Copy Cad - PH falls too low - 4.4

[charlton]

I am wondering why the pH of my Copy Cad solution fell so low ? Is this an isolated, one time occurance or does the solution "TEND" to fall as you electroplate more items in it?

Also, I have found it difficult to locate Ammonium Hydroxide locally so will be ordering a pint from Daigger.com.

Are there any side effects or consequences to the plating process or quality after raising the solution's pH with Ammonium Hydroxide?

Thanks

[seanc]

Charlton:

My zinc solution is sitting right at 6 Ph, and I've been using it for over a year. I estimate I've done 1000 sq-in (+/-) in that time.

Are you using an acid pickle pre-plate? Perhaps you're getting acid drag-in.

OTOH, I have NO information about what the Ph is supposed to be to begin with, and I never measured it until long after I had been using the electrolyte.

My Plating manual list the pH as "NE" = "not established"

Where are you getting the info to use ammonium hydroxide to adjust it?

Sean

[charlton]

Hi sean,

No, no acid - pickle. The parts are thoroughly cleaned, rinsed in plain water and dried before electroplating.

I have version 8 of their plating manual and it calls for 5.5 - 6 for the pH allthough it does say that lower pH's are ok...down to 4.6. Below that no good. I'm at 4.4 - 4.3

I'm thinking my solution "MAY" have been damaged by a malfunctioning thermostat. I just used my set up for the first time yester day and set the thermostat to it's lowest setting then insured that I had it plugged in so that the heating element was connected to the thermostat.

Anyway, it seemed that it was taking too long to shut off the heater so I measured the temp of the solution with a laser thermometer and sure enough it was a sizzling 165 F ! So that may be the reason for the low pH but I'm not sure.

After tapping the temperature sensor a few good times, it now seems to be working.

The manual also says ammonium hydroxide is used to raise the pH. But it costs a whopping $50 after Haz Mat fees and $13.00 shipping. (Seems like excessive shipping for a 1 pint container since they're already charging an additional $20 for haz mat)

I wish I knew of a local source. I'm dead in the water until I can raise the pH and that REALLY blows. I'm having trouble getting the plating to start now and I think this is what the manual says will happen with an excessively low pH.

Until this, GREAT results on my first 7 pieces. They look Chrome

I wonder if Zinc Brightener lowers pH ?

[seanc]

Charleton:

version 8 of their plating manual and it calls for 5.5 - 6 for the pH

So they've added that info since my manual, nice to know.

I'm thinking my solution "MAY" have been damaged by a malfunctioning thermostat

Since I'm still at the "ideal" 6 pH, and yours is too low, that's a good possibility. I'm no chemist, so I don't know what effect the 165º would have. Have you asked Caswell directly through their tech support?

The highest temperature I ever got to was 110º, for a one-time test (which didn't work), and it doesn't seem to have affected my pH.

I wonder if Zinc Brightener lowers pH ?

I don't know. It DOES affect electrolyte conductivity though, which is why I'm convinced that you need a CC power supply to get good consistent results.

Sean

[charlton]

The highest temperature I ever got to was 110º, for a one-time test (which didn't work), and it doesn't seem to have affected my pH.

What do you mean by that?

[charlton]

Since I'm still at the "ideal" 6 pH, and yours is too low, that's a good possibility. I'm no chemist, so I don't know what effect the 165º would have. Have you asked Caswell directly through their tech support?

No, not yet...maybe I should?

[seanc]

Charlton:

Quote:
The highest temperature I ever got to was 110º, for a one-time test (which didn't work), and it doesn't seem to have affected my pH.

What do you mean by that?

Early on, I had difficulties getting good plating, and was told to run the electrolyte at 110º. Although I had my doubts, I tried it at 110, and the results were worse. I've since found that 65-70º works best.

Sean

[charlton]

Wow...that seems too cold. Do you get good adhesion ?

[seanc]

Charlton:

Wow...that seems too cold. Do you get good adhesion ?

Yes, good adhesion, smooth & consistent plating. The temperature range is given as 60-90º, so that's well within parameters.

Sean