Is your concern with the substrate or with the silver plating?
I've done several types of nickel plating, which is (typically) required as an undercoat for silver, on Invar. A Wood's nickel strike (acid chloride) is used for good bonding to the substrate. A silver strike is used prior to the primary silver electrodeposit.
QQ-S-365D SILVER PLATING, ELECTRODEPOSITED, paragraph 3.4.1, requires > 0.0005" thickness of silver over < 0.0005" nickel for ferrous substrates. This spec. is available at
Please include plating solution compositions with details if you encounter any problems. Normally, the plating chemistry supplier is a good technical info source. Rather than brew-it-yourself, learn using a proprietary bath before switching over to avoid a $teep learning curve.
kenvlach, sbmathias,
Early on we an ass of problems plating Invar. Looking back through some pocket notes and there is almost always a reference to a Cyanide Copper Strike with subsequent Nickel Strike followed by the primaries. In fact we used a local car bumper shop for the Copper and Nickel Plate on all jobs involving any quantity.
I whole heartily second the recommendation to use proprietary plating baths. Even using same there are still a few tricks of the trade have to be ferreted out.
