Suggestions and tips for a small in house plating plant. 1

[Madness42]

Hi there.

I work for a small machine building company. We have electroplating done from time time, mainly for anti rust and decorative reasons.

I would like to build a small plant for a bright finish. Either bright zinc or nickel.

It can either be electro or nonelectro.

What are the easiest and cheapest options available?

Many Thanks
Madness

 

[swall]

I wouldn't want to discourage you, but there technical implications of keeping the process in control. You may need a small lab and a part time technician. Depends on how critical your work is. There are also waste disposal issues to deal with.

 

[FinishingTalkdotcom]

There is too much info to list on this reply. I would recommend contacting a consultant for help with this installation. You can find one at

http://www.finishing.com.

They can walk you through the environmental issues (air and waste water), technical analysis of all plating solutions, and line set-up. If the capital expense is too excessive, I would recommend contacting some of the jobshops listed on this site for quotes. There is a place called Scovill in Clarkesville, GA that does high quality plating, oxiding, antiquing, and many other finishes, and are very competetively priced. Just send an email to value@scovill.com.
Hope this helps!

 

[Madness42]

Thanks Swall

Well... I will be the part time technician. And a small lab may be an option. We have a good plating supplier, but turn around time is very critical.

Also. It does not need to run every day. Probably once or twice a week. The rest of the time it can be running idle (if possible).

I realise I may be walking into a world of pain, but that is kinda my job description here. So please any more info would be really appreciated.

P.S. I have had a look at finishing.com. It is a wealth of info, will take me some time to find what I am looking for.

 

[FinishingTalkdotcom]

Feel free to check out our site as well.

http://www.finishingtalk.com

It is full of members with years of experience eager to answer questions relating to plating and finishing.

 

[kenvlach]

For info on electroplating nickel, see
Ni coating of steel from a Ni-solution
thread332-177843

For metal finishing books:

http://www.finishing.com/Books/index.html

Products Finishing magazine's on-line site is very good (many archived articles):

http://www.pfonline.com/

Their 'Plating Zone' is aa good place to start:

http://www.pfonline.com/plate/index.html

Metal Finishing magazine is also good, but some access is limited to subscribers. Also have a free email newletter:

http://www.metalfinishing.com/

Many solutions need to be heated, so may not be cost effective if only operating 2 or 3 times/week. E.g., electroless nickel usually operates at 90^oC.

Sulfamate nickel, an electrolytic type often used because it produces low residual stress deposits, operates at about 50-55^oC and uses boric acid which precipitates out of solution when cooled (bad for filters, so have to go through extra procedures every cool down & heat up cycle.

Wood's nickel solution (used as a strike coating on steel, stainless steel, titanium, etc.) operates at room temperature but has a different problem: The high hydrochloric acid concentration keeps dissolving nickel anodes even when not plating, so need to remove the anodes when not in use [or replace them with plating grade (non-porous) graphite electrodes].

Probably best to get a turnkey plating line from one of the maor plating chemical suppliers (otherwise, the chemical supplier will blame the equipment supplier & vice versa).

You will also need to provide secondary containment, a de-ionized water supply, ventilation.
If doing zinc, also need a chromate process that is compatible with the specific electrolytic zinc -- get the chemistry from same supplier.
Also, need wastewater treatment for the metals.

 

[Madness42]

Thanks kenvlach.

Great starting point for me. Woods strike method sounds good. Removing the nickel anodes will not be a problem.
We can just put the anodes in when we need to run it.
Also I like the benefit of room temperature.

The first tank I think will be quite small. I am thinking 500x200x300.

This is just the beginning of what may be a long term project. Will keep you all posted as to how it goes.

Madness

 

[kenvlach]

A strike plating is an extremely thin plating that prepares difficult-to-plate metals for the principal plating. It also protects expensive electroless nickel & proprietary bright nickel solutions from contamination by other metals.

Proprietary solutions are available for matte, semi-bright, bright, and satin finishes. These also contain leveling and anti-pitting agents. While the Wood's nickel is a very simple DIY solution, and sulfamate nickel as used for very thick plating (electroforming) can also be so, I wouldn't recommend bright nickel plating from a DIY bath (at least, w/o a few years of expertise at the chemistry involved).

There are also versions for duplex layer nickel plating, as often done prior to bright chrome plating, in which the layers have different galvanic potentials to minimize pitting corrosion.

 

[Madness42]

Then what would you suggest? Zinc?

Also I realised that I should mention we are only going to be plating steel as a start.

 

[kenvlach]

Use Wood's nickel, but it's only a thin underplating (& a very good one) which is followed by plating with the desired bright or ductile electrolytic nickel or electroless nickel.

If you wish to do zinc plating, there are 3 categories of plating solutions:
Acid zinc,
Alkaline zinc,
Cyanide zinc.
Unfortunately, the least environmentally friendly cyanide process works best. A more complex wastewater treatment is necessary.

There are also 3+ basic categories of chromating for zinc:
Bright blue
Yellow,
Black (more expensive, may use silver)
Other colors are available by dyeing the chromate.
Complicating things is the switch from well-known hexavalent chromate (Cr+6) solutions to trivalent chromates (Cr+3). Fewer color choices, not as corrosion resistant, but an organic sealer is often available as a topcoat from the chromate chemistry supplier.

Also becoming more popular is the plating of zinc alloys (Zn-Fe, Zn-Ni, Zn-Sn, etc.) rather than plain zinc. The alloys usually have better corrosion resistance & abrasion resistance, and as long as at least 85090% Zn can still apply chromate.

You will have to locate the available vendors in your country. Some global suppliers are Atotech, Chemetall, Enthone (Cookson Electronics), MacDermid, OMG, SurTec & Uyemura. They should be able to supply the necessary chemicals & equipment & provide technical support (important for start-ups!).