Will dissimilar metals in contact cause rust?

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danyboy1899

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I've gotten a Martini Henry where a few parts have been replaced with reproductions made out of a brass-colored metal, a few pins and one screw. There is a bit of corrosion here and there. I'm told it was stored in a case in a place with a bit too much humidity. I'm currently cleaning up the rifle and halting the corrosion using the boiling and carding method.

I'm worried there might be a galvanic reaction happening between the pin and the steel.
The screw and one of the pins are in direct contact with the steel, and at the pin is one of the spots of notable rust, where it secures the handguard to the bottom of the barrel.
I've read that in a dry environment, most metal-to-metal reactions should be minimal to non-existent.
I'm I being paranoid, or should I try to replace these parts with something else?
 
You’re being paranoid. If you’re in a humid area, more routine maintenance is encouraged. If it’s dry, specifically inside where the gun is being stored, it’s of little concern.
 
Galvanic corrosion can only proceed if both materials are immersed in an electrolyte. Keep it dry and oiled, and nothing will happen.

It's probably your only option, as running out to grab some 19th century wrought iron isn't as easy as it sounds. If you use modern steel, you will still have a dissimilar material.
 
I know from working in Potash Refineries - warm moist salty air - likely a good electrolyte - set 3" or 4" deep aluminum cable trays on mid steel support brackets welded to structure - lay on the cables on the trays - within a few weeks, that aluminum would be eaten away half ways or more. Only economical solution we found was to lay a strip of Garlock gasket material - like a rubber sheet - on top of the steel support - no corrosion of the aluminum after that. As mentioned above - dis-similar metals will pass electrons one to the other and degrade - but needs an electrical path - did not look at the chart posted, but well known to chemistry which metals react fastest with which other metals, to promote that galvanic deterioration. From many decades ago, but I am sure that I read that the electron transfer occurs with ANY two differing metals in electrical contact with each other - just some combinations it happens much, much faster than with others - basically what I understand a battery to be.
 
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Ask someone who owns a Land Rover about galvanic reaction.
On a quiet night you can hear the rivets popping off if they have picked up any salt driving in Ontario...
I think they fixed this years ago but the aluminum skin and steel rivets were a real treat.....
 
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