Mineral oil will not hurt the capacitors at least in the short run. I have tried it myself. As for the distilled water, you are correct about the corrosion and/or oxidation. Distilled water is fine unless it gain properties from other components. So basically it would be fine at first, but not after it reacts with the metal of the heatsink.
Well said! Another negative with distilled water is that from what I have been told, if the system isnt totally free of impurities "cleaned" the distilled water will rapidly build up its abiltiy to conduct electricity. Organisms will also begin to grow if something isnt added to it. I use distilled water myself, but I always put a touch of additive to it.
I thought that Folken was the one that had told me about a site, but I had him mixed up with someone else. In other words I dont know. Im setting up an old P550 as a server, Folken has a server that is similar to the one im putting toghether.
distilled water is not conductive. the problem is that as soon as it makes contact with any conductive material it suspends ions from that material and becomes conductive. this includes metal. especially the metal solder and housings on all of your internal components.
Jreb333 is correct as soon as you run the distilled water though your loop it becomes a possible conductor. That's why you leak test with everything unplugged except for the water pump, if it leaks there is no fear of harm to your components so long as you wait until it is 100% dry before you power up the entire system.