Pitted Aluminum

Joe & Jenny

Joe & Jenny

Newbie
Hey Guys,

Not sure if I am posting in the proper forum but for some reason this forum is all I have access to. Windows 10 just updated and that usually reeks havoc on my machine for a week or two. Anyways, the point of my post...Pitting in surface of my Campinn 560. I am the 2nd owner of my Campinn and my wife and I love it. Keeping it clean is awfully tough though especially since we are located on Long Island and surrounded by salt. We have owned our camper for just a little more than a year and when we bought it, it wasn't cheap. We want it to last as long as it can so I am trying to keep it clean with a good polish and such, however, this year I am noticing some significant pitting in the skin and I am worried. How do I go about getting rid of the pitting. It isn't super heavy but it is noticeable. How can I prevent more pitting and what can I seal the camper with to prevent future pitting? Is there a specific cleaner that I can use? Do any of you use Vinegar? Does it need to be acid washed? Any help would be much appreciated. Thanks, Joe
 
It is not anodized, it's milled aluminum. I think anodized aluminum would be an option to be considered, don't know what kind of cost it adds. Some tear drop manufacturers do use anodized and the ones I have seen look very sharp and seem like they would hold up better to the elements over time.
 
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It can be a lot of work to keep them looking like new, and very understandable why so many prefer the natural patina they develop, but if you are determined to get it looking closer to new again, here are some things I have done that have worked for me, but your mileage may vary.

NAPA makes an aluminum cleaner that is acid based, and pretty aggressive, and will clean oxidation off the aluminum, but it can be tricky to use. When I used it, I did it on a calm cloudy day so it wouldn't dry too quickly, using a garden style pump sprayer, from the bottom up (otherwise it will streak the aluminum), doing one side at a time with a soft sponge working with the grain. Then it has to be rinsed off thoroughly before it dries to avoid streaking as well, but along with the oxidation, it did help remove some minor salt air pitting that the previous owner had picked up on a trip to FL .

If you are wondering, the grain runs front to back on the TD sides, and side to side on the front, top, and hatch. Once it was well cleaned, thoroughly rinsed, and dried, I used some 3M Marine Ultra Performance Paste wax to help protect the bare aluminum. That was several years ago, and since then I have also used Mothers Aluminum Polish to remove oxidation, which isn't as aggressive as the NAPA cleaner, but you still have to be careful to lightly work it with the grain if you don't want to end up a mirror finish. I use a spray detailer like Wizards Mist N Shine for removing finger prints, bug splatter etc. after each trip.

Just try to remember no matter what you are putting on it, or even just dusting or washing, always try to work with the grain. Aluminum is soft, and if there is any grit in your washing /dusting/cleaning sponge or cloth it will leave scratches, which will be much more noticeable if they are done in a circular motion than if they are with the grain of the mill finish already on the aluminum.

Good luck!:)
 
I'm just not sure what "pitting" means. I have one little streak where salt stayed on the campinn after a winter trip and wash (from a drip.) That streak from salt doesn't seem to want to come off.

We've been trying to develop the natural oxidized patina. I don't know if that would work for you because of the salt.

We try not to touch the aluminum, and if we do, we gently clean the spot with rubbing alcohol. We power wash after a long trip, but otherwise do nothing. The objective is a patina.

I wonder if this would work for you? I am uncertain because I'm not sure what you mean by pitting.
 
It's corrosion of the aluminum, similar to rust caused by salt on steel except on aluminum it will look whitish instead of the rust color you see on ferrous metals, but like steel it will be a little roughened in that area. The pitting is where the corrosion has undermined the flat surface of the metal, so that it has small pockets/ pits in it's otherwise flat surface. When it first starts it will appear mainly just whitish, and can be more successfully addressed at that point when it hasn't undermined the surface too much yet. The longer it's left the deeper the undermining/pitting will be, and the harder to resolve without it looking different than the surrounding area. Some people think that aluminum won't rust, but it does, it just looks different than ferrous metal when it does. The patina is an oxidized layer of aluminum that is somewhat like the seasoning that the cast iron cookware folk strive for to protect of the underlying metal from rusting. It works fairly well if it is developed enough before exposure to corrosive things, but salt still needs to be washed off relatively soon after exposure, just like you wouldn't store your cast iron cookware after having salty water in it without rinsing it out thoroughly, and drying it off. Hope that helps.
 
Thanks so much.

That's what is on my door from a drip! It was a January trip home and I took the trailer to a car wash and washed it carefully, but the drip came down from the window later. Would you use the NAPA cleaner on the drip rivulet, or would you leave it be? will the drip continue to "rust?"

I've washed it several times since. Interestingly, we were just at the coast and in Astoria, stopped at a car wash to get salt off. There was a "Salt Remover" setting on the car wash that I used first.
 
We have a streak beneath one of our door windows as well, which was the result of inadequate rinsing after using the NAPA cleaner, and having some of it run down from the window seal after the rinsing was done. A reapplication to that area helped reduce, but not eliminate the streak.
Your corroded area sounds like it has stabilized from your washing it, and removing whatever caused it. That area has probably developed a new protective layer of oxidation, so probably is fine unless exposed again to a corrosive element.

So if you do try using the NAPA cleaner to spot clean that area, it will look different than the surrounding area because the patina will only be removed where you use the cleaner. It would probably eventually even out again as a new patina develops, but may always look a little different if the patina on the surrounding area continues to mature at the same time. So it's probably not really practical to spot clean. It would need to be cleaned by at least a section (like one whole side) at a time, if not the whole TD, but can't say for sure since I haven't done it that way. I did the whole TD.
 
You are very welcome. I am far from being a an expert, but have learned a little along the way from both my own and others experiences, and am happy to share what I can.

A friend of mine built his own airplane, which has aluminum wings and control surfaces (ailerons, flaps, rudder). He liked the bright natural aluminum finish, so left his aluminum surfaces unfinished. He was also my mentor as I built mine, and as time went on I learned from him what a big job it was to keep those surfaces looking nice. He ended up letting them develop a "patina".

When I got to that point in my building process, I decided to apply a conversion coating (alodine) to all the aluminum surfaces, and then paint them, which was no small task either, but 11 years later and after 750 hrs of flying, those surfaces still look like new, and require almost no maintenance. I applied 3M clear paint protector film to all the leading edge surfaces to protect those high wear areas from sand, bug, and water wear, and it has kept those high wear areas looking like new as well, and will undoubtedly extend the time between paint jobs by a huge margin. I did leave the wing struts natural aluminum, but do need to use the Mothers Aluminum Polish on them regularly.
 

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This is some of the corrosion that was on the Time Capsule when I picked it up. It had sat 1/4 mile from the Pacific Ocean for 5 years without being washed or waxed. It had a cover that was pretty much disintegrated and went straight to the trash. I've started working on shining it up, but still have about 1/4 of it left to do. It is complicated because of the large decals and some brass accessories. The roof was also heavily scratched from having the ray gun and wind turbine set on top and slide around.
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Looks like you have your work cut out for you, but at least it looks like you don't have the stainless bumper to have to work around.:)You'll have to post some before and after pics.
Just remember it's a labor of love.;)
 
I have the bumper - 6 bolts hold that on. The bumper brackets were getting rusty, so off they came to get cleaned up and painted. The leveling jacks were more rust than paint - to hard to clean and paint, so new ones installed. Here are picts of the back with all the hardware removed, mostly sanded (only way to remove deep pits) and buffed and put back together. On the right side of the before pict - I did some polishing which removed the oxidation, but not the pitting.
 

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