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Conversion coating rinse method

As a M.E. for a defense contractor I was tasked with looking into the benefits, if any, concerning the rinsing of parts during the Iridite process. Spicifically spray rinsing vs our present tank immersion. As present we use 130 gallon tanks, (1 tank per chemical). Fresh water is introduced only during the Iridite process. The surface area of the multi shaped aluminum parts range from 10 sq. inches to 32 sq. feet. As a guess I would say perhaps 50 to 60 sq. feet of surface area per week undergoes the process. Aside from less water usage, what are the positives or negatives to spray rinsing? What problems might be encountered? Will this be a process improvement?
Thank you,

Edward M. Schuse
Defense contractor - Buffalo, New York
2005

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2005

Hi Edward,

Without knowing the full details about your process, I can only say a few things in general about spray vs immersion. A spray process gives you the advantage of impingement. This mechanical action can be helpful in dislodging any soils or particles that are clinging to the work. An immersion system, however will alow the rinse water to come in contact with the entire surface area of your parts and may reach into areas that are out of the spray pattern. The more complicated the shape, the more difficult to get an effective rinse with a spray system.

All rinse systems must be overflowed vigorously to keep the tank as free of contaminants as possible. Water is your cheapest chemical and this is where many finishers like to skimp.

George Gorecki
- Naperville, Illinois