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Old 2009-09-10, 12:46pm
NMLinda NMLinda is offline
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Join Date: Nov 21, 2008
Location: Herndon, VA
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Glad you got hold of Trey. I'm sure he had great pointers for you

Metalbone makes some very important points about choice of solvents and ensuring that these have fully outgassed before closing up your tank. Be aware that not all solvents work equally on all greases. For example, you might be tempted to just use isopropyl alchohol. All isopropyl alchohol does for many common cutting oils and greases used for machining is just hold the oil as droplets in a colloidal suspension - doesn't actually dissolve it, and tends to leave a fair amount of oil residue behind without a fair amount of vigorous mechanical agitation (like wiping or ultrasonic cleaning). Acetone is a little better, but leaves a thin film behind when it dries and will miss some oils. If you can get hold of a really strong industrial degreaser, one way to clean your tank would be several generous rinses with that, followed by several rinses of acetone, and finally by high purity isopropyl alcohol. The reason for the sequence is that each degreaser will attack different types of oils that might be present, and the IPA at the end removes the film acetone tends to leave behind. I used a process similar to this when I was building ultra pure hydrogen gas systems for semiconductor fabrication. I used solvents like benzene and MEK as the first solvents in a series of 4-5 solvents to clean the parts for my system. Note that benzene, for example, is carcinogenic and is always used under a fume hood in industrial applications like mine. I highly recommend you research recommended methods for cleaning high-pressure 02 systems. The process is likely to be similar, but there may be some good strong solvents you can use to precede acetone in lieu of things like benzene.

Good idea to test your set-up in the steel container you mentioned. If you can do it so that you're not in the container with it....ideal.
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