Restore Antique Brass Clock: Remove Orange Discoloration

[mnmclockman]

I'm currently restoring an antique brass clock. In the course of polishing the badly tarnished brass, I have come across some areas of discoloration which do not seem to buff or polish off.

These areas are orange-colored (look like bronze) rather than the yellow brass color of the rest of the piece.. They are not depressed areas of corrosion, but appear to be simply discoloration on the flat surface of the brass.

I have been unable to remove them with polish or buffing, and am wondering if anyone can provide guidance on what they are, and how to remove them.

It is not an option to deeply buff or grind the brass surface, as that would destroy the dimensions of the multiple brass pieces whch assemble into the completed clock.

Thanks in advance. Martin

 

[mgb_phys]

There are sometimes other materials added to brass to make it more corrosion restant especially for marine applications so 'brass' isn't necessarily brass.
If this is an antique clock it could just be that the brass wasn't as carefully controlled as it is now and this is some extra impurity that is forming some sort of oxide layer.

Sorry don't know specifically what it might be or how to get rid of it.

 

[Danger]

Welcome to PF, Mnm.
I would seriously recommend that you not try to get rid of the discolouration. It appears to be an intrinsic aspect of the clock's construction, and thus has historical significance. At least consult an antique specialist before doing anything. If it has any worth as an antiquity, then altering it would destroy that.

edit: Try PMing Hypatia. She's an antique dealer.

 

[mnmclockman]

Thanks very much for your responses. I'll leave the discoloration alone. Martin