and again . . .
Courtesy Jerrywh I just learned about the Colt book, A Century of Achievement & it is on order.
During this discussion people have mentioned moisture, in association with charcoal. Moisture is formed by burning charcoal that has been charred at a modest temperature, say 700F. Char it too hot and it will form no moisture. If moisture is a problem in your charcoal bluing (I personally have no experience here) it would be less problem to use charcoal left over from annealing, so it has already been heated rather hot.
Ever hear the virtues of good old "moist burning powder"?
Ned Roberts discusses it on pages 81 and 204. "The essentials of a first-class black rifle powder are: First it must be a moist burning powder . . ."
I had no idea what he was talking about. Where on earth could the moisture come from, surely not the charcoal which is simply carbon and ash? Wrong! Years later I learned from Bill Knight & others that it depends upon how hot was the wood in the charring process. Charcoal for black powder contains some creosote, and when it burns it is the creosote that forms some water. Not much, mind you, just enough to make it a "moist burning powder"
I was the Tech guy at a supplier of specialty heat resistant alloys. One day I got a call from South America asking, I believe, if our RA330 was good for his charcoal production. Happens it was ideal. I like to chat, so I asked how hot did they char the wood. I believe he said 350°C, which would be about 660°F.
Oscar Gaddy said something analogous in his color case hardening article, Part 2,1997 published in The Double Gun Journal. He annealed old parts in a stainless steel cylinder filled with granulated charcoal. Did this at 885°C, which is 1625°F. Here he says "If previously unheated wood charcoal is used, as the container reaches a dull red heat color, volatile aromatic hydrocarbons are driven from the wood char coal, and at even higher temperatures these volatile gasses start to burn as they escape from the annealing container. . . Wood charcoal previously heated to this temperature has much superior properties over unheated charcoal when mixed with bone charcoal as a carburizing agent for color case-hardening . . . After the furnace and annealing container have cooled to room temperature, the wood charcoal . . . is stored in an air tight container to prevent the absorption of water vapor . . . for future use."
This is a long way around to say yep, you can get moisture from charcoal. Personally dunno how that would affect the bluing, or whether the charcoal stuck to the steel. That is up to you guys who do this sort of thing.
Earlier someone mentioned using real wood charcoal. Yes, yes, yes, the stuff has to look like chunks of wood turned black. Charcoal briquettes are made with petroleum coke which contains sulfur- because pet coke is cheaper than wood. I know the effect personally, from very careless usage one day, what this can do to a nice smooth steel rod being case-hardened.
OK, I'll shut up now.
