Metal Finishing Guide Book


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Table II. Bath Parameters Acid Chloride Zinc Wetting agents, refining agents or carrier Alkaline Non-cyanide Zinc Cyanide Zinc 2.0���5.0% vol./vol. 1.0���3.0% vol./vol. Not applicable Brightener 0.05���0.2% vol./vol. 0.05���0.2% vol./vol. 0.2���0.5% vol./vol. Temperaturea 60���130��F (15���55��C)1 60���110��F (15���48��C) 60���110OF (15���43��C) a Positive and negative effects are observed when a bath is operated above room temperature (75��F): ��� Because of the solution evaporation, bath buildup problems can be minimized or eliminated. ��� At higher temperatures, higher conductivity means less power consumption. ��� Plating speed is increased at higher temperatures. This means less plating time is required. ��� Operating at higher temperatures means savings in refrigeration cost. ��� At elevated temperatures, brightener consumption may be higher than at room temperature. ��� The solubility of organic additives can become a negative factor. 1 New high-temperature chloride zinc systems for barrel work have reduced plating time 10���50% and increased production 30���100%. SAFETY CONCERNS The characteristics of zinc plating baths deserve consideration due to possible safety hazards. While acid chloride zinc and alkaline non-cyanide zinc result in no toxicity to humans, cyanide zinc is highly poisonous. Platers should remember that the formulations of acid chloride zinc baths make them corrosive to equipment. Alkaline non-cyanide and cyanide baths are noncorrosive to equipment. Exposure to the chemicals in alkaline non-cyanide zinc and cyanide zinc baths can be corrosive to living tissue, whereas acid chloride zinc appears to have little BRASS ��� COPPER ��� BRONZE ��� OVAL F L AT ��� ��� ��� ��� B A L L ��� ROLLED C A S T ��� Our PLATING ANODES Will Make You Look Good ��� T I N ��� ��� S O L D E R Belmont���s renowned customer service saves you time and money. F L AT T O P ��� V I S I T L E A D CADMIUM ��� NICKEL ��� ZINC ��� ��� Tel. (718) 342-4900 ��� FAX: (718) 342-0175 ��� 368 SPECIAL SHAPES Add value to your plating anodes purchase with the highest quality, most cost-effective product. We offer a large inventory of metals and shapes. ���

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