralize the rust? What kind of effect would it have if it got on the polyfiber?

[Mark Julicher]

Re: Rust treatment remedy

I'm not too sure about phosphoric acid affecting the fabric.
I would put Corrosion X on the affected area because it is designed to coat and stop rust and it will creep into the crevices. ACF 50 is also a good product for the task.

[PA1195]

Re: Rust treatment remedy

There's an AD on that wing strut fitting in the second picture. Also a Taylorcraft Service Bulletin that addresses the inspection method. I'd make sure it's not corroded internally and along the nearby frame tubing near the fitting and inside the cockpit. On mine I had it inspected then pumped the fitting full of Corrosion-X and coated the nearby tubing.

Gary

[SpecialT]

Re: Rust treatment remedy

Upon inspection my lower wing strut attachments have no internal corrosion. But interestingly they do not contain a drain hole like shown in the SB.

[3Dreaming]

Re: Rust treatment remedy

Depending on the modifications it may have been covered over with a metal patch. Swick changed the angle of the strut attach fitting, so it was inline with the strut. When they did this they weld a finger type patch over the fitting that wraps all the way around. If you don't change the angle the loads create a twisting motion on the longeron.