How do I keep aluminum from oxidizing

[HiTek21]

I have a nice aluminum strut tower bar that came off my car but it has some dings that I would like to sand out. I was thinking I would use 1000 grit sandpaper, move up to 2000 grit, and buff it out with some aluminum polish but will that keep it from oxidizing or will I have to coat it with something special?

 

[Eli]

Aluminum is pretty resistant to corrosion by itself... well, depending on the alloy I guess.

Is it showing signs of corrosion already or something?

lol, you could wax it after polishing.

 

[Analog]

its tough without altering the color / tone i.e. anodization. Sprays may help, but they can peel over time.

 

[Kadarin]

Keep it away from oxygen... duh!

 

[Insane3D]

Get some high temperature clear spray paint and give it a good spraying after you clean it up...

 

[HiTek21]

I was thinking I would have to apply some kind of spray over the bar. The bar itself looks like it was just machine finished because you can still see milling marks all around the bar. The top of the bar itself has a semi glossy finish but if you feel it or look closely you can see machining marks.

 

[FlashG]

no-ox

 

[Rastus]

I have some no-ox, but it is like grease. There are some coatings out there for aluminum, alodine is one of them, but they do discolor the aluminum.

 

[Vegito]

http://www.rustoleum.com/product.asp?frm_product_id=29&SBL=1 i guess stuff like that but in a spray... google for aluminum primer stuff

 

[kitkat22]

Actually for the most part oxidized aluminum is ok. When aluminum oxidizes it coats the pure aluminum underneath protecting it from oxidation. The catch is, unlike iron, the aluminum rust doesn't easily come off and if it does the exposed part of pure aluminum oxidizes to form a coat again. This is part of the reason aluminum is used to extensively.

 

[dullard]

Aluminum oxidizes within a few seconds of being exposed to air. So if you think you can prevent it, you better think again. Those aluminum pop cans are actually partially aluminum rust.

 

[Kenazo]

I've heard that mercury paste is the best thing to use. You just smear on a thin layer like grease...

 

[Fenixgoon]

if you let the aluminum oxidize, the aluminum oxide will actually act as a protective layer that prevents further oxidation. the AL2 O3 also makes it corrosion resistant

 

[Kenazo]

What no one got my mercury joke?

 

[mordantmonkey]

Originally posted by: Kenazo
What no one got my mercury joke?

you forgot to tell him to heat it up first... in a pot on his stove. and to make sure to keep smelling it, to make sure it doesn't burn.

 

[thelanx]

I agree with the others that say than aluminum oxide doesn't flake and instead protects the rest of the aluminum, so you have nothing to worry about.

PS you can also try the aforementioned "mercury paste" if you'd like to be mad as a hatter.

 

[91TTZ]

Originally posted by: dullard
Those aluminum pop cans are actually aluminum rust.

Where do you come up with this stuff? They are plastic coated aluminum.

 

[Kenazo]

Originally posted by: mordantmonkey

Originally posted by: Kenazo
What no one got my mercury joke?

you forgot to tell him to heat it up first... in a pot on his stove. and to make sure to keep smelling it, to make sure it doesn't burn.

psshh... All mercury needs to do is get beneath the aluminum oxide layer and it'll do its magic. All it would need is a scratch and that would be the end of his piece of aluminum.

 

[dullard]

Originally posted by: 91TTZ
Where do you come up with this stuff? They are plastic coated aluminum.

From my education as a PhD in chemical engineering. Sorry, I don't have all my textbooks here for references, but you can do a quick Google search if you want.

Link 1: "If a bare aluminum surface is exposed to an oxygen containing atmosphere (e.g. air) then a very thin layer of alumina (far too thin to be visible to the naked eye) will form very quickly, even at room-temperature".

Link 2: "Aluminum oxidizes very quickly, and rapidly forms an aluminum oxide coating that inhibits further oxidization."

Link 3: "Metals in the reactivity series from aluminum to copper react with oxygen in the air to form the metal oxide. Aluminum is the fastest and copper is the slowest of the six."

 

[Mo0o]

Originally posted by: dullard

Originally posted by: 91TTZ
Where do you come up with this stuff? They are plastic coated aluminum.

From my education as a PhD in chemical engineering. Sorry, I don't have all my textbooks here for references, but you can do a quick Google search if you want.

Link 1: "If a bare aluminum surface is exposed to an oxygen containing atmosphere (e.g. air) then a very thin layer of alumina (far too thin to be visible to the naked eye) will form very quickly, even at room-temperature".

Link 2: "Aluminum oxidizes very quickly, and rapidly forms an aluminum oxide coating that inhibits further oxidization."

Is that the same as this? http://www.madsci.org/posts/archives/feb98/886512781.Ch.r.html

 

[dullard]

Originally posted by: Mo0o
Is that the same as this? http://www.madsci.org/posts/archives/feb98/886512781.Ch.r.html

Yes, cans do have liners. But those liners go OVER the aluminum oxide layer. It just develops to fast to avoid. I never said cans don't have liners.

 

[Mo0o]

Originally posted by: dullard

Originally posted by: Mo0o
Is that the same as this? http://www.madsci.org/posts/archives/feb98/886512781.Ch.r.html

Yes, cans do have liners. But those liners go OVER the aluminum oxide layer. It just develops to fast to avoid. I never said cans don't have liners.

So the cans are only made from the alumina? But I thought the layer was far too thin to be visible, wouldn't most of the can be made from real aluminum? Or do they harvest the alumina somehow and make the cans from that.

 

[dullard]

Originally posted by: Mo0o
So the cans are only made from the alumina? But I thought the layer was far too thin to be visible, wouldn't most of the can be made from real aluminum? Or do they harvest the alumina somehow and make the cans from that.

Yes, most of the can is real aluminum. But my point is the same: you can't completely "keep it from oxidizing". A thin oxidizing layer can and WILL form.

 

[Mo0o]

Originally posted by: dullard

Originally posted by: Mo0o
So the cans are only made from the alumina? But I thought the layer was far too thin to be visible, wouldn't most of the can be made from real aluminum? Or do they harvest the alumina somehow and make the cans from that.

Yes, most of the can is real aluminum. But my point is the same: you can't completely "keep it from oxidizing". A thin oxidizing layer can and WILL form.

Oh. Your very first post was kind of vague then. "Those aluminum pop cans are actually aluminum rust. " makes it sound like the whole can is made from rust. This is oxidation is just like what happens with solide sodium or potassium right?

 

[Kenazo]

Originally posted by: Mo0o

Originally posted by: dullard

Originally posted by: Mo0o
Is that the same as this? http://www.madsci.org/posts/archives/feb98/886512781.Ch.r.html

Yes, cans do have liners. But those liners go OVER the aluminum oxide layer. It just develops to fast to avoid. I never said cans don't have liners.

So the cans are only made from the alumina? But I thought the layer was far too thin to be visible, wouldn't most of the can be made from real aluminum? Or do they harvest the alumina somehow and make the cans from that.

Did you take Chemistry in high school?