Chemistry question on aluminum


Hi,
I am not sure if I am getting paranoia about this...

Nowadays, there are many equipment (amps, speakers, etc) that are made from aluminum; from a slab, ingot, extruded and other processes. And I am a sucker for the raw industrial silvery color Aluminum looks. I just dig them. (Think YG acoustics, Audiomachina, Modwright, Jeff Rowland, Acoustic Signature TT, et al)

But I live in the hot and humid tropics. A friend, knowing that I failed Chemistry in school, put a scary thought in me that white powdery substance will form and corrode them in the long run.

Anyone care to give me a Chemistry 101 lesson on this with respect to Audio equipment?

Thanks.
hamburger
Aluminum melts at 1220˚F, so depending on how hot it is where you live there could be concerns. Just something to be equally paranoid about.
Unless your listening room is situated on the face of the planet Mercury, I don't think I'd worry too much about high ambient temps...

-RW-
I never got my PhD, but I did have a beach house at one point. A quick glimpse at the coated aluminum frames of my deck furniture will confirm that salt air is not good for aluminum.

Marty
First response is the one that makes practical sense. Would any of you have sympathy for or buy anything from a neglectful lazy pig who after spending good money on gear lets it rot, never paying attention to it's appearance? My goodness! Wipe it off with a damp cloth once in a while, dust it off, don't use it as a coffee table and spill beer on it. Take the same care as anyone anywhere and it'll still look great 20 years later.

Caveat: don't forget to take the lid off and blow it out with compressed air too.
As mentioned Drrsutliff, the surface of aluminum oxidizes to create a coating of aluminum oxide. This surface adheres strongly to the aluminum and protects the unoxidized aluminum beneath it. Steel, as we know also oxidizes, however this creates rust which progressively falls away from the metal beneath thus allowing the oxidation to spread.

If aluminum comes into contact with salts or caustics it will cause the oxidizes to go on and spread like rust on steel.

Anodization of aluminum thickens the hard oxide layer and increases the protection against corrosion. This is generally sufficient for most applications.

I live in Quebec. We are not close to the sea but during winter the cities spread copious amounts of salt on our roads. IME The salt seems to have little impact on aluminum wheels. Mind you, I remove my al wheels and replace them with old rusty steel rims. Many other car parts are also made of al such as engine blocks and heat exchangers. I have never heard of them failing due to corrosion.

All this to say, that for audio applications I would not be the least bit worried with use of aluminum. The question is are there other materials, for audio applications, that will perform better such as carbon fibre or Kevlar?

Formerly, I worked for a leading aluminum producer.

As for toxicity, aluminum is not toxic and eating from it is in no way dangerous. Good luck not eating food that is or was in contact with al. Think al foil.

As for the link with Alzheimer's, my understanding is that al is found in the brains of patients but that arrives their "naturally" and is not a result of exposure.