here ya go...
Submission for "Phillers, Tricks and Tips"
Muzzle Blasts
National Muzzle Loading Rifle Association
William C. Young
January 10, 2000
"Ersatz" Color-casing
When finishing the muzzleloading rifle, one must always decide on just what treatment is in order to give the lock plate, cock, and tigger-bar a nice finished look. There are but three alternatives from which the builder may choose: Leave the metal in the white, brown or blue it, or color-case it, the last one especially apropos for later style percussion pieces, but also oft done to the early Pennsylvania, flintlock rifles.
At this point, I should emphasize certain styles of early flintlock rifles' locks and cocks were oft polished brightly and left in the white state. Sometimes, they were then decorated with a bit of tasteful engraving and varnished to maintain the finish. The frizzens are already heated treated and no additional coloring or finishing, other than polishing, should ever be performed on them. Ergo, even before proceding with any finish on the lock plates, a little research into the appropriate finish is in order.
Conventional, or authentic, color-case hardening is a process requiring specialized apparati, equipment, and knowledge, and such technique is generally not within the scope of the typical home workshop muzzleloading enthusiast. However, if one does not mind a little "poor man's substitute", or ersatz, finish in lieu of the 'real McCoy', here is an easy, but quite satisfying, procedure to have that color-cased look without all the muss n' fuss requisite for the real finish:
Bring the surfaces of the parts up to your expected level of polish by using emery wrapped around a file, no wheels as they tend to round corners and "saucer" holes. After cleansing of all grease or oils, lay the parts on a firebrick, heavy sheet metal, or any non-flamable surface. Using an oxyacetylene or oxypropane torch, the latter is actually preferred, with a small orifice tip installed and gas and oxygen pressures turned down quite low, but with a small, intense flame, come down on the surface of the metal and make random motions or 'squiggles' with wavy movements, and note the temper colors of the polished metal appear in these small splotches or areas. Do not stay on one area long as it will soon become too warm, and the colors will be lost. Move the torch to a more distant area of the part. Once you have created this patchwork of blotches of temper colors, allow the part to cool to a point well below the sizzling temp of water, but too warm to comfortably handle. Using a fresh Q-tip or the like, apply a coat of cold blueing, such as Birchwood-Casey's Perma-Blue, or similar product, over the entire piece, and be generous in this application. Next, allow the piece to cool to almost ambient temperature, then rinse in clear water, dry it off, and lightly buff it with #0000 steel wool into which you have soaked some oil. The colors should now have a pleasant, deepened contrast. At this point, if you desire, you may clean up the blue coloration with emery on the inside of the lock plate. Also, now check the plate for straightness, as sometimes, due to differential thickness around bolster area, the plate will warp a bit from the heat. If this is the case, merely clamp in vise with soft-jaws and restraighten the plate. Before reintroducing it into its mortise, allow the part to "cure" for some time, maybe, while you have lunch or take a break.
Be sure when doing the heating and applying the blueing reagent, you do not touch the metal with your bare hands as your fingerprints will surely become obvious! Also, parts like a percussion or flint cock will require a bit longer heating time, or even little more intense flame, due to their greater thickness.
You may wish to practice this technique on some polished scrap metal before actually doing your lockplate, but this finish may easily be emeried back off and redone to your satisfaction. Although not as a tough as rust-blued or rust-browned finish, it is surprisingly durable and will withstand most normal handling and use.
We were able to turn back the clock, we might see that many muzzleloading rifles' lock plates were in fact often not browned, but colored by various means, or simply left white. The brown patina appearance we now see on original guns is generally the result of many years of weathering and handling.