Oxidized QDs

[S-Met]

Oxidized QDs, title says all. I took two partial kegs over to a small bbq at a mates place. The next morning I stripped down the kegs, did a full Starsans soak per usual protocol, transferred the Starsans to a bucket for small parts cleaning and sealed the kegs so they are ready for next use. Next I dropped my small parts and lines in th Starsans bucket let them sit for a minute then set them out to dry, capped the bucket and called it good... or so I thought.

3 weeks later I open the bucket with Starsans for a quick sanitation and what do I find? 2 npt QDs and a nylon washer. Washer, fine, just like when it went in. QDs, seen better days. The smooth threads look corroded and discolored.

Anyone else have this happen? Were you able to salvage, or are they dead? Threads may still work, but I'm concerned about the rough threads being a fomite for contamination.

 

[day_trippr]

Interesting enough to make me take a look at the CMB disconnects I use for keg purging and CO2-push racking.

And they look pristine - and these are literally screwed into cheap 3/8" ID pvc tubing then worm-clamped, so they don't even take advantage of the captive O-ring wrt keeping seepage from the threads. All they ever see is beer and Star San - mostly Star-San for a couple of them.

So I can't say I understand what's going on in your case - especially that beer disconnect threads turning black, never mind all the obvious crud on both threads. What I do know is as long as the threads can lock up to a swivel nut, the captive O-ring will keep beer from ever reaching the threads...

Cheers!

 

[mongoose33]

I've had the same thing happen w/ QD's I left in Star-San for an extended period. I don't think they're bad at that point, what matters is really what's on the inside. If you can inspect the inside of the connectors, or run a pipe cleaner or similar through there and it's clean, I don't think it will matter.

 

[IslandLizard]

I have unintentionally left MFL QDs and other stuff in Starsan too over the years. The phosphoric acid in the Starsan eats away (corrodes) certain metals. The threads on MFLs are nickel or chrome plated brass, not Stainless Steel. I either had a few turn black or they were already black, not sure, like the one on the right. I don't know why or how that happens, I guess it's the acid doing that to the plating.

I've used a stainless wire brush the clean up the threads and they come out looking a bit better. When all the plating is dissolved there's brass underneath.
The seal is formed between the little plastic tippy and the flare of the (stainless steel) barb. The threads are immaterial to that, as long as the swivel nut can still be tightened on the threads.