UV lights for checking tanks for hydrocarbon contaminiation?

[tep]

I've seen a few posts about O2 cleaning tanks that have mentioned using UV lights to check for contaminants? Is that the standard procedure? Any specific for UV lights, or pretty much any UV?

 

[mike_s]

I've seen a few posts about O2 cleaning tanks that have mentioned using UV lights to check for contaminants? Is that the standard procedure? Any specific for UV lights, or pretty much any UV?

I saw that also.... in another thread.... doesn't mean it's right.


I mean if you can see something with your UV light it might be contaminated.

But just because you don't see something doesn't mean it's O2 clean by default. I don't know where they came up with that idea.

 

[Blazinator]

If you have a HID light or LED, you can buy a cheap black light filter (Roscoe # 33650) for less than fifty bucks from any theatre lighting supply company. HID's put out lots of UV, and most oils will fluoresce under the UV light, but if the contaminants don't fluoresce, you won't see them.

 

[mike_s]

If you have a HID light or LED, you can buy a cheap black light filter (Roscoe # 33650) for less than fifty bucks from any theatre lighting supply company. HID's put out lots of UV, and most oils will fluoresce under the UV light, but if the contaminants don't fluoresce, you won't see them.

that above is so wrong.....

lots of compressors use synthetic oils now.... and they don't show up under UV light.

 

[oxyhacker]

Some time ago when we were looking into black lights, we took a sheet of metal and put smears on it of Dow 111 Silicone grease, some old non-synthetic compressor oil, some EZ1000 synthetic compressor oil, some O2-compatible grease, Krytox I think but can't swear, 5-20 motor oil and moly automobile grease.

The only one to really fluoresce to the extent that it was hard to miss was the auto grease. The motor oil did fluoresce ever so slightly, so a very carefull examination would probably have found it, and the non-synthetic compressor oil a little less. The others didn't fluoresce at all.

I tried the same test not too long ago with most of the previous lubes, and some Christolube 111. The Christolube did not fluoresce either.

So it is hard to avoid the conclusion that black light is ineffective at detecting the very contaminants most likely to be found in a scuba tank, valve or regulator.

 

[Blazinator]

I stand corrected.

My post was primarily to say that you can use your HID dive light as a black light with a cheap filter (good for coral fluorescing on night dives too), so I had less emphasis/knowledge on what will fluoresce. The olive oil splatter on my stove top lights right up with my black light, along with some other oils in the shop so I was going by that.