Another common question about the indium sulfamate plating bath is what should be tested? One thing that needs to be tested regularly is the pH of the bath. Keeping the pH of a plating bath within certain limits is important to all plating baths. The pH should be 1-3.5, but 1.5-2.0 is preferred. In this case it is important to keep it the pH below 4. When the pH reaches 4, indium hydroxide, In(OH)3 (milk-white in color), will begin to precipitate out of solution. The pH can be checked with a pH monitor or with pH indicator strips. During reclamation and disposal of the bath you want to raise the pH to 7 with additions of NaOH or KOH to remove the indium from the bath by forming indium hydroxide, which like stated earlier precipitates out.
If you have any additional questions, please feel free to reach out to me or anyone else on the Technical Support Team by emailing us at [email protected].