Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing 1989-2024
-----
Masking and Nickel Plating
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Q. Hello Everybody!
We got a question from one of our costumers who want to mask a certain part of a copper bar.
The size of the bar is 20 mm x 4 mm and it's length is 200mm. We have to mask this item 100 mm high each side.
We tried to mask it with plastisol PVC coating (the same type what we use for coating the frames).
Well, it was great it covers the Surface quite good but at the border were the masked part reaches the unmasked surface, the nickel got under the PVC a little bit (like 4-5 mm deep) and the surface of the copper bar became "wavy".
As they removed the masking after the plating they refused the quality and told us they want a Sharp edge!
How can I make the top of the PVC more "tough" to catch the surface better. Unfortunately the costumer told us it is forbidden to use the primer on this item.
Is there any other solution You could recommend us?
I hope it is understandable, I am not allowed to upload pictures of the part. (EV car parts)
Thank You for your help!
- Zirc, Hungary
September 1, 2024
A. Hi Vilmos.
I am not understanding how you "mask this item 100 mm high each side" when no dimension of the component exceeds 200 mm. Please clarify.
But what happens if you try "platers tape"? Get instruction from someone who sells it or uses it because it has to be pressed down very reliably with a roller if you want it to seal reliably.
Most plating textbooks are completely silent on masking, but Marvin Rubinstein's "Electrochemical Metallizing" [on
eBay,
Amazon,
AbeBooks affil links] and the ASM Metals Handbook Vol.5 [on
eBay ,
Amazon,
AbeBooks affil links]
cover masking at least a bit.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
⇩ Related postings, oldest first ⇩
Q. Hi,
I am a grad student at LSU. I'm trying to plate Nickel on a copper substrate using a citrate complexing agent. pH of 4.9 - 5.
The substrate is a copper plate with a resist of PMMA with holes of the dimension of 200microns width and 500 micron height.
The problem I am facing is trying a method to :
1. insulate the plate so that the insulation can be taken off without too many problems. I have succeeded in insulating it with electrical tape and a coating of resin above that...any better methods?
2. I am presently using a copper oxide film on the copper to ensure better adhesion of the PMMA. Is there a better method?
Amrit.
LOUISIANA STATE UNIVERSITY
1998
? What is PMMA?
Isn't the resist supposed to be the mask for the nickel? Sorry, I don't understand. Send us a GIF and we will post it here.
Tom Pullizzi
Falls Township, Pennsylvania
Q. Do you know of a masking material that can be applied selectively onto a copper plated mandrel and withstand a nickel plating bath for 8 hours @ 120 degrees without allowing under plating. This is an R&D project with great order potential if successful. We have been using masking XL-88 and MT-6000WB without much succsess. Any suggestion will be greatly appreciated.
Thank you.
Victor Parastschenkoelectrodeposited nickel bellows - Oakridge, New Jersey
2003
A. There is no reason that numerous commercially available maskants should not work. They do need to be applied correctly and for long or harsh plating cycles they will need to have more than one coat to prevent plating thru pinhole voids. You should have virtually no seepage under the masking unless you are using an unrealistic etch cycle. There is a possibility that you are not letting the maskant cure properly before the plating cycle. Some things from the same company work better than some of their other products. There are also several sources. Surely one of them will satisfy your needs if it is properly used.
James Watts- Navarre, Florida
2003
A. I'm answering my own question. After several weeks passed I called masking manufacturer and it was recommended that I mix 2 parts of masking with one part MEK / methyl ethyl ketone reducer. This worked well. I also tested with nail polish with teflon in it (wet'wild / speed zone) this worked even better, due to the fact is thinner and much better to apply for precision masking in intricate areas.
Victor Parastschenko [returning]- Cedar Grove, New Jersey
Q. Well...here goes...a friend of mine from work and I are trying to extend the life of the company we work for by saving on a product our company uses that we strongly believe can be replaced or not used altogether ...
WE PLATE NICKEL...we use plastic side sticks and bottom sticks on our rounds sheet ( a stainless steel sheet with buttons on it that...well...plate rounds) so..the plastic side sticks and bottom stick cost our company around 700,000.00$ /a year..we use the sticks because, if we don't, the sides and the bottom of the sheet will plate as well and this causes nothing but problems to the plating tank man and other departments that have to handle the sheet before it gets back into the system...the paint we use on the sheet does not cover the edges of the sheet well enough or it would be problem solved...(cost of paint is 150,000.00$ a year as well) ...so we look to you for help...is there a product out there in our day and age that
a). will NOT contaminate our electro plating processes
b). will be durable enough to handle temp.of about 500 °F
c). be dipped in an acid bonding tank for cleaning without it peeling away or at least peal away RIGHT AWAY (it's got to last a bit before re-painting)
d). can resist vibrations when we rattle our nickel rounds off for shipping (after being in the plating tank cells for 5 days at a temp of at least 200 °F)
Hope you can help us...we appreciate your time ...any suggestion even as far fetched as "well there's always NASA" might help ... remember, there is a ball park of 850,000.00$ to play with there ... anything is a savings ...ty
plating tank man - Canada
2004
A. Your problem is well known in the Electroless Nickel plating industry. Keep Nickel to less than 6 g/L. For plated tank, use 70% Nitric acid (concentrated) at 55 - 60 °C for removing the nickel. Don't paint it. Nitric acid will also slow down the deposition on the tank. A more environmentally friendly method is on the way, but may take more time to be accepted.
V T Damodaran- Chennai, Tamilnadu, India
December 20, 2011
Q. Hi
Can anyone help me. I am working with plating a bi-metal of steel and with a copper lead lining. The type of plate varies, some has a nickel underlay and then Pb Sn overlay. I only need to plate the Copper lead lining and not the steel. However I am having problems with plating the steel which means a lot of effort to remove after plate. Are there any ideas I am missing for avoiding this?
- Taunton, Somerset, UK
August 22, 2012
A. Guess what -- size, shape and locations make all of the difference in the world on how to mask. A picture(s) would also help.
James Watts- Navarre, Florida
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