copy cad & zinc kit problem

[carb781]

I have been using the copy cad kit for a few years now and we always have the same problem, when the chemicals sit for a couple of months between usage's the plating is very dull etc., we always have to mix a new batch all the time and it gets quite expensive.Is there any way of spiking the mixture up to keep us using the same batch. we have tried adding brightener and this doesnt seem to help matters.

[XK120DHC]

I have been using the copy cad kit for a few years now and we always have the same problem, when the chemicals sit for a couple of months between usage's the plating is very dull etc., we always have to mix a new batch all the time and it gets quite expensive.Is there any way of spiking the mixture up to keep us using the same batch. we have tried adding brightener and this doesnt seem to help matters.

Have you tried a "Bright Dip" after the Zinc Plating? Not uncommon for many of us..
Also, are you going into a Chromate after Zinc Plating? Depending on the type/brand, the "Bright Dip could be a dilute measure of Nitric, HCI, etc. Each chromate has it's own preference..

[carb781]

Thanks charles, we do this already, the problem is the parts are coming out very dark grey almost a sandblasted colour, saying this we have filtered the chemical and things are a little better. How much bearing does the ph level have on the strength of the chemicals Don't want to sound stupid but this is only a hobby not my full time gig.

[XK120DHC]

Carb781;
All the parameters involved in plating are important to the final outcome, including the pH. The anode ratio, plating amps, etc. all need to be "just so" for the results to come out right. There is some latitude, of course, the "ranges" are listed in the plating manual.. follow the manual and you should be okay.. Generally, most of us are hobby-level platers.. Like anything, one must learn the processes involved if one is to expect decent results.
Lastly, you did mark the bath level on the side of the plating bucket after the initial mix, didn't you? This way, all you need to do is add distilled water to replace what is lost by evaporation.. The "chemicals" do not evaporate, and only the "Brighteners" are depleted during plating.

[woodjames]

Anyway you can post a pic

Thanks charles, we do this already, the problem is the parts are coming out very dark grey almost a sandblasted colour, saying this we have filtered the chemical and things are a little better. How much bearing does the ph level have on the strength of the chemicals Don't want to sound stupid but this is only a hobby not my full time gig.