You guys have to see this just for the fun of it!
Custom PC's by Puget; Mineral Oil Submerged Computer
Oh, the detours one's research can take them into! But seriously, it's the liquid that counts. The intent is to raise the specific gravity of the coolant. A mixture of Mineral oil and Ethanol seems a good candidate. Looking into that mixture's characteristics as a possible azeotrope.
Shingoshi
2007.Dec.09 Sun, 04:00 --800 (PST)