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DM water leaves black stain on aluminum machined jobs

May 6, 2008

Our company is into fluid management with automobile manufacturers and its ancillaries. Majority of our customers machine aluminuim jobs. Every one of them use DM water for mixing in coolant. Very often we face problems of black stains apearing on job either in machining process itself or when the job is kept idle on the fixture after machining during lunch hours.

48707

Suprisingly these black stains do not appear when we add ground water in the emulsion. But machine manufacture does not recommend to use ground water as it will rust the machine bed,guideways and chucks.

Please let us know if DM water is the culprit or there is some other reason. If DM water is the culprit. What should we do? What value of TDS & pH should we maintain to avoid black stains appearing and at the same time the machine should not get rusted?

Waiting for your advice.

Regards.

Abbas.Shabbir Vadnagerwala
Supplier - Chennai, Tamilnadu state, India

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