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Screen printing onto Electroless nickel Plating
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September 2, 2021Q. Hello,
6061 parts plated to 26074 class 4 grade A. We're now at a point where we're trying to ink mark the parts. Attempts at etching leaves us in a spot where the ink removes with a cloth and IPA.
I will say we're also in a spot of testing different inks to the grid below.
Epoxy based ink does stick and not wipe off, issue being round parts and they all need individual marking.
Parts are cleaned with vapor degreaser and left to dry. Handling is done with gloves.
Testing to date:
Clean, print and bake
Clean, plasma etch oxygen and argon, print, bake
Clean, plasma etch hydrogen, print, bake
Sodium Dichromate, print, bake - note solution was at 40C
ferric chloride [on
eBay or
Amazon] intervals of 5 mins from 5 to 60 mins submersion, print, bake
Testing coupons with different levels of phosphorous content as that can have an impact on adhesion of finishes also.
Seen mention of passivating the nickel plate, or even nitric etching. Curious if anyone seeing this note has tried/had success or failure with those or maybe options missed I'd love to hear about it.
- Minneapolis, Minnesota
A. Update for those with similar challenges.
We've now tested a number of different inks, surface preps and still to come an overcoat.
Cure temp and time is important, and since the manufacturers don't provide direction on what and how much here's what we've been up to. I hope someone finds this helpful.
Existing ink up to previous post have all been cleaned, printed and baked. We would put them in a convection oven for 30 mins to an hour at 250 °F.
IPA and a rag would wipe the Leibinger 142 black ink right off the part even though we "cured" it.
Now further testing of that same ink at different temps and times took it from a no-stick to extremely tough. Changing the bake up to 300 °F seemed to fair somewhat better against IPA wipe. 400 more so, and at 500 °F is impervious to IPA and even it's own solvent material MEK.
Pre-heating the parts has little to no effect.
We tried a hot air gun directly on the part for a limited amount of time at 750 °F thinking it would cure if the part hit 500f. No
Bake time and temp is key.
Also, just because it sticks to nickel plating with a 500 °F bake for an hour doesn't mean it will perform the same on stainless, or other finishes. Develop a process for each and be aware that may also mean a different ink.
- Minneapolis, Minnesota
Update 3 - final update
Cleaning method matters as well.
Two of the commonly used methods here are Alcohol wipe or vapor degrease. We found even with ink and bake temps mentioned earlier it was possible to have intermittent failures on parts only cleaned with IPA. This was found on subsequent tests again with IPA, MEK and a 3rd solvent after baking whereas the Vapor degrease method did not see any sort of failure.
- Minneapolis, Minnesota
December 17, 2021
Hi Travis. Thank you for sharing all of this with us!
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
December 2021
⇩ Closely related postings, oldest first ⇩
Q. I have a job requiring the screen printing of aluminium castings which have been electroless nickel plated with a satin finish.The paint originally specified for this job is no longer available. Other products to not fully adhere to the plating. Can anyone recommend any treatment of the plating which would permit good adhesion or a different type of paint. The surface of the plating cannot be abraded because that would destroy the finish.
Thanks
Regards
Michael Jeremy Hacking- Lancashire, England
2001
A. When you say paint, I think you are referring to a silkscreen ink. Make sure your part is completely clean of any oils after plating. Vapor degreasing works great. I would recommend a two part epoxy. Dexter-Hysol out of Chicago carries many varieties that can be successful. Also, are you baking after screening? If not, you may want to consider it. I have seen it work both ways, oven cure and air dry.
TED NOVOTNEHIAWATHA METALCRAFT INC. - MPLS, Minnesota, USA
2001
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