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Ted Mooney, P.E. RET
Pine Beach, NJ
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Cadmium Plating Touch-up
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Q. What is the best method of localized touch up for CADMIUM PLATE PER AMSQQP416 TYPE II, CLASS 3
Richard Sr.- Norwalk, California
January 18, 2024
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⇩ Related postings, oldest first ⇩
Q. Is there an easy method of touching up scratches/abrasions to electrical connectors that have an olive drab cadmium plating? The connectors are connected to cables, so they will require touch-up with a brush if possible.
Mike Kvamelectronics - Ronan, Montana, USA
2001
A. Hello Mike,
Brush electroplating has long been used to repair cadmium plating that has been worn or scratched off the surface of a metal component. Brush electroplating is a selective, portable process that will allow the operator to deposit metals such as cadmium directly on a damaged area.
The only problem that may arise is with the chromate coating. While olive drab chromate coatings can be applied to the cadmium plated area, the color of the newly chromated area may not be a perfect match with the existing coating color. The new deposit will meet functionality requirements but may fall a bit short on the cosmetic end if an exact match is required.
Chris Helwig- Valencia, California, USA
Q. I am looking for a touch up for Cad plating, I currently have connectors plated Cadmium per AMSQQP416 Type II Class 3, during our production process, the Cad is sometimes removed and needs to be touched up. I have tried a Alodine 1132 pen, and it will not adhere to the Cadmium surface, is there any other solution?
Howard IngersollOEM of Connectors - Georgetown, Texas
2005
A. Try Sifco SPS 5070 LHE Cadmium Brush Plating solution.
Frank DunleavyAerospace - Dublin, Ireland
Multiple threads merged: please forgive chronology errors :-)
Touching up chromate coating on Cad plate per AMS QQP416
Q. I work for a company that specializes in aluminium aerospace manufacturing, and we have an in house plating line for chromate conversion coating and anodizing of aluminum, as well as a few other applications such as passivation and titanium pre-penetrant etch. We send out to an outside vendor Cadmium plating to AMSQQP416 type II. Occasionally the surface of the Cad plate will get lightly scratched by handling or during assembly. The damage is only to the surface of the Cad and does not penetrate to the base material. Is there a generic process using sodium chromate, chromic acid, or some combination to touch up the chromate treatment that I could do here? Would it require a hydrogen embrittlement bake?
Corey JuddPlating shop employee - Cedar City, Utah, USA
2007
A. KISS it! Ask your cadmium vendor to give you a 1/2 pint of proprietary chromate solution for cadmium mixed up at 2X strength with the pH adjusted. Swab on with a Q-tips ⇦this on eBay or Amazon [affil links] until the color matches, wipe off with wet rag.
Robert H Probert
Robert H Probert Technical Services
Garner, North Carolina
Multiple threads merged: please forgive chronology errors :-)
Cadmium brush plating -- Is it allowed on Mil Spec Cad plating?
Q. My name is Shmuel Yankelewitz, and our company ran into a very unique problem recently. We built a Printed Circuit Board for a Military Prime. The board has 4 Military connectors with Cad plating and chromium seal. The plating got corroded (white powder that was analyzed and found to be Cadmium Oxide, When the dust settled we saw specks of bare metal 0.060" dia in a few areas of the connectors and we thought that brush plating can save this very expensive boards. Replacing the connectors is an option with questionable yield. If there is a Mil Spec that allows touch up of Cad plating we can present that to our customer as a better repair option, so after this long background here is my question:
Is Cadmium Brush Plate touch up allowed on Mil Spec. plated parts? If yes, can you tell me what Mil Spec document invokes this plating repair method.
Customer - Norristown, Pennsylvania USA
July 23, 2009
A. The first thing to do is check that your military customer will allow the touch up of the cadmium. If the answer is yes then you can call up MIL-STD-865.
Brian TerryAerospace - Yeovil, Somerset, UK
A. I have done it and it is absolutely no fun. The texture of the plate is different, so it shows and the chromate will be a different color, so it really shows up.
James Watts- Navarre, Florida
July 27, 2009
Q. How can you repair a scratch on cadmium plated part that is an aluminum bronze alloy. Can I brush apply Iridite 80 or use the Iridite 14-2 brush on kit. The part is all clean and painted. Just need to touch up a scratch.
Diana Bevacquaemployee - Chatsworth, California
November 18, 2010
Q. We have some cadmium plated 1200 MPa screws which are of longer length. We want to cut them as per required length and use them. If we go for re-plating then there is a increase in risk of hydrogen embrittlement. If we go for paint, the DFT will be high and the nut may jam. What is the protective coating to be given to the cut face to have similar life as Cadmium plating.
mukesh agrawal- Hyderabad, Telangana, India
September 20, 2018
A. Hi Mukesh. We don't know the application, the spec, or why cadmium plated fasteners are being used ... but you almost surely cannot apply some different type of plating to the cut face without risk of galvanic corrosion, although you could perhaps paint the face without being involved in the threaded area.
If you cannot find fasteners of the right length, the best thing would probably be to send them out for stripping, re-plating, re-baking, and re-chromating though. But for a non-critical application, just leaving the cut face bare might suffice (the cadmium plating will offer some degree of galvanic protection.)
If you read between the lines of Howard I's inquiry and Frank D's reply, you will understand that attempting to chromate bare steel doesn't work. Good luck.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. Thank you for your prompt reply. As you have mentioned, I have already read about SIFCO Cadmium LHE - 5070 Touchup Travel Kit. But the quantity of fasteners are huge and this touch up procedure is laborious. Moreover, I forgot to mention that Cd8 plating is given for corrosion protection of low alloy steel fastener material and also for galvanic corrosion protection of mating Aluminum alloy component. How about using the touch up pens. Please comment.
mukesh agrawal- Hyderabad, Telangana, India
A. Hi Mukesh. I'm not sure if I'm misunderstanding you or you are misunderstanding Howard & Frank and I: the Alodine pens are for touching up the chromate conversion coatings on a cadmium plated surface. You cannot gainfully apply Alodine/chromate to the bare steel of a cut edge.
If the quantity is huge, then it is probably very practical to strip and replate them.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
(Arinc 600 courtesy of TE Connectivity)
Need to touch up Cadmium plate on Arinc 600 connectors
Q. Hello,
My name is Pascale Masson and I'm a mechanical engineer.
During production, the Arinc 600 connectors have been damaged (scratches) and need to be touched up.
The shell of the connector is made in Aluminum per QQ-A-225/8 or QQ-A-591. The finish is cadmium plate per AMSQQP416 class 2 type II yellow with an underplating of electroless nickel per MIL-C-26074
[on DLA].
What can I do to avoid corrosion?
- Montreal Quebec Canada
November 12, 2020
A. Pascale,
1. Usually, AMS specs related to plating do not allow touch-up. However, I do not see a specific touch-up prohibition in AMSQQP416 (please re-check it with the current spec revision).
2. I'm not sure if there is a simple chemical touch-up that will do the job in your situation.
3. Probably you can use some "brush" Cd plating (selective local plating) per AMS2451/4. Chemical solutions are from SIFCO, like "Cadmium No Bake 2023". There is SIFCO procedure how to plate Aluminum surface using Nickel pre-plate.
- Winnipeg, Canada
Q. Hello --
My name is Rob, we are manufacturing some large pins for landing gear shock struts and need to touch up the Titanium Cadmium plate per MIL-STD-865 using the Selectron L.H.E. Process (normal for Hill Air Force Base). As we do not process in-house, we use a local approved processor, we received the parts back and the coating? The coating is absolutely clear?
Question is: Does that sound right? I thought the only touch up color would be more in the dull yellow/gold spectrum. If so, I guess we need to be more specific on our PO.
Thank you in advance for your thoughts and insight.
- Anaheim California
December 18, 2020
A. Hi, I've personally never seen clear chromate being applied on cadmium. That doesn't mean there is no such thing, of course! ... but it does reinforce your concern that something might possibly have gone astray. A call to the plating shop to find out what they are using seems warranted.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Thank you Ted!
I really appreciate your feedback / input.
Have a great 2021!
- Anaheim California
Q. Hello, my name is Sabri Ufuk Arisan. I am a Metallurgical and Materials Engineering student in Middle East Technical University (METU) and currently in the 4th year of my school. I am interested in surface processing on materials, and I am doing research on this subject, but I have a few questions about maintenance for plating.
My questions are, how many times can the same material surface be stripped and re-plated while performing Cd-plating (electroplated) maintenance on 4340 steels? As far as I know, there is a loss of fatigue life on the material after each plating.
In other words, do local repairs (touch-up) or rework have any other negative effects on the mechanical properties? Also, which stripping methods would you recommend for this steel and coating type, chemical or mechanical stripping methods? Finally, in what situations can local repairs (touch-up) be made?
Thank you in advance for your interest.
Student - Ankara/TURKEY
February 28, 2022
A. Hi Sabri. How many times 4340 steel can be stripped and replated is more dependent on how carefully the pretreating and hydrogen embrittlement relief baking is done than how many times it is done -- if done poorly, once is enough to ruin the components. But other things to consider are that there are such processes as LHE cadmium plating (low hydrogen embrittlement), and ti-cad plating (tiny titanium particles in the plating which promote the escape of hydrogen); and there are different hardness grades, with susceptibility to hydrogen embrittlement increasing with the hardness. For the effect of cadmium plating on fatigue strength start with topic 7102 or search the site for "4340 hydrogen".
Another important question is why they are being stripped and replated; if it is because the plating was unsatisfactory, it starts getting likely that pitting is developing and the plating will only get worse with each re-try.
As for the "Stripping of cadmium plating" portion of this question, we have about a dozen threads on the subject. Please start with topic 3212 or search the site for "strip cadmium".
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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