I can't put a coat of paint on the aluminium. It is an old stock P4 heatsink, acting as a chiller. It will be just about impossible to get paint into all those tiny places.
I've got some water-wetter I was planning to use. If I understand ShadowCat correctly, this will be just fine as an anti-corrosive. The water is coming from my dehumidifier.
It was a long time since I studied chemistry, so correct me if I'm wrong, but after some thinking I came up with this conclusion:
The galvanic reaction that will take place will move atoms from the aluminium heatsink to the copper water blocks, right? So eventually the heatsink will disappear and my waterblocks will have a thick layer of aluminium on the inside. As this layer gets thicker and thicker, the temperatures will raise. Since this process is significantly slowed down by using an anti-corrosive, I can expect only minor (if any) differences in temperature after a year or so.
Is this correct?