Question about corrosion

[A Bad Day]

I've seen a lot of air coolers that have copper in contact with aluminum.

What I'm confused about is that why are there little to no complains about corrosion after several years of use? I know the two metals will corrode each other if they come in contact.

 

[rubix_1011]

You would need some kind of solution to be in constant contact for this to happen such as very dense humidity/high dew point. The connection isn't really metal/metal as you have a thin layer of thermal paste between the metals which likely diminishes much of the possibility of any corrosion in a situation like this.

We really try to encourage people to avoid copper/brass in a loop with aluminium as this can lead to galvanic corrosion.

 

[farrengottu]

they dont use thermal paste between the metals, or at least ive never seen it when tearing old coolers apart. and copper touching aluminum does not cause corrosion, unless they have oxygen. which is only on the outside of the cooler. even with oxygen it takes decades for any corrosion unless you add electrical current then it could take just a few years. so coolers are plenty safe.

 

[A Bad Day]

I do recall seeing a stainless steel ladder held together with mild steel bolts, and it was stored in a low humidity area. There were lots of corrosion like this picture showed:

 

[rubix_1011]

I was thinking thermal paste between the IHS of the heatsink and copper base of a cooler...not different metals on the actual cooler...my mistake.