The authoritative public forum
  for Metal Finishing since 1989
-----

Need assistance finding an effect reagent or other methods of detection of potential contaminants.

We periodically experience localized adherence deficiencies on our products at our copper plating operation.

We have changed out all of our cleaning tanks and our copper plating tank, implemented a disciplined PM schedule and still experience a periodic problem.

Although we perform titrations to allow us to maintain an effective concentration of cleaner in our tanks we do not have an effective method of actually verifying that we have a clean and contaminant free product prior to copper plating.

Is there any reagent or other method used to detect any remaining contamination on parts immediately following the cleaning process prior to the actual copper plating process?

Bruce Rigard
Director of manufacturing - Daytona Beach, Florida
March 17, 2008

---

Look up water break in past letters. Along with that, you need an operator with a calibrated eye. James Watts - Navarre, Florida Mr.Bruce I READ YOUR PROBLEM PRIOR TO PLATING, WHAT KIND OF YOUR PROCESS?, YOUR PARTS HAVE TOO MUCH COMPOUND ON IT OR GREASE OR CARBON IN PARTS? IF YOU HAVE ADHESION PROBLEM OR OTHER CONTAMINATION.WE NEED TO KNOW MORE DETAIL YOUR PROCESS TO HELP YOU OUT. Popatbhai B. Patel electroplating consultant - Roseville, Michigan Let's go after your problem of adhesion from a different angle. Please tell us the base metal alloy we are depositing copper onto. Is it leaded steel? Is it leaded brass? Is solder or braze smeered over the place where you lack adhesion. Show us a digital picture. Send me a digital picture. What thickness cvopper are we plating. What is copper electrolite and is it subject to high chloride contamination or lead contamination from leaded parts. these ae the conditions we want to know in order to address yuour lack of adhesion. And OH, have you looked for floating soil, oil, stamping oil, hudraulic oil on the rinse tanks and the copper aplting tank? Robert H Probert Robert H Probert Technical Services Garner, North Carolina From the tone of your post, you seem to be looking for something like a spot test. Unless you are looking for a specific contaminant, you won't find anything like that. There are methods to detect contamination, but to recommend one depends on a whole lot of factors, including the nature of the soil, the geometry of the part, the type of plating line, the basis material, etc, etc, ... James Totter, CEF - Tallahassee, Florida

In order to help you it would be necessary for you to provide more information. What type of substrate? What is the full pre treatment sequence and chemistry. What type of copper plating? Bath chemistry, etc.

Gene Packman
process supplier - Great Neck, New York
March 20, 2008

---

March 27, 2008

Thanks to all for the replies on my questions about the intermittent adhesion problem we are experiencing at our copper plating operation.

Here is a little more information in regards to some of the replies.

We are plating cams shafts made primarily from 8620 steel

The steel is not yet heat treated prior to the copper plating process.

The cams are cleaned in a caustic soap bath "unikleen tank" and then cleaned again in an "electrokleen tank" that is also a caustic soap, then pass through a HCl acid tank to remove the soap and rinsed and finally copper plated in a copper cyanide plating tank.

We are expecting contamination along the lines of transmission fluid or hydraulic fluid i.e. leakage from some of our older equipment used during the rough turning process.

The constituents in the fluids that we are suspecting to be contributing to the intermittent adhesion problems are silicon and or fatty acids.

Does anyone have a suggestion for a quick litmus test via a reagent etc. to determine if the cams are in fact clean or still have remnants of the aforementioned contaminants present prior to copper plating?

Thanks again for all your help.

Sincerely, Bruce Rigard

Bruce Rigard
- Daytona Beach, Florida

---

First of three simultaneous responses --

I think the easiest test you could perform would be a water break test. When a cleaned part is removed from the rinse prior to plating, does the water "sheet" off the part or does it bead up? If the water beads, the surface isn't clean.

I also noticed that the cleaners have been taken care of, but what about the rinse tanks? Has any PM been done there?

James Totter, CEF
- Tallahassee, Florida
March 28, 2008

---

Second of three simultaneous responses --

You say nothing about the parameters of the two clean tanks and how well you maintain them. There are a large number of possible causes, and we can only guess what they are, some based on personal experience.
There is zero excuse to let hydraulic fluid contaminate a part or a tank!
You do not remove the soap with HCl. That is done by proper rinsing. The HCl is there to etch and to activate the part.

A water break test has been discussed at this site tens of times if not hundreds. Read the old files.

What you really need is a qualified consultant for a few days.

James Watts
- Navarre, Florida
March 28, 2008

---

Third of three simultaneous responses --

I would suggest you review the basics first. Are the cleaning solutions being operated at the correct temperature and concentration? Are the rinses doing their job? Is the electroclean being operated at the correct current? Are the cycle times as recommended by the product manufacturer? Is the acid titrated for strength?

On to the copper. I would presume that you are using proprietary chemistry. If you are not, call a supplier.
Check to see that the bath in within the proper parameters for all chemical constituents. You should have agitation in the copper bath, but not from air. You either want to used pumped solution or work rod (cathode) agitation.

If one wishes to solve a problem one starts with the basics then moves on. The test for cleanliness would be worthless if you didn't know how to clean the part.

Gene Packman
process supplier - Great Neck, New York
March 29, 2008