Cleaning air cooler heat sink

[khangcao2k9]

A few days ago i decided to clean my system. Taking everything apart i noticed my air cooler heat sink got quite abit of dust on it so i decided to run it through water after reading a few posts on the interweb indicating that it's actually fine. But after letting it dry overnight i found a lot of white powder left on the fins. Could anyone help me as to what the powder is and how can i clean it because those will definately affect the cooler performance. Thanks
PS: i repeated the process 3 times now and there is still some a lot of powder left and they refused to be blown out.

 

[justin.m.beauvais]

The white powder isn't anthrax. So you are fine there. It is likely residual dust that was suspended in the water. It can be cleaned with a stiff bristle brush, paper towel, or may just blow off with compressed air. You could always wash it under the water again to see if you can get it to come off, but the brush will likely work best.

 

[ko888]

It's most likely mineral deposits from the water that was used or oxidation of the aluminum fins because water was left on it. Hard water will leave mineral deposits that can't be blown off. If you use distilled water it won't leave any mineral deposits. You should also use compressed air to blow out any remaining water droplets after washing to prevent the aluminum fins from oxidizing.