Metal finishing Q&As since 1989

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Will plated ABS be watertight?

Q. I am interested in plating ABS plastic but I would like for the part to be water tight after the plating process. If this is possible is there a minimum thickness for the plate?

Thanks

Bob Ryan
- Houston, Texas, USA
January 25, 2012

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In normal thicknesses I would expect any ABS part to always be water tight either plated or un-plated. Is there any particular situation with this material or part design that makes you suspicious?
G. Marrufo

Guillermo Marrufo
Monterrey, NL, Mexico
February 5, 2012

Thanks. I have a complex model with thin (~ 0.5mm) walls that I would like to use at conditions that would not be suitable for ABS. However, I was hoping that by using plating technology I could coat the polymer with a "thin layer" of metal. This then gets back to the question of how thin a layer of metal could be used and still have a water tight system. Once the plating is complete I don't care about the integrity of the ABS.

Bob Ryan
- Houston, Texas, USA
February 8, 2012

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February , 2012

Hi, Bob. What you are doing is often called electroforming rather than electroplating because the plating layer will become the object.

If it's a complex model, your first consideration may end up being the thickness distribution more than the average thickness. It's easy for the plating to be 10x as thick in some areas as in others unless great care is exercised to prevent it (auxiliary anodes, thieves, shields).

Also, internal stresses can become difficult to manage on complex pieces. If you can afford it, gold plating would be ideal since gold is relatively non-porous, and can be ductile and malleable, but sulfamate nickel is perhaps the most common electroforming material. Although I haven't done anything like this, I'd guess that a plating thickness of under 0.001" would be water tight; but mistakes happen, so items that are electroformed of material 10 or 20 times thicker are still helium tested to be sure of their integrity. You might talk to NiCoForm [a finishing.com supporting advertiser] as they have extraordinary experience and knowledge in electroforming, including helium-tight testing. Good luck.

Regards,

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