* Chris Jones <cjns1...@gmail.com> [100214 02:35]: > Has anyone with real world experience in the area of computer cleaning > tried such solutions as the MetroVac duster line and might be able to > comment on the respective merits of air compressors vs. air cans..?
The telephone company uses dry nitrogen to purge telephone cables (sealed conduits which contain hundreds of twisted pairs). The short answer: There is no practical way for a small user to produce compressed air which is free from oil vapour and moisture; the proper solution is dry nitrogen. More detail: In petrochemical plants, from time to time there is an air line fire in which combustion takes place within the line; the steel pipe of the line (which may run hundreds of feet) grows red-hot and sags in the pipe rack as the combustion progresses from one end of the line to the other. This can happen when the oil vapour is not removed after the air exits the compressor, and when a large compressor is in continuous service. The oil comes from the compressor lubrication system. The amount of oil coming out of a small home compressor generally is too small to be hazardous. The oil problem does not exist with small diaphragm-type compressors. Water is another matter. Almost every mechanic has experienced a slug of water which makes its way down the line and out a nozzle or into a pneumatic wrench. This is because condensate traps are not perfect, and they don't always get emptied routinely. Water is bad enough, but hardly anything makes a worse mess than a spray of oily water. I doubt that it is possible to get a computer board or power supply cleaned properly up after being sprayed with oily water; the only hope would be immersion in a capacitor-safe, plastic-safe solvent such as freon, and even that would ruin the fan bearings. How-to: Any welding supply house can sell you a tank (2000 psi) and regulator with gages for dry nitrogen, just like the telephone company uses. And they can fix you up with a hose and nozzle with a pushbutton valve. When you finally empty the tank, you haul it back to be refilled. Just make sure that the tank which you purchase is one which is intended to be privately-owned and make sure that you hang onto the receipt. Many tanks have a welding supply company name forged or deeply stamped into the neck of the tank. So, for example, if you have a tank stamped "FOO Welding Supply" and you take it to BAR Welding Supply to be refilled, BAR may refuse to fill the tank; this is because theft of tanks is a major problem; that's why the expensive markings are manufactured into tanks. So ask about third-party refilling before you purchase a tank. Rental of a tank is too expensive for the individual user; this is because a daily "demurrage" charge accrues after the first 30 days. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100214105320.ga3...@rlharris.org
