A while back I had some chrome plated brass parts stripped by my local plating shop...They used the 'reverse plating' process but this does involve the use of acid...When I got the parts back I found some of the parts were badly pitted (by the acid) to the extent that a BSA advance/retard lever that I bought from ebay for £28 was beyond saving!!..Grrr!...
Anyway, I now have some more brass parts to strip so I looked up ways to remove chrome from brass components...One method was to soak the parts in industrial Acetone...That, apparrently, removes the chrome but does not remove the underlying nickel which has to be dealt with seperately but is easier to remove...
My question is, does anyone have experience of this Acetone method of removal...I wouldn't mind some practical feedback before going out to by the Acetone....Ian
The pitting in brass is interesting, I have seen brass items recovered from the oceans where the zink has eroded from the structure of the brass due to salt and galvanic electrolosis, it leaves a very brittle frame of copper with voids, which is why a sacrificial block of zink is often attached to ships propellers.
I have a gallon of acetone, I'm not sure if it has the necessary strength or purity but I will try leaving a chromed item in some to see what happens.
I have learnt to nickel, copper and zinc plate components as part of my bike restoration.
I have also had to deal with removing chrome on parts that I don't want chrome on, as it should not be on a WD G3L. That is not a DIY process and I use a local professional plating guy to de-chrome these parts.
I have had a lot of parts de-chromed, including brass and alloy bits. I have never had any pitting issues and it sounds like your guy was over zealous with the current during the process. I would discuss this with him and/or find another plater that knows how to do it properly.
When I worked in electroplating we used to reverse plate to strip the chrome and nickel for parts we were re-plating. This worked for even delicate parts (I once had to replate a set of saxophone keys!). So maybe Ian's platers left the levers in the stripper too long or they accidently electro-etched the brass before putting them in the plating vat (you do this to steel but not brass cos of the zinc content.
In theory, if you strip the chrome and ensure the nickel is sound you should be able to re-plate over this but it was only a fall back.
Try another platers with experience of vintage parts.
Thanks for the replies...
I suspected the fault lay with the plater as I've had many brass parts stripped in the past without problems (by this plater in fact) but wasn't happy with his explanation of the situation when I raised the matter wth him...These parts are too difficult to find to have them f****d up by an incompetent plater so I guess I may having to resort to posting them off to someone else if he isn't admitting to a problem...Ian
