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With metal finishing, the key is the polish. You can have the best bluing or browning solutions and equipment in the world but if your metal is poorly polished, it will reflect in the bluing/browning.
Polishing entails removal of all the rough marks without removing any stampings (like the make, origin, manufacturer's emblem and what not) from the metal. The easiest way we did it was to replace the wheels on the grinder with one of sisel. A polishing compound (rough) is applied to the wheel and the object held against the lower half of the wheel. Always polish in the same direction so as to avoid any crossing patterns. When it's shiny, then apply a finer polishing compound the other sisel wheel and polish again. When you're finished, set it aside for bluing/browning. Don't touch with your hands since the oils will mar the finish.
If you don't have access to hot blue tanks, you could use the cold rust blue (read instructions on the bottle). I would prefer to do it the old fashion browning technique which takes about three days. Using this technique, you first degrease the polished object (you can dip the frame in a pot of boiling water (tie a wire to the front and back of it so you can suspend it into the pot). After about 10 minutes, pull it out. You want the frame good and hot since it makes any moisture evaporate rapidly. With a clean cotton ball (use rubber gloves since you don't want oil on the metal), dab it with the browning solution and apply an even coat on the metal. When the ball becomes dryish, wet a fresh one and apply. Apply the coat evenly. Now, take the frame and suspend it in a humidifier box (simple wooden box with a 25 watt bulb. Above the bulb in a rack should be a pan of water with a towel). This allows for a high humidity environment which will promote rusting. The frame should be suspended by the same two wires which were used in the dipping process. Let it sit overnight.
The next day, remove the frame from your humidifier box. Using (soapless) steel wool (which must be greasefree), rub off the excess rust. Now, dump it in the boiling water again for 10 minutes and afterwards, repeat the application of the bluing formula. Place back in the humdifier cabinet.
Repeat the above on the third day.
On the forth day, you may want to card off the excess rust. It should be a very dark blue or brown now. Apply a solution of baking soda and water to it to neutralize any further rusting. When it's dry, treat the metal with a paste wax or oil to protect it. Allow it to cure overnight.
You can use store bought Browning agents like Tru-Brown for the above procedure.
A faster way of bluing is to use a rapid browner (like the one Birchwood Casey sells as Plum Brown). You heat the metal to 200 degrees, and with a clean cotton swab, apply the solution. You may have to apply about three coats to get the desired finish and when you're happy, use that baking soda & water mixture to neutralize the browning process. Paste wax/oil follows. Oh, you still have to do that same polishing process beforehand.
Now, if you're lazy, you take it to a gunsmith and pay, pay, pay.
A method which was told to me but which I've never tried was to oven bake it. Yep, just dump it in the over for a few hours (200 degrees) and let the heat color it. Can't testify to the Betty Crocker method or to its durability.
Stelle and Harrison also mention a technique for color case hardening (which I never tried). Take your polished object and pack it into a iron pipe wfilled with fine bone dust. Cap the ends and place it on a fire, allowing it to heat to a red color for fifteen minutes (the thicker the object, the longer the time). Remove the pipe, and dump the object into a pail of cold water (I would use distilled water). For color, Stelle and Harrison recommends using the charcoal of ground up burnt leather in lieu of bone dust.
Next Topic: Brass.
I dislike the dremel. Use files to remove the casting lines and to smoothen the brass. When you're close to finish, use emery paper. Start with a rough grade (120 and progressive work towards a finer grade. You may even take it to the buffer wheel as described above).
Books: Sam Fadala's, "Black Powder Hobby Gunsmithing" is OK for beginners. Walther J. Howe's, "Professional Gunsmithing" has been my favourite for years. Stelle and Harrison's, "The Gunsmith Manual" is very good for old (pre-1900) gunsmithing.
If you have any other questions, please post. By the way, CHEAT. I went to the NRA Gunsmithing College and took their week long course on bluing and parkerizing. You get to use all the machines, bluing tanks, salts, etc. for only $33.
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