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Stannate Plating Process
What is a stannate process? I think it is also know as a 10-step process involving Tin and Cyanide. Who in the U.S. uses this process?
Thanks,
Brandon Hellenbrand- Fairburn, Georgia, USA
First of two simultaneous responses --
Hi, Brandon
The chemical symbol for tin is Sn. Practically, 'stannate' just means alkaline tin electroplating as opposed to acid tin plating (sometimes called stannous sulfate). There might be cyanide somewhere in the overall plating cycle, or in older versions of the stannate process but there need not be. Good luck.
Regards,
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 Ted Mooney, P.E. finishing.com Brick, New Jersey |
Second of two simultaneous responses --
The stannate process is not going to make your aluminum adhesion problems go away.
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Todd Osmolski |
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Let's read about the stannate process:
The Immersion Deposition Process, D.S. Lashmore, Aluminum Finishing Seminar,Vol II, St. Louis, MO, 30 Mar - 1 April, 1982, Aluminum Association, Washington, DC. and Pretreatment for Plating on Aluminum Using The Stannate Process, Jongkind and Seyb, ibid.
Related stuff for tin plating:
Control of Anodes in Alkaline Tin Plating, M&T Chemicals, Rahway, NJ, Technical Data.
Anode maintenance in the Alkaline Stannate Tin Plating Bath,
Lowenheim, Metal & Thermit Corp. New York, NY., reprinted from March 1951 issue of Metal Finishing.
Technical Bulletin, M&T Chemicals, Rahway, NJ, Alkaline Tin Plating with M&T Stannates
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Tom Pullizzi Falls Township, Pennsylvania |
+++++++
Does anyone have a process for speeding up the potassium stannate process using Tin and Potassium Hydroxide?
Mark McCaugheyMetals & Additives - Indianapolis, Indiana, USA
+++++++
Hi, Mark. I originally thought the original inquiry was about a stannate plating process (alkaline tin electroplating) but the responses led me to believe it might instead be about an alternative to zincate for preparing aluminum for electroplating (such as Atotech's Alstan process) -- but it's still not clear to me.
So now I have to ask which topic your stannate inquiry is about? :-)
Regards,
|
 Ted Mooney, P.E. finishing.com Brick, New Jersey |
November 4, 2010
We have a problem with sludge build up in our alkaline tin plating process and are considering a continuous filtering process to remove it. If we do will this:
1) Improve the quality of the plate?
2) Decrease the plating time?
3) Reduce the amount of tin used?
Also an answer as to "why" on all 3 questions would be most appreciated.
carbon brush manufacture - Greenville, South Carolina
November 11, 2010
I am drawn back to Todd Osmolski's comments. Here's my situation.
I used the double zincate system to plate Mid P EN then finish off with rhodium plating on 2024 Al alloy. I have adhesion problem (about 10 %).
I've been told that replacing the first zincate step with an acidic tin immersion coating may help improve the adhesion problem. Or is adhesion problem on alloy 2024 just 'the nature of the beast'.
- Penang, Malaysia
November 11, 2010
If you add an alkaline nickel strike, at near room temperature and then go into the regular EN, I predict that your rejects will drop to a very low number (near zero) The ammonia smell is about the only drawback and the results are fantastic. With one short rinse, the slightly alkaline film of water helps to kick off the EN.
Note, if you do not have a heavy use of the strike, consider adding cooling or you will plate out on the tank during idle periods. It is quite active at temps around 75 F.
- Navarre, Florida
November 16, 2010
Thank you, James. Many commentators of this site are proponents of an alkaline EN strike. Does your statement holds true even if the regular EN is maintained at 1~3 MTO for zincated 2024 ?
SK Cheah- Penang, Malaysia
November 16, 2010
It certainly does. A big reason is that the alkaline EN strike does not eat off any (very little) of the surface of the zincate as the acid EN will do quite rapidly. 1-3 MTO's on EN is very expensive. The strike should allow you to go to 3-6 MTO"s If you can load the EN tank to at least the minimum recommended surface area to be plated. Also, try to always have stuff in the tank as soon as it gets to temperature. Try to get the temperature down as soon as possible after the last part comes out. Cooling is great if you have it. I always saved my last water make-up for when the last part came out of the tank. Bad memory remembers it lowering the temp by 5 - 10F. Lowering the temp by 10F as soon as the last part comes out will probably get you an additional MTO as well as the nitric acid tank stripping is a lot easier.
James Watts- Navarre, Florida
November 17, 2010
James, thank you very much. That's a whole load of valuable information.
SK Cheah- Penang, Malaysia