Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site

Chime right in! (no registration req'd)

-----

"Blistering in Nickel Sulfamate Electroforming"





January 9, 2010

Q. I am currently using a nickel sulfamate tank for electroform plating. I just had a thorough analysis done by MacDermid labs and came back fine on all counts. However, the problem I am having has been ongoing for several years now. I use a silver conductive paint to provide conductivity to plastic and wax forms. I have used this for the last 20 years or so. Until the last several years I have had good success. Now I am finding I am blistering on all projects. Some more than others. When I start the plating at very low voltage and therefore low amperage the blistering is less, but not completely gone. I have tried changing cleaning preparations to no avail. I am wondering if dirty anode bags can be the cause of this by increase pull on cathode? Any ideas would be greatly appreciated.

Michael Murray
Plating shop owner - Toledo, Ohio, USA
^


January 12, 2010

A. Michael,

very likely that you have high compressive stress. Try dummy plating at high current density to remove excess stress reducer

Pat Mentone
Pat Mentone
St Paul, Minnesota
^


January 14, 2010

A. Michael, if you have changed the cleaners to no avail and McDermid confirms the bath is in spec, the only other things it could be are contamination of the nickel bath - try a Hull Cell and see how the nickel comes out on that; I assume you are using the same silver paint that you have been for 20 odd years, so it may be the paint has gone off and is contaminated with something, so try getting a sample of new paint and seeing if it still blisters. If neither of these solve the problem, what other things have changed in your process?.

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
^


January 26, 2010

Q. What can cause compressive stress? I haven't done a hull cell analysis yet, but when I plate just on steel/stainless steel without paint it seems to be ok.

Mike Murray [returning]
- Toledo, Ohio, USA
^


January 27, 2010

Q. A while ago we used an sulfuric acid reverse plating process. It is possible that drag out may have entered the nickel tank. Can this be removed by high amp dummy plating process?

Michael Murray [returning]
- Toledo, Ohio, USA
^


January 28, 2010

A. Michael

Compressive stress is usually caused by having too much of a sulfur containing additive in the bath. Usually these additives are ionic and not completely removed by carbon treatment. High current density dummying removes them rapidly since more sulfur plates out at high CD than at low CD.

Another way is to add NaCl or KCl. this will reduce the compressive stress and eventually cause tensile stress.

The dragin from an anodic sulfuric etch most likely contains sulfuric acid and metal ions. Most metal ions and sulfate ions increase the tensile stress and our not removed by high CD dummy plating.

Pat Mentone
Pat Mentone
St Paul, Minnesota
^


simultaneous January 29, 2010

Q. Pat,
Thank you for your response. After reviewing my last analysis it does show I have tensile stress in the 5,000 range. This shouldn't cause my problem I don't think. Would it be possible for poor contact from rectifier to anode and cathode cause pull away and/or blistering? I am still at a loss.

Mike Murray [returning]
- Toledo, Ohio, USA
^


January 30, 2010

A. I recommend to do first a copper acid coat 5-10 microns
and after you can coat with nickel without blisters
you also must wait 24 hours after painting before coating

Ricardo Burstein
Bnei Berak, Israel
^


simultaneous February 2, 2010

A. Do a Hull Cell test and look for contamination - it is a simple test to do and tells you one hell of a lot about the state of your bath

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
^


February 2, 2010

A. Mike

If you have high tensile stress you should start to see the deposit lifting around the edges. 5000 psi is high but not too high.

Some questions:
How are you measuring stress?
Is the substrate entirely covered with silver or is there also another metal exposed to the nickel solution?
Any chance the silver particles in the paint have separated from the paint base so you have areas of high and low conductivity on the surface?

One of my clients makes electrical contact in multiple places to the substrate. if one of the contacts has high resistance the silver actually gets etched away near that contact. Is this possibly what is happening?

Can you post a photo of the part.

Pat Mentone
Pat Mentone
St Paul, Minnesota
^


February 4, 2010

Q. I put a job in this morning at 44 asf. Job was about 6 sq feet. After 15 minute check, it looked great. After another 15 minute check it blistered all over the place. Help.

Mike Murray [returning]
- Toledo, Ohio
^


simultaneous February 9, 2010

A. Mike,
When you took your work out of the tank to examine it, you broke the circuit and the nickel will have passivated, especially if it is bright nickel. Any subsequent coating will not adhere to the first deposit and will blister. Repeat your test for 30 minutes but do not take it out after 15 minutes to check it.

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
^


February 9, 2010

Q. I haven't carbon-treated my tank since 2003, nor carbon filtered it. Also, I haven't run and LCD Dummy more than a few hours since that time. Would excessive metal and organic contamination cause this kind of blistering. Also getting cracking. Any comments would be greatly appreciated. Thanks!

 54056-1  54056-2  54056-3  54056-4

Mike Murray [returning]
- Toledo, Ohio, USA
^


March 1, 2010

My LCD dummy plate is covered with a dark shiny plate at about 3 asf. My last analysis showed no copper or iron contamination, what about silver contamination from the paint?

Mike Murray [returning]
- Toledo, Ohio
^


March 3, 2010

A. Mike ,
Is your ripple O.K .

Cair Shishani
Khair Shishani
aircraft maintenance - Al Ain, UAE
^

adv.   nickel how-to book

"The Sulfamate Nickel How-To Guide"


by David Crotty, PhD
& Robert Probert


published Oct. 2018
$89 plus shipping

Q, A, or Comment on THIS thread SEARCH for Threads about ... My Topic Not Found: Start NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact    -    Privacy Policy    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA