Protecting unprimed Alclad

[kritsher]

I posted this question in the -12 forum, but I thought I'd ask the larger RV community:

For those who are not priming the interior allclad parts, what ARE you doing to protect those parts as you work and to remove dirt and fingerprints before you button up the assemblies? It's inevitable that fingerprints and sweat will get on parts as you work on them, and it's my understanding that the oils and acids from those fluids can promote corrosion. I'm curious to know what people who aren't priming are doing to keep those surfaces as clean as possible . What are the best practices? What are the best products for removing fingerprints and sweat from unprimed parts? I've been wiping down with rubbing alcohol. Is there a better technique?

Thanks for your thoughts.

[dhall_polo]

coleman camp fuel.

[flion]

Mineral spirits are also a good cleaner. I leave the plastic on as long as possible. Once the plastic is off, I try to be as careful as possible of the cladding and wipe mating surfaces before final assembly. I've got lots of old blankets to cover areas that need protection while I work over them. Once I get to the cabin area I won't need to be so diligent because the interior will be finished.

There are, in any case, some practical limitations to how clean you can keep things. Inevitably there are places where you have to drill or file after assembly and chips are impossible to control. Enclosed spaces will gather a light dust film and will be difficult to impossible to reach and clean. And, of course, cladding does not exist on the edges of the material. Despite this, aluminum alloy is resistant to corrosion and your aircraft will probably be just fine.

To that end, dissimilar metals should always have one or both mating surfaces primed. Drainage pathways should be provided and the aircraft should be protected as much as possible from the elements and kept as clean as possible. That said, don't sweat it too much. Aside from all the anecdotal evidence of aircraft that have lasted years without priming, I can also point you to our old friend, the aluminum fishing boat. The one I used in my teenage years had scraped bottom enough that the paint and coating were long gone, lived in a wet outdoor environment (Mississippi), was often muddy, oily from the trolling motor, etc. and is still being used by a cousin who bought it for his kids when we moved away from the South.

Corrosion is insidious and must be looked for and dealt with but it seems to me that it most often appears when an aircraft sits unused (and first in the remote, uninspected recesses). But a working airframe does not seem as prone to start corroding.