Cad Plate v Alcohol 2

[Nellysdad]

We cleaned an inkstamp part mark with alcohol and the cad plating came right off, exposing the nickel plating beneath. I was unaware that alcohol would remove cad. Is this just poor plating/poor adhesion?

 

[unclesyd]

Boy! that was some strong alcohol.
The alcohol shouldn't have bothered the plating.
It looks like you have some very bad plating. I would get back with your plater as soon as possible.
Fittings in Breweries were Cd plated at on time.

 

[hacksaw]

cad plate on nickle, why?

 

[metengr]

A strike plate is sometimes used to assure proper adhesion for the final surface plate on a substrate. Certain plating solutions result in poor adhesion because of the reaction between the plating solution and the substrate. A strike plate like nickel or copper is commonly used to provide a thin, smooth buffer surface so that the final plating layer has the necessary adhesion.

 

[yates]

It sounds very much to me that the alcohol did not remove the Cad plate (if it did, why go to great lengths to have complicated solutions to remove cad plate before replating?) but rather removed the yellow color resulting from the bichromate passivation. What you see underneath is the cadmium (silver, metal color). Your parts will not have an underlying nickel strike unless the parts happen to be in stainless steel. Carbon and low-alloy steels do not need any nickel strike under the cadmium.

 

[Nellysdad]

Thankou for your enthusiastic replies. I forgot to mention the parent metal was AlBemet. I want to believe 'Yates' to be nearest to what actually happened....time will tell! If not, then it sounds like there may be a market for this "Alcohol".

 

[metengr]

You had peaked my interest. Doing some research, the AlBeMet is an Al/Be (62% Be and 38% Al) powdered metal alloy. In one of the web sites I had found, the manufacturer of this alloy lists various types of recommended coatings or plating AlBeMet in accordance with military specifications.

AlBeMet uses a nickel strike plate followed by a Cadmium overcoat. I agree with unclesyd's conclusion.