Dicropan IM - How Many Guns to the Quart?

[321BMT]

Does anyone know how many handguns you can blue with a quart of Dicropan IM? Model 10's, Star BM's, or similar sized.

[Der Gebirgsjager]

I'll try to give you an answer, but it's probably not the best one you could wish for. First, believe it or not, I've got a qt. of Dicropan sitting on a shelf in my shop. I've never used it, and it's about 15 years old, so maybe needs to be disposed of. Dicropan is Brownell's answer to the old Belgian Blue process, and supposedly works the same way-- somewhat, anyway. I had plenty of experience with Belgian Bluing, and liked the process and results. I used it almost exclusively on old shotguns that were doubles with soldered joints or soldered ribs. The process uses a hot water tank, but it doesn't get hot enough to melt the solder. So, what you did after preparing the metal, was to immerse the work in the hot tank until it was the same temperature as the water, remove it and quickly paint it with the bluing solution. The bluing solution was diluted with water, contained in a glass jar, and suspended over the edge of the tank into the water to make the solution hot as well. Once the solution was applied the work was dunked into a cold water tank where it remained for a few minutes until it was cold and rusted. The work was removed from the cold tank and carded with 4-0 steel wool. The process was then repeated until the desired shade of blue was achieved. It usually took a minimum of 3 applications and often 6 to get a good job.

So, assuming that the Dicropan process works the same way, it is difficult to give you an exact answer as to how many handguns you can blue with a quart. It will likely depend on the number of applications needed. It will also depend on if the Dicropan must be diluted making how much solution, and if any leftover solution is reusable, which is was not with the Belgian process.

My opinion is that Dicropan would not be the best way to go for handguns. If you don't want to get involved with the hot salts bluing process, then one of the many slow rusting products on the market would likely be the way to go. If you are thinking about re-bluing the surplus handguns presently available on the market as a commercial enterprise, I would stay away from it unless I had buffers and a hot salts bluing setup. If you want to re-blue a representative sample or two for your personal collection, then I'd go the slow rust bluing route.
Be aware that, generally speaking, the level to which you prepare the metal, as an example to a 400 grit finish, will appear as at least one grit level (and maybe two) lower on a rust blued piece such as 320 or 220.

[William Yanda]

"400 grit finish, will appear as at least one grit level (and maybe two) lower on a rust blued piece such as 320 or 220."
D. G.

Are you telling us the process magnifies/highlights imperfections in the mechanical finish?
Thanks
Bill

[Der Gebirgsjager]

No, a rust blue (or Belgian Blue) finish etches the metal's surface a bit. Put another way, what happens when metal rusts? Part of the metal's surface is oxidized and when it is removed there are tiny pits. Metal finishing is a series of finer and finer scratches, 220 grit being erased by 320 grit erased by 400 grit, etc. all the way to a mirror-like 1200 grit. It reflects light and appears shiny(er) as the surface becomes smoother. Etching microscopic pits into the surface by rusting gives less light reflection and appears duller.

To exactly answer your question the way it was put, yes, imperfections will always be highlighted by bluing. The most important part of any bluing process is the best possible metal preparation. Not so much with the modern coatings, as paint tends to flow into and fill imperfections.

[Der Gebirgsjager]

The O.P. has not as yet responded, and we do not know what he has in mind, but let me say that in my mind, experience, and taste nothing approaches a properly done hot salts bluing job. But, I also want to make it clear that hot bluing as we know it came on the scene long after rust bluing. All of the fine European military weapons like Luger and Mauser pistols, and Mauser rifles and their predecessors were rust blued. In fact, as an aside, if you ever decided to acquire a Mauser M1896 (broom handle) pistol, the way to determine if it has been refinished or not is to completely disassemble it and look at the interior. For some reason the factory didn't think it necessary to blue the inside of the frame/magazine well, and did a sloppy job in applying the rust bluing solution. If the finish is original, you will see runs and streaks inside the frame, whereas if it's been re-blued those areas will be a uniform blue like the exterior of the pistol.

All bluing techniques have their place in gun work, but require differing amounts of equipment and financial outlay. Although during my gunsmithing career, now some 10 years ended, I was a general gunsmith, but I specialized in re-bluing. You have to match the finish to the firearm, unless the customer wants something else. A consideration is "what was the original finish of this firearm" so that it doesn't look
very out of place. A highly polished, hot blued Luger pistol is definitely immediately recognizable as a re-blue. I've been keeping track of the surplus market, and the pistols mentioned by the O.P. are what is currently offered. S&W Mod. 10s, Star BMs, and most recently Beretta M1951 pistols. Disregarding the fact that the M1951 has an aluminum frame and would best be painted, all of them would look quite good with a well done rust blue, which would require only a small humidity cabinet, easily homemade. But, all of them were originally hot blued, which would require a financial outlay of $2,000 to get into the business. So, that reflects on my original answer inquiring what the O.P.'s intentions are.

[Remiel]

This was very informative, either way the op decides there is a good amount of information in this.

Sent from my SM-G970U using Tapatalk

[321BMT]

Thanks for your replies. I do intend it for personal weapons. The price for a good hot salts job on these guns is just prohibitive. Years ago I had a couple of friends who had small bluing operations. They let me prep and blue my own guns, and I know how to get them ready. I did a Dicropan job on a Ted Williams 101 that came out very well, but it was a lot of work. I was just wondering how many guns I could get from a quart since a quart is about $90 with hazmat and shipping.

I found a company on line called Glenrock Blue that will dip your prepared revolver for $95.00. That's pretty reasonable. It would be the same prep I did for a home blue. Has anyone used these guys?

[waksupi]

Why not rust blue? Very cheep to do.

[321BMT]

You guys have a lot of experience in bluing so this may sound dumb, but I can't really find an answer. All the prep instruction I find ends with putting the parts in boiling water and then straight to the bluing tanks. What if you have several guns to polish and prep or if you can't get all the way finished with the parts of one gun. How long can you wait between prep and bluing? Do you need to oil everything and come back later? I'm looking to do my own small projects, but I may not be able to put in more than an hour or two at a time. I know as soon as I stop polishing the rust starts again.

[Der Gebirgsjager]

The answer to your question, depends on your equipment. If your metal is prepped to the level you desire but you can't blue them immediately, there is a spray on product called "Hold" available from Brownell's. Also, yes, you can oil the parts to keep them from rusting until you're able to put them in the tank. When I found it necessary to do that I used kerosene. The best thing to do in that circumstance is to then remove the oil with a solvent before putting the parts into the hot tank, but I've sometimes put them directly in to a cleaning tank. My set up had (1) a hot tank with a cleaner in the water, (2) a cold rinse tank, (3) the bluing tank, (4) a hot boil out tank. Then, there was a tank filled with water displacing oil into which the parts were dunked and left for a few minutes, but I've also seen them sprayed with WD-40 or squirted with Corvis Oil. I don't know where you live or what the climactic conditions are, but unless it's very humid your parts aren't likely to rust up if left unprotected short of overnight. If I was starting to polish in the morning and planning to blue in the afternoon I wouldn't consider oiling the parts to be necessary.

[321BMT]

I live in the South so humidity is always high. I was thinking more like polishing this weekend and having to wait until next weekend to blue. The only guns will be handguns so I'll be using big pots instead of tanks, but I can set up multiple pots.

[Der Gebirgsjager]

Well then, given that information, I would use a preservative on the parts. Just be sure to degrease/clean them well before bluing. Bluing tanks are usually made of black iron, some of stainless steel. I imagine that a cast iron pot would work, but do not use a pot that has been coated or plated as the surface substance will likely plate onto your work. Do not use a pot that has any other metal than ferrous (i.e. iron, steel) such as copper or aluminum as the bluing salts will dissolve those metals. Do not put any non-ferrous metals into the bluing salts or they will kill the salts and again adhere to the work, and dissolve the parts. Hot salts bluing really isn't a mystery, but it's best to follow the system and sequence outlined in Post #10 (above). The salts are hot and corrosive, and will injure you if splashed onto your skin or into your eyes. By all means wear heavy rubber gloves, a long sleeved shirt, and safety glasses. A remedy to contact with the salts on your skin is cheap, white vinegar-- keep a bottle handy.

[321BMT]

I've been pricing the chemicals to do one of the DIY recipe's, and that stuff is not cheap. Enough to make up a gallon will over $50.00. With the rest of the stuff it's gonna mount up. That $95 price from Glenrock Blue is looking good. Has anyone had any experience with their work?