My dear Mr. Völkel,

I read your article about the oil-cooled PC with great interest, but I have an improvement to suggest as regards the coolant you chose. You stated that water's clarity and transparency helped it make a better visual impression inside the case. My hair stood on end, however, when I saw you using deep-frying oil and then you also recommended motor oil.

There are two alternatives you might want to consider:

1. Neutral oil is a colorless oil that's half-synthetic in manufacture and that has a lower fraction of free fatty acids in composition. It's colorless and somewhat thinner in viscosity than cooking oil. You can purchase this type of oil in small quantities at any good drug store. Naturally, it's not as cheap as cooking oil - in part because it has valuable pharmaceutical characteristics - but I don't have exact prices at my fingertips.

2. Paraffin comes in various forms and is likewise colorless. It's a mix of hydrocarbons and petroleum distillates and contains no free fatty acids, which could cause corrosion - it's used to create a protective film on stainless steel in the pharmaceutical industry. Paraffin also comes in different viscosities: the thinnest varieties differ only slightly from water, while others are solid at room temperature.

These items are probably more costly than cooking oil, but they're almost certainly less expensive than most types of motor oil.

With friendly greetings,
Kai Hückstädt

Sven Reischauer: Cover The Board With Clear Coat

Hello THG-Team,

Great article on the oil-cooled PC. Because using cooking oil as a coolant also makes rancidity inevitable, I couldn't help but ask myself if using some kind of thorough clear coating on the circuit boards wouldn't help avert current flow in distilled water. This is best accomplished in a clear lacquer bath that's stimulated with current at 50 Hz, so as to cause the lacquer to penetrate every pore on the surfaces it coats. Remark: similar technology is used when pouring cement in the building trades. It has to be this way to counter the potential dangers of algae bloom that can otherwise occur. If I had time to try this out, I'd do it myself with an old circuit board. Do you have any interest in providing your readers with a sequel to your "PC water bath" efforts?

Sven Reischauer, Tübingen (Baden-Württemberg, Germany)