restoration

ken

i have noticed many keys i have bought which appear to have once been heavily corroded (possibly dug items) and obviously restored all seem to have a black finish on them almost like paint. they are usually heavily pitted from years of corrosion but totaly rust free with this black finish on them. can anyone tell me what process is being used to restore these old keys?

2buy1

Ken, Many are probably just painted, but in a former life I worked in an archaeology company. Museum quality preserved ferrous artifacts would go through a 3 step process; 1) electrolytic reduction (to remove rust), 2) immersion in tannic acid or multiple coats of tannic acid (this is when the ferrous material turns black), 3) wax impregnation (to seal from future corrosion). Hope that helps, Jim

Pschiffe

2buy1 wrote
multiple coats of tannic acid (this is when the ferrous material turns black) Jim

One problem with that approach, most cylinder keys are non-ferrous metals. The same would apply to cold black oxide and gun bluing products which only work on steel. There is a commercial acidic solution called Brass Ager, a mixture of phosphoric acid, copper sulfate, muriatic acid and selenium dioxide; which will impart a darkened finish to clean brass.

Pete Schifferli

[unknown]

Dean Nickel

Rust Paint - Rust Proofing Products - Rust Protection - Corrosion Control - Eastwood

There are many things to put on things that are or can rust. Most can be found in the automotive restoration area.

Doug MacQueen

This is an area that I feel deserves its own section. It could include metals used and manufacturing techniques as well. This key was a repair job that came my way last year. It was from a church in Alabama that was still using the hobnail safe which was a bit hard to believe. Note the deep almost black color that the key had naturally acquired. I don’t know if this was wrought iron (almost no carbon),cast iron (very high carbon) or made from steel. I think it was wrought or blacksmiths iron though. Prior to silver soldering it was wire brushed which left it looking much different. I liked the so much I decided to start to make a copy which is shown in the last picture. Doug