Whilst installing I encountered a few problems… not so much the new kit; but my old one. I’ve been running my old DD system with some UV additives and the older version of the maze4 GPU also reviewed here. The problem is that it’s anodized aluminum… and through the years I noticed my water kept losing the UV color and the hoses kept on getting black. I drained the system a few times and refilled it with distilled water and some UV pigment, but within a month it went black again, so that’s when a little light bulb started to show above my head.
Galvanic corrosion, the copper and water were eating away the aluminum in such a way that if I continued to use that system for another 3months I’d have water coming out of the GPU block! Yes, it was that bad, somehow I think DD knew this too, as all the new maze4 GPU’s and Fillports are now made of another material other than anodized aluminum.
To quote some Wikipedia:
Galvanic corrosion occurs when two dissimilar metals are placed in contact with each other in the presence of an electrolyte, such as salt water, resulting in the unintentional formation of a galvanic cell and concomitant chemical reaction of the metals involved.
There are several ways of reducing and preventing this form of corrosion. One way is to electrically insulate the two metals from each other (for example by using plastic or fiber washers to separate steel water pipes from copper-based fittings) or by using a coat of grease to separate aluminum and steel parts.
Another way is to keep the metals dry and/or shielded from ionic compounds (salts, acids and bases), by encasing the protected metal in plastic or epoxy, for example. Another method, called “cathodic protection”, uses one or more sacrificial anodes made of a metal which is more active than the protected metal. Metals commonly used for sacrificial anodes include zinc, magnesium, and aluminum. Finally, an electrical power supply may be connected to oppose the corrosive galvanic current. (see Impressed-Current Cathodic Protection)
More info found here.
The damage to the GPU block was extensive and not usable in a system anymore, I cleaned the older blocks with some Hydrochloric Acid, so those where still useable, so that just goes to show that different metals inside a watercooling system = BAD news.
