Corrosion within the laminate

[Charles]

Sure, it's done all the time and would add negligible weight. Plate a few microns of nickel on the copper and plate another few microns of gold over the nickel. Nickel is there to prevent copper from diffusing into gold over time. If you do the plating after all holes are drilled and all the machining is done, it would make it virtually corrosion-proof as long as the plating is not abraded or damaged in any way. That's how gold-plated electrical connectors are made.

A little late to do that on our planes though, now that the raw copper is embedded in the laminate...

[Colin]

I have a 2005 DA40 and I can see very slight signs this is happening. I have to take the wings off in June, so I will probably be faced with this repair.

Very sobering.

[Nigel]

I have a 2005 DA40 and I can see very slight signs this is happening. I have to take the wings off in June, so I will probably be faced with this repair.

Very sobering.

That's unfortunate Colin. I've seen no hint of it yet. I wonder if it's related to exposure to sea air. How far are you from the coast? My wife and I made our first trip from Toronto to the Bahamas in March and in an abundance of caution I re-applied a coat of LPS 3 to all exposed metal parts before leaving.

[Gary]

I have a 2005 DA40 and I can see very slight signs this is happening. I have to take the wings off in June, so I will probably be faced with this repair.

Very sobering.

I don't think it needs to be fixed if it is slight corrosion but the repair might be a little less involved if it is done early.

[Colin]

I am two miles from the shore. Probably a little closer when I am at the airport. And it is outdoors and there is a sea breeze.

But reading everything here two things come through:

a. It is not a structural item, it has to do with grounding and the lightning protection. I bet that piece can get fairly lace-like and still conduct a few electrons.

b. This is a design error and it should have been covered with anti-corrosion goo. The idea that you have to rebuild the end of the wing every ten years seems a little nutty on an otherwise impervious plane.

I think that I will be doing a fairly cosmetic cleanup of the situation when I have the wings off. (My brother said it was a good excuse to sell the plane this month and move up to a DA42. He has an inflated sense of my cash flow since he is an eternal student.)

[Paul]

Colin, nice to see you posting again. Apologies for the total thread drift but I need to drop someone off at LAX next week and then leave my plane for two nights. Can you recommend the most convenient airport?

[Colin]

I would use KHHR (Hawthorne). I bet the FBO there will arrange a rental car and everything.

So will Atlantic at KSMO (Santa Monica) my home base, and it depends on where you are going to be for those two nights, but I bet KSMO is just a little more expensive (I haven't actually checked that, I'm guessing).

[Lance Murray]

Hawthorne gets a bit pricey. Call them first.

[Robin]

My aircraft is now located at Point Cook, right on the coast line, I asked my LAME - licenced aircraft maintenance engineer for his thoughts on corrosion proofing

His reply....

Unfortunately diamond did not have any corrosion prevention program, however i would suggest the following: I was thinking that the Ardrox AV8 (water repellant) would work on all the exposed material such as the cables, screws etc.

As for the screws mentioned in the link( THIS THREAD), it may be adviceable to remove the screws then apply Duralac/ Mastanox and then put them back in.

Cheers


Robin

[Charles]

Better late than never.

The corrosion problem on my plane became impossible to ignore despite the fact that I keep it in a heated hangar so I decided to do something about it. After shopping around to find the best place to do this tricky work of grinding the wing, replacing the bonding strip, and painting, I opted for XU Aviation in London who quoted a much lower price than any shop in my area and boy was I happy with the results.

This ended up being a big annual in which many things were fixed. Among others:

- Corrosion problem above including full wing and wing root paint
- New painted wing walks per OSB
- Fix of the wing root trailing edge crack
- Paint flaking off the leading edge of both wings
- Arizona baffle (I have an older 40)
- Touch up of some cowling fire paint
- Fix of a severe rear door hinge crack
- Replacement of corroded flap and aileron hinges
- Misc squawks from annual
- MLG and NLG struts repainted
- OSB for wing spar reinforcement

My plane looks and feels like brand new! The guys at XU are exceptional and they have easy access to tools and engineering info at Diamond next door. For you guys in the US, with the current exchange rate, I'd have all my work done by those guys if I were you. It was a 3 hour flight for me to get there, and I had to bring the plane to them twice, but it was well worth the trip and the hassle of flying back home in the company jet to leave the plane to them.