What is this alum finish, and how should I clean/deoxidize?

[qft]

Hey folks -

I bought this handmade teardrop. I'm trying to figure out what kind of finish this is, how to easily get it cleaned up, and protected. The wheels and toolbox are a sprayjob red and I'd like to avoid damaging that too.

- What kind of aluminum finish is this? Brushed?
- I hear truck washes have an acid wash. Can I go to one of those, and follow up with turtle wax? Would that take care of the oxidation? Would I need to protect the toolbox/wheels with a plastic tarp or something?
- Ideally I'm looking for something quick, inexpensive, and to avoid removing the toolbox

Picture of the teardrop

Closeup of the finish/oxidation

I've used the search for other threads, but I'm uncertain of the best way to treat this particular finish and didn't want to get it wrong.

Thanks a lot!

[capnTelescope]

That looks to me like a "mill finish." I have the same question as you,

how to easily get it cleaned up, and protected

I've got road grime and sweat stains to take care of.

[ae6black]

To be perfectly honest after wet sanding my with emery cloth and waxing it (It was pretty bad from being under a tarp for the winter) and still having the oxidation coming back I am just letting mine go natural. I don't color my hair or beard so why would I try to keep my camper finish from aging. Besides keeping the thing that shiny would be a whole lot more work than trying to color what little hair I have left. I built the thing to camp in so I am just going to enjoy it as is.

Art

[razorback]

Do not under any circumstances go to a commercial truck wash. Their acids will have one or two or three different acids which will damage your aluminum.
If their acids contain hydrochloric, hydroflouric, sulfuric, do not use on your TD. From your photo I cannot tell if your original aluminum came with a protective finish. If it did those acids will remove it in a hurry which will cause rapid oxidation to reoccur.
My TD does not have aluminum on the exterior. If your trailer were my trailer I would take 1 cup of vinegar in a clean milk jug and fill with water. Add one tablespoon of Dawn or similar dish wash soap. Mix thoroughly. Cool the surface of the trailer with cold water first. apply the mixture from the bottom of the trailer to the top. Rinse from the top down. Wear rubber gloves and eye protection. Do not allow solution to dry on surface before rinsing. Test a small area first.
I would then coat the aluminum with a product that contains real Carnuba wax.. Note: Harsh cleaners will quickly remove the wax.
This is what I would try. Use your own judgment of how the small test area works.
However, if you can find a product that contains up to 25% phosphoric acid, up to 5% Hydroxy acetic acid, , up to 5% 2-Butoxyethanol, and up to 1% Nonyphenol Ethoxalate; you will have a product that does not harm the aluminum but will remove the oxidation. The company I work for has such a product but we generally do not sell to the public.
Larry

[qft]

That's interesting to me, Larry. I've seen plenty of people say that they get their aluminum campers acid washed (many at truck washes) 1-2 times per year and it works phenomenally. I feel like I'm missing something between their comments and yours.

I can try that solution you mentioned. I tried straight-up vinegar earlier and it didn't seem to do a thing. I don't think my aluminum has a finish on it; I think it's just brushed or milled - but I'm not positive.

[Rolly]

Look at some of the Airstream forums. Someone with an Airstream has probably had to solve this problem.

Gary

[halfdome, Danny]

I'd first try to machine buff out a small area with some Mothers Aluminum Polish.
If the pits still remain then you'll need something more aggressive.
You could try a DA sander (dual action) starting out with somewhere around 100 grit and going up in a finer grit until it cakes on the sandpaper, then back with a buffer and Mothers Aluminum Polish.
You'll need lots & lots of clean rags and stainless steel cleaner (has mineral oil in it) will help remove the black aluminum residue.
It's a messy job and needs a lot of commitment on your part.
I cleaned up some severely scratched mill finish with 80 grit and up along with the same polish.
It looked gorgeous when I was done but be forewarned it's a ton of work (a months labor) and you may want to hire it out.
Danny

[Java Jack]

I have been told that it takes a LOT of elbow grease along with a mix of Flitz metal polish and Walbernize cleaner but that it will restore it to a new looking finish. Then put a coat of Woody Wax on it every 6 months to keep it looking new.

I have not yet tried it but it is supposed to be fantastic once done.

[dales133]

A cut and polish after a clean as mentioned earlier should do the job
You could try a decent car detailer

[deleted]

I recently polished only the inside of my door with Mothers Aluminum Polish because it had a small black rub mark from something that was touching during transit last year. I second and third what everyone else said but I will stress even more it is a LOT of work and will take a LOT of commitment. It took days to polish the rest of the door, several filthy rags, and a ton of elbow grease. I would only undertake polishing it again if I had kids who were frequently bad so that polishing the door can be their punishment the next time they did something wrong In retrospect I should have found or made a cute sticker to put over the mark. If you ever see my trailer at a rally and the inside of the door is covered in stickers you'll know why

[dmdc411]

My dad "had" a 1947 Cessna 170 that was originally polished, then painted. We stripped it, tried to polish it, had most of it looking good. Then moved on to the motor rebuild. Went back to add stripes to the fuselage, the oxidation had came back. We learned 2 things, once corrosion starts in aluminum, it comes back very fast unless it's painted. Other lesson, it's alot of work to keep up, so if you start, don't stop! Aluminum is very corrosive, especially the stuff we're using here. Alloys are not as bad, but they also have very thin layer of raw aluminum to seal the alloy.

[angib]

Also remember that an aluminium oxide surface is what protects aluminium from further corrosion, since the oxide is fairly tough - it's like a self-painting metal!. Polish off the oxide layer and it will have to 'grow' back - indeed any 'bare' aluminium we see is aluminium with only a thin oxide layer, since bare aluminium doesn't stay bare for more than a few minutes.

Anodised aluminium is just aluminium with an artificially-generated thicker oxide layer and that protects against most things, including sea air.

[RunnerDuck]

I just tried cleaning my bare aluminum with "Bar Keepers Friend" and it appears to do a great job. It's mainly used on stainless but looks like it works in a small area.

I'm not going for a chrome shine only to remove some stains and make the whole surface look even.

Others have recommended "Cream of Tartar" and water paste but I believe Cream of Tartar is abrasive.

Thoughts?