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Material Choice for Anodes & Auxiliary Anodes in Nickel Plating?




Q. I have just plated 19" alloy wheel by using Platinized Titanium auxiliary anodes in both semi-bright and bright nickel. After plating finished I found much particulate on shelf (horizontal) area. I am sure that there was not any particle in the nickel bath before because I cleaned the solution and tested by plated 4 wheels in nickel tank without auxiliary anode which I did not see any particles on all wheels.

I have heard that [company name deleted by editor] in Canada have also used platinized Titanium as auxiliary anode for their wheel plating. Is it true?

Does PT/Ti make particles in nickel bath?
What other kind of metal can I use in nickel bath without any problems?

Aon Dum
- Bangkok, Thailand
2007


A. Hello, Aon. (Sorry, we deleted the name of the plating shop you mentioned; they may consider it a trade secret and inappropriate for us to tell the world what they use for auxiliary anodes). A number of shops use platinized titanium auxiliary anodes, and I don't think it's a problem. I personally don't think the platinized anodes are the source of the shelf roughness.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007



A. Aon,
Just a quick note to add. If you suspect the Pt is peeling from the Ti substrate, take a portable propane torch and heat the anode for one minute, keeping the flame in one spot. If the anode turns black after wiping away any smut, there is very little or no platinum on the surface. If it remains a silver grey color you have sufficient Pt thickness. I prefer platinum "clad" Ti or niobium. The term "platinized" can mean the anode material is electroplated with as low as 10 microinches Pt thickness. Does your anode supplier provide certs regarding material type, lot # and thicknesses? It is important to know.

Mark Baker
Process Engineer - Syracuse, New York
2007



A. I am in perfect agreement with Ted Mooney, but want to add a couple "way-out" possibilities.

With high voltage in the presence of chloride, the platinum will be undercut and fall off, but probably would not settle on the shelves.

If the boric acid is too high for the temperature, then the boric acid will fall out on the shelves, and this is a very common cause of shelf roughness.

robert probert
Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina
probertbanner
2007



A. Nont,
Did you platinize the titanium after fabrication? Maybe there are welds that are not platinized?

Rob Coffie
Warren, Michigan, USA
2007



2007

thumbs up signThank you so much for your ideas.

Q. How can I measure platinum thickness? Can I use Ir/Ti mesh or Ru-Ir/Ti mesh to be auxiliary anode in nickel or acid copper bath? Is it source of any problems if I use it?

Is there any devices or tools that can do this work? Where can I buy it from?

Thank you for taking time with my question.

Nont D.
- Bangkok, Thailand


A. Hello Nont D. I am working for a company which produces titanium anodes. You can use Ir/Ti mesh or Ru-Ir/Ti mesh to be auxiliary anode in nickel or acid copper bath. But if you use Ir-Ta/Ti mesh, the life of the anode will be longer, and electrolytic effect will be better. About the platinum thickness, there is no device or tool can do this work in our country. You can turn to some other countries.

Ying Liu
- Baoji Shannxi China
May 17, 2011




Multiple threads were merged: please forgive repetition, chronology errors, or disrespect towards other postings [they weren't on the same page] :-)



Dimensionally Stable Anodes

Q. I would like to learn more about Dimensionally stable anodes (DSA). I am considering purchasing one for an experiment. But I still do not know much about them. Could you give me any general information about what they are and what their benefits and shortcomings might be if compared to other types of electrodes?

Thank you.

James Patrick McKinney
University of Florida - Gainesville, Florida, USA
2006


A. Hi James. For an electroplating process to take place, metal must deposit on the cathode. This metal can come from either one of two places: it can come from consumable (soluble) anodes made of the material that you are trying to plate; or it can be dissolved into the make-up solution, in which case you use non-consumable or DSA anodes whose purpose is to act as an electrode not as the supply of metal.

It is usually best to use consumable anodes because they will be an inexpensive source of the metal, and it's usually easier to keep the solution in balance because metal is dissolving into it in almost exact measure to the metal being plated out of it. But there are cases where consumable anodes cannot work for electrochemical reasons (chrome plating, for example), or where they would be prohibitively expensive (no one can afford to have hundreds of pounds of gold anodes sitting in a gold plating tank), or where a combination is best (the nickel plating step in chrome plated wheels, where soluble consumable anodes supply the nickel but DSA auxiliary anodes may be used to get an electrode deep into recessed areas).

DSA anodes can be platinum clad titanium, but there are several other choices discussed above.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006




Multiple threads were merged: please forgive repetition, chronology errors, or disrespect towards other postings [they weren't on the same page] :-)



Can Nickel 200 be Used as Anodes or as an Auxiliary Anode in Nickel Sulfamate Bath?

Q. Can Nickel 200 be used as a substitute for Oval Depolarized Anodes or as an auxiliary anode in a Nickel Sulfamate bath? We used to buy 1" round depolarized bars from a company in England (ten years ago) that is no longer in business and I am not able to find a supplier here in the US. thanks,

John George
plater - Troy, Michigan
July 12, 2011


A. Hi, John.

As far as I can envision there would rarely be a need for auxiliary anodes to dissolve, so I don't see why Nickel 200 could not be used for the auxiliary anodes. But I think you will need depolarized nickel for your main anodes in order to reliably dissolve nickel into your bath for the plating to reliably continue. If you can't obtain it as oval bars anymore, I think you'll need to switch to anode baskets and S-rounds or similar. Good luck, and maybe you'll get a more encouraging second opinion.

Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
July 13 2011


A. Nickel 200 is 99% nickel, so it would not be a bad metal to uses as an auxiliary anode if the total area was a fairly small % of the total anode area. Since it is not very soluble compared to S rounds, it is going to affect the internal stress of your nickel plate. We used it to keep the internal stress in the desired range as well as it filled a need on certain parts. Excessive use is as bad as not enough.
You could use micromesh Ti baskets with SD nickel pellets. I used them in a 1" dia. basket, covered with napped poly "socks".

James Watts
- Navarre, Florida
July 13, 2011




April 10, 2014

Q. We are getting ready to electroplate internal bores with our nickel sulfamate process.
We continually do narrow through bore without needing auxiliary anode through rods.
these new parts however are plated internally on one end approx. 5" down into the bore.
the bore diameter is approx. 1.490.
would just a stainless steel rod do as the anode or does it need to be nickel also?
I'm having trouble located nickel rod anodes or any bars to machine to rods.
Thanks,

Sherrill Connell
Quality Manager - Monroe, North Carolina, USA


A. Hello Sherrill,
You may have better luck finding titanium rods or platinum clad titanium for your auxiliary anodes. I would not use SS anodes. One thing to keep in mind is that good cathode agitation that will "push" solution into the holes, thereby supplying fresh Ni ions inside the holes at a good rate. Front to back cathode rocker agitation works well in conjunction with eductors on your filter system discharge lines. Good Luck!

Mark Baker
process engineer - Malone, New York
April 21, 2014




Q. Thanks Mark.

I've located essentially pure titanium 1/2" diameter rod. Would this be okay for my auxiliary anode or is there a titanium alloy that I should be looking at?

You mentioned rocker agitation. We've been wondering whether to try and plate bores vertical or horizontal.

Sherrill Connell [returning]
Quality Manager - Monroe, North Carolina, USA
April 21, 2014



simultaneous replies

A. Hi Sherrill,
There appears to be some confusion here. You certainly cannot use titanium as an auxiliary anode. It will immediately become passive and will not conduct current to the electrolyte. The titanium must first be platinized before you can use it.

harry_parkes
Harry Parkes
- Birmingham, UK
April 23, 2014


A. I would NOT use a Ti aux. anode. This will plate Ni out of solution and your stress will go compressive if it is anything more than a couple of percent of the total area being plated.
Ti will sometimes passivate and you could get some strange plating patterns.
Ti will corrode at higher voltages.
I would use nickel 200 or 400 rods for your aux. anode. Remember to wrap them with a similar material to your main anodes or a napped polypropylene cloth.
Is this an open or closed bore??

James Watts
- Navarre, Florida
April 23, 2014


thumbs up signThanks all!
My bore will be open. Entire bore is approx. 9" with a flare to slightly larger about half way through which I will mask. The nickel plated area will be approx. 5" long from one end. And the Bore approx. 1.5" Diameter.

Sherrill Connell [returning]
Quality Manager - Monroe, North Carolina, USA
April 24, 2014


A. Are you plating other portions of the part at the same time? If so, you would have better plating if you used a second power supply for the Aux. anode since your anode to cathode distance will be much tighter.
Very good air agitation under the bores will go a long way to getting uniform plating.

James Watts
- Navarre, Florida
April 24, 2014



Q. The internal bore is the only surface that will be nickel plated. We have air agitation near the bottom of the tank. It's only a 30 gallon tank with 15" of solution right now, but we're getting ready to go to a 60 gallon tank with approx. 20" of solution. Still, air agitation from an oilless compressor.

Sherrill Connell [returning]
Quality Manager - Monroe, North Carolina, USA
April 25, 2014




Dimensionally Stable Anodes for Nickel plating

May 11, 2015

Q. Hello,
I confronted with a problem to solve and I found no solution so far.
We have to plate a pipe section 70 mm long and 45 mm in diameter.
The challenge is that we need to stay in a very narrow thickness range.
Outside no more than 15 µm at least 4.5 µm at the inside of the pipe.
After a few tests we switched the project to a setup with internal DSA.
My question is now what material can I use for the DSA ?

Here some facts:
-360 pcs per rack
- max. daily capacity more than 10.000 pcs.
- we will either use a Watts or a Sulfamate Nickel depending on the test results by our customer
- all DSA will be mounted on the racks and will go thru the complete pretreatment every cycle

Any suggestions for this?

Thanks..

Mike

Mike Immel
project manager - Dillenburg, HE Europe




Gold in lieu of Platinum for DSA/Auxiliary Anodes?

Q. Does anyone know why gold anodes can't be used for general purpose electrochemistry in aqueous solutions (free of halogens) without some oxidation, unlike platinum? I know that Pt passivates, but in view of the fact that gold oxides have a positive heat of formation and free energy with respect to diatomic oxygen (and I believe gold is the only metal with no thermodynamically stable oxides) why is it that once anodic oxygen (which I take to be monatomic) forms an oxide monolayer, additional oxygen does not preferentially react with the oxygen in the oxide, reducing the oxide back to gold in much the same way that hydrogen peroxide can reduce oxides of gold and silver? It seems to me that no visible oxide layer should ever form on gold anodes, yet I observe (and read) that it does.

Ansel Wald
general chemistry - Bothell, Washington USA
September 22, 2015


A. Greetings,
The main reason that Au anodes are not used is because of the theft risk factor. As you know Pt anodes have very low resistance qualities. With most Au solutions, current efficiency runs between 40 and 50%, so it makes more sense to use Pt. In acid or neutral gold plating, Pt anodes are the norm in the industry.

Mark Baker
Process Engineer - Phoenix, Arizona USA
October 10, 2015




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