Corrosion in Al heat sinks with water channels

[Skogsgurra]

How do you best prevent ordinary cooling water from corroding aluminum?

The water runs through channels inside the heat sinks and has now corroded the heat sinks so badly that water drips/runs from them. Is there any additive or treatment available to stop this from happeneing in the future (new heat sinks will be installed) or is there any Al alloy that is corrosion resistant?

Gunnar Englund

http://www.gke.org

 

[kenvlach]

Closed (recirculating) cooling system?

Probably easiest to add a commercial automotive antifreeze suitable for aluminum engines & cooling systems. Use with chlorine/chloride-free water.

Is this Al 6063? (maybe the most commonly used extrusion alloy in Europe). If so, it's normally rather corrosion resistant. Some 5xxx alloys are better when Cl[sup]-[/sup] is present, like those used for marine applications or automotive bright trim.

See aluminum alloy information at

http://aluminium.matter.org.uk/aluselect/02_corrosion_browse.asp

 

[Skogsgurra]

Thanks kenvlach,

Yes, closed system. I'm glad it isn't mine. The extrusions are probably European. Water comes through after four - six years.

Gunnar Englund

http://www.gke.org

 

[EdStainless]

Regular auto antifreeze. For corrosion protection a 25% solution should be enough. I presume that the electrical properties of the water don't mater.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[aviat]

The mixture should be checked yearly, even if only a PH test because the additives wear out.

http://www.polarislabs1.com/source-water-levels.htm

These sites are from an engine system but are applicable to other systems. If you have a bad ground or other electrical problem, it can set up stray current corrosion that destroys your engine. I talked to a person recently, who went through two rads in his car in less than 6 months, due to this. The site shows how to check for it.

http://www.polarislabs1.com/electrical-test.htm