Do rusting solutions and/or ferric chloride have any adverse effects on gold inlay material? Thank you.
If you use any of the rusting solns that contain a mercury compound, the mercury will plate onto the gold (or copper, silver, brass..) metal inlays or part when it is applied.
The plating does not just rub off nor does carding remove it.
It has to be polished off which if on an inlay with cut detail can cause problems. It's also difficult to polish an inlay w/o disturbing the surrounding new blue finish.
Not the issue it used to be as Mercury has been pretty much elliminated from the rust blue solns.
It was mostly used in Express Blue solns (Quick Rust). Not so much that I can ever think of in Cold Rust solutions.
The Belgian Blue (Quick Rust) had it in it. Mercury Bichloride I think was the compound.
BirchWood Casey's quick barrel brown for MuzzleLoaders had it as well. That was a great quick rust blue formula.
Even the new Belgian Blue stuff Brownells came out with a few yrs back seemed to have it still.
I tried some of it and it plated out on warmed brass just as the old Herters Belgian Blue did,
B/Casey has since changed the formula to elliminate the mercury bichloride.
No problems with stuff like Mark Lee's Express soln's or Laurel Mtn slow rust. No mercury.
Sometimes the inlays will look a bit dis-colored after rust bluing with these. I think it's a bit of the copper in the copper sulfate in them.
L/M has it in the soln for sure. I think MarkLee does as well.
But that is cleaned up easily enough by going over the inlays with a very soft pink erasure. Doesn't damage the inlay or detail and will polish it nicely just don't over do it.
That discoloration comes right off.
The carding wheel can do some damage to the soft metal inlays. The wire impinges (sp?) into the metal and gives them a frosted look. Only further polishing can correct it and that is difficult
for the same reason as trying to remove mercury plating from them. Flush inlays are very difficult to recover to full brilliance especially fine lines on a finish blued surface.
Also the carding wheel can drag the soft gold and silver from the inlay and onto the surrounding steel surfaces.
Each carding cycle drags a minute amt of gold onto the surrounding steel. You really don't notice it untill the color starts to build. Then the golden halo appears and you are stuck polishing the halo away and starting over.
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Same reason you don't use a wire wheel on brass or copper that is intended for use on steel. It drags the softer metal around and deposits it onto the steel.
I stay away from the inlays with the carding wheel. Go around them with the wheel. Then come back with plain 0000 steel wool or just a piece of clean shot bag matr'l and card them carefully.
Kutter, you are a treasure to this board. My hat's off to you for your generosity in sharing such hard earned experiences, and for doing so in such great, and easy to understand, detail.
Barrels with Gold inlay, that thought can still bring back memories I would sooner not remember. To be honest I have only Browned/Blued a hand full of barrel sets but my first was nearly my last. It was many years in the past now when I first started re finishing guns though later on I found that I was more comfortable with the wooden part of a gun. After applying my usual rust browning/Bluing solution gleaned from Angier's the Gold inlay changed its coat to Silver because of the Mercuric Chloride in the solution... Disaster I thought! Well the Gold did return to normal after some Tooth Paste on a cotton swab, though the gold went back to silver on the next coating of solution. The only thing I could do is to spend a lot of time in the local Library's reference section trawling through through books on G unmaking for an answer. The answer came leaping of the page of a small book written some time in the Early 1900's
It was the practice in his Birmingham workshop to Brown/Blue barrels using the "Hot Box" method and not putting any rusting solution on the barrels at all, he had my full attention. What he described was a wooden box that had the capacity to hold 5 barrel set hung from a rail at the ts at the top, at the bottom of the box was a low wattage electrical heater and a dish of dilute Hydrochloric Acid. The method was simple polish up the barrels keeping away from the gold and the de grease well in fact the recommendation was to ware cotton gloves to keep hands away from the barrel metal. Plug up the bores using rubber bungs hang the barrels in the hot box having firstly wiped them with a goodly amount of distilled water to get things going and do not forget the gloves , rust should start to appear after 12 hours then card with de oiled wire wool. My box was smaller just to hold one barrel set my heater was a 15 Watt bulb the Hydrochloric Acid was the used for brick cleaning about 60% Acid. Continue rusting until you obtain the desired brown or if blue is required boil the barrels i distilled or rain water.
It worked well no rusting solution wiped on the barrels only a rusting vapor with the big plus the Gold was the same after as before though I will say it is slower method of Browning/Bluing though it works well when you become more efficient at it .