Where the
world gathers for metal finishing
Q&As since 1989


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Magnetic chrome?

received a query from a boat builder about chroming bronze or brass compass binnacles.
He'd heard of it affecting the compass performance by disrupting its field.
I'd never heard of such a thing, nickel and chrome being non magnetic, I didn't see how it could.
I've plated many with never a complaint.
He then gave the name of a reputable plater who had assured him he had encountered, but knew how to deal with the problem.
Is somebody taking this guy for a fool, or is there something I should know?

Steve Clark
polishing shop - Belfast, Maine, USA
2006

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One thing you should know is that nickel is ferromagnetic - that is, it is attracted to a magnet in the same way that iron is attracted.

Whether there is enough nickel plated onto a compass binnacle to affect the compass operation, or whether geometrical symmetry of the plated areas encircling the compass self-cancels any interference, is a matter for experiment (either your experiment, or the results of any previous work done by others).

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
2006

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I appreciate that nickel is ferromagnetic, but I have never found it sufficient to throw a compass off.
I also know that given sufficient heat the field stops only to return on cooling.
I was surprised that it had been considered a problem in the first place,and secondly that there was supposedly a way to eliminate it, or prevent it occurring.
By the same token I would not like to think of a boat on the rocks because I plated his binnacle cover.
Being on the Maine coast. I get them quite regularly.

Steve Clark
polishing shop - Belfast, Maine
2006