DIN insert corrosion/cleaning

[Panstey77]

Hi ScubaBoard,

I have recently received a set of tanks which had the DIN inserts corroded into the tank valve. After using an allen key and hammer, I was able to remove each of the inserts. However, they were badly corroded/dirty. I have soaked the inserts in white vinegar and scrubbed with a toothbrush to remove the salt and grime build up. In some areas, the inserts have changed colour to a red-pink.

Please can anyone confirm what this is and if it is damaging to the inserts (picture attached)? Thnx

 

[Diving Dubai]

The pink colour is the copper electroplating showing where the chrome plating has come off.

It's not a huge issue depending on how often you remove the inserts. All the "work" is done by the O-rings front and rear.

If it's a concern to you new inserts aren't expensive

 

[Scared Silly]

Soaking in undiluted table vinegar which is between 4 and 8 % acetic acid will remove the chrome. One should use a diluted 50/50 mix of water/vinegar. At this point with the chrome missing the inserts will corrode more easily. As such, if you are using them I would regularly remove and clean them. You can lightly lubricate the threads with some christolube or O2 compatible lubricant which will give some additional protection from corrosion.

 

[rhwestfall]

lube might lead to trapping fine material..... if it bothers you about the missing plating, replacement plugs can be gotten fairly inexpensively...

 

[happy-diver]

the copper patina is beautiful, it's just the brass reacting to the vinegar

but the protrusion at the rear will preclude you from fitting those inserts into some valves
and the 014 oring at the front will introduce you to oring tearing sealing hell

polish them for earings