Strange white powder on inside and outside of CO2 lines

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jamorgan3777

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Hello all!
Been a long time since I posted anything. Have not really been active in the homebrew scene for a while, but getting ready to get back on the horse (or induction burner rather).

While going through and reorganizing my brewery, I wanted to do an overhaul of my keezer. When I popped the lid, I saw (again) something that has baffled me and I am hoping someone else has run into this or seen it before. My CO2 lines, over time, build up a white powder, both on the inside and outside of the line. Seems weird to me that it would be on both sides of the line. Its not frost or frozen condensation, if I get some on my finger, its stays for quite a while. It feels almost soapy or waxy. If I had to guess I would say it feels like teflon powder. Another observation is that if it sits longer and warms to room temp, it turns into a clear liquid (almost melts?) like an oil of some sort. The strange thing is that its on both sides of my lines.

Possibilities:
a. Its coming from the CO2 tank - Would not be on the outside of the lines thought, no slow leaks or any leaks. The tank has been open and pressurizing the lines for a couple of years with no losses.
b. Its coming from the freezer - I then thought it might be leaky freon from the freezer, but why would that be inside the line. That is sealed.
c. Its coming from the lines themselves. Some additive that is inside the tubing is plating out after hundreds of heat/cold cycles. This is the only thing that makes sense, but the tubing is not damaged or appearing to change in any way (not getting brittle, discolored, opaque, etc.)

Short of bringing some of it to work with me and having it analyzed, I am not sure what it could be. Has anyone ever seen this or anything like it. It is very white and very fine (imagine if you dusted the lines with powered sugar). I have my (purchased new) tank filled from time to time at the local welding place, but they are the same ones that fill tanks for multiple food applications (soda, beer, etc.).

Thanks!
 
What material are your lines made from? Could it be a plasticizer blooming from the polymer? Those will tend to be oily feeling.

The most common plasticizer for PVC (assuming that is your material) would be DEHP (Diethylhexyl phthalate), which doesn't freeze until - 50 °C, or so. If it's a degradant of the plasticizer, then it may different freezing/melting point. I have experience with the exposure of plasticized polymers in acidic environments causing blooming of the plasticizer, particularly in DEHP-plasticized PVC.
 
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How long have you been using this line set? Is it only the co2 line of both co2 and liquid? (I assume both co2 and liquid are the same material and age)
 
The lines are all of similar age. I noticed it mostly on the exterior of all the lines, but the interior of the gas lines. I am assuming that whatever is in there is in the beer in the beer lines. I had taken to tossing the first pour.

Since this post, I have stripped the entire system and replaced with new lines. I have been cooling it for a couple of weeks now and have no signs of the powder. Will be a few more weeks before I get a keg in there so I will just watch them with no CO2 on them. and see if they build up
 
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