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How to decrease solution dragout

I'm working as a plating engineer and we recently formed a team to battle our gold losses on dragout. We've been brainstorming on things such as rack designs, air knives, drip time, etc. Is there anyone out here who has a bright idea on how to reduce dragouts? We are plating gold on flexible printed circuits using automated PAL line.

Franz Cantillano
Plating Engineer - Cavite City, Philippines
2007

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2007

Franz,

I am not a plater but for a short time, 40 odd years, worked in the heavy plastics fabricating field

Hence I am not au fait with your dragout problem.

But in the Assay field for neutralization, we used a standard small diameter large tank with a high overflow.
The tank had a nice large drain outlet. The overflow pipe was large, say 6"Ø, but reduced down to a much smaller diameter pipe. The inlet piping to that tank extended DOWN and PAST that overflow pipe. The overflow pipe extended into the tank and had a very loose fitting cap. This cap was cut out. Then some el-cheapo cloth was wound over that inlet and, obviously, held in place by that cap. The object being that that 6"Ø pipe wouldn't easily plug up and could be very easily accessed.

The solids would collect at the bottom of that tank. Ah, and Assay work is often to do with gold losses.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

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In my opinion the place to start is where you take the parts out of the plating tank. Can you hold the parts over the plating tank and rinse them there so that the plating solution is washed back into the tank? It is easy for me because I have a manual line but that is what I do and it is so successful I only need to turn the gold recovery unit on once a fortnight. It is over 18 months since I made an addition to my nickel tank. Nick Clatworthy - Whitstable, Kent, UK 2007 2007 Hi Franz, From the time the side arm transporter horizontally transfers the rack from the gold plating tank to the next dragout rinse, there is a considerable amount of gold solution dripping. You can install a catching tray at the bottom of the rack that moves in and out. This tray can catch the dripping gold solution during rack transfer. You can check also the rack coating material. PTFE (halar) coating is better than plastisol. regards, Germie Maravilla - Manila, Philippines