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Discussion Starter #1 (Edited)
Bluing on Japanese rifles

Topic:
Topic author: Stan Zielinski
Subject: Bluing on Japanese rifles
Posted on: 11/25/2003 3:54:29 PM
Message:
Some time back there was a thread on some one trying to re-duplicate the bluing on Japanese rifles. Can anyone provide an update?

Replies:

Reply author: JWMWITZ
Replied on: 11/26/2003 6:13:14 PM
Message:
Stan,

That was me; I'm a chemistry guy, and figured I could match up the bluing process since I dabble in gun-smithing. I got a hold of several old formulas for rust bluing (an old gun bluing book; can't recall the name but I'll post it if you want) and had a lot of trouble making them work.

I reblued an entire Type 38 that I bought for $10 using Van's instant gun blue. It came out suprisingly well. The rifle was a complete disaster when I got it; totally covered in rust, mismatched, ground. The stock was aweful, but after cleaning, it had some really cool Japanese numbers in the stock (it was a school marked rifle). I refinished the stock using Urushi that I bought when stationed in Japan, and it came out great. The bluing is a little blacker than the original finish however. It looks nice hanging over the fireplace.

When I tried the various gun blue formulas, I had much difficulty getting all the parts to come out exactly the same. I don't know if this was because of different types of steel, or temperatures, or poor cleaning of the parts on my part. I tried to control as much as I could (I'm a chemist after all). But, I am somewhat equipment challenged. I do not have the heated tanks and so forth for rust bluing. Some of the parts came out pretty nice, and others were duds. Maintaining a constant temperature was a problem, as well as "scratching" the parts. I wasn't quite sure what that meant. Anyway, I didn't have much luck matching up the early type 38 rifle bluing.

If I were to reblue say a buggered screw that I had filed down, I'd use Van's Instant. Be sure to oil it down right after taking it out of the bluing salts; this neutralizes the acidity. They come out very close to the original color.

John in Charlotte, NC



Reply author: rcb
Replied on: 11/26/2003 7:08:51 PM
Message:
Where might one find Van's Blue. rcb.
http://www.rb-treasures.com/MPI_Products/VanBlue.html
Here is the answer to my question.

Reply author: Ronin48
Replied on: 11/27/2003 08:41:44 AM
Message:
Stan, Years ago had a two digit SN 30 carbine some baca had sporterized the stock. Metal appeared to be original as was the finish. Blue was a 'robin's egg' blue rather than the dark blue we are use to. Another one I wish I had held on to! Ubman

Reply author: fredh
Replied on: 11/28/2003 08:47:59 AM
Message:
John, some of this is a repeat from the previous thread. Did some blueing when I was a kid and found Van's to be the best of the lot. That's not saying much since I ran into the same problem as you - inconsistent results. An 1848 Springfield and other early Springfields came out brown; parts on Japanese rifles varied according to steel and heat treat from blue-brown to pretty good blue. Most recently, I've had consistent success with Birchwood Casey Perma Blue. Gives a blue-black color similar to say a Toyo Kogyo long rifle. Stan, I've got the blueing formula for Nambu factory, and I think they got it from Koishikawa. That will take some digging and will try to find it. It's in correspondence from Japan. I was told the Japanese switched to hot salts blueing with introduction of the Type 99. They had been using rust blue. Don't know if the switch went across the board, but was told hot salts blueing was what everyone was going to in the late 30's since it was expedient. For those who have a nice early Type 38 and Toyo Kogyo Type 99 long rifle, take them out in the sun. You'll see the difference immediately. John, you're talking about Angier's book. "Scratching" is wire brushing or rubbing with steel wool the blued surface after rusting. I tried getting some of those formulas made up when I was a kid but was told by a pharmacist that some of the compounds are no longer available as specified in the book. You know more about this than I do, but that would be a reason for bad results.

Reply author: kfields
Replied on: 11/28/2003 4:50:09 PM
Message:
I've been curious about the bluing on the different manufacturers of T99's. Among those in my collection, the Nagoya's and Toyo's appear more of a flat black whereas the Kokura's appear to have a brighter blued finish. Is it just my eyeballs or is there a real difference?

Reply author: fredh
Replied on: 11/28/2003 8:41:22 PM
Message:
That difference between T99 manufacturers is what makes me think not everyone changed over. As the war progressed, the different arsenals were not as careful with temperature control, so variations in blue shade occurred, everything from black to gray to blue to thin blue. Then surface finish affects reflection and shade also.

Reply author: Stan Zielinski
Replied on: 12/01/2003 12:15:06 PM
Message:
Fred, I would very much like to have a copy of that formula, both Japanese and English.

John, could you tell me which formulas from Anger's book you tried? You can e-mail me offline if you think the answers would take up too much space here.

I recently acquired a bunch of Japanese rifle parts including barrels and several incomplete rifles. I would like to do a little research on the bluing techniques used by the Japanese.

Reply author: Earl
Replied on: 12/01/2003 2:12:53 PM
Message:
There is also differences within a manufacturer...look at Kokura 25th series Type 99s for instance...they have the widest range of finishes that I can recall in any given series/arsenal....blue, thin blue, black blue, no blue...very interesting series as far as metal finish goes - and the beaver chatter stocks are a nice touch too.

Earl

Reply author: Stan Zielinski
Replied on: 12/01/2003 7:02:49 PM
Message:
I suspect the variation in Japanese bluing on the Model 99 involved lack of appropriate quality chemicals as well as skill of personnel doing the bluing.

I have Clyde Baker's book on gunsmithing which describes his method(s) of bluing. As this book was originally written in the '30's (not sure of original date of writing) it should be more in tune with the techniques of the times. Baker's method of bluing small parts like screws was to heat the screw to a dull red, immerse immediately in a solution (forgot proportions) of linseed oil and Marble's Nitro Solvent, remove almost immediately and then immerse until cool. (I think I have the sequence correct; I'll check to be sure.) According to Baker this gave a blue-black color which was very close to the blue-black color obtained by rust bluing. Has anyone tried this method? I've just finished making some replacement Model 99 guard screws and will try this. That is, if anyone can tell me what a suitable substitute for Marbles Nitro Solvent is. John?

Reply author: fredh
Replied on: 12/02/2003 12:07:21 PM
Message:
Stan, I think you referenced Machinery's Handbook in your Banzai article. My copy is a more recent edition, but the info is probably included in your copy. Carbon steel can be heat colored to dark blue at 570 degrees F. I use the oven for small parts, along with a separate temperature gage. Also use the oven for straw coloring, etc. This does not always make me popular around the house. One of these days you guys made read a headline along the lines of "Local engineer killed by irate wife for messing up house." Back to a serious note, I think it was Colt that used a process similar to what you described up 'til the '30's. The media (carbona? and charcoal) was used to keep the surface of the part clean (for one thing) in a sealed rotating retort (to prevent intake of air). I think you can accomplish the same goal without all the razzmatazz. But this is sensitive. You gotta watch the temp gage and part and as the color changes, take it out immediately. That's the way us backyard mechanics do it.

Reply author: JWMWITZ
Replied on: 12/02/2003 2:55:28 PM
Message:
Stan and Fred,

Stan, I tried the Swiss Armoury blue in Angier's book because the chemicals were easy to deal with, and the description said it produced a nice dark blue-black finish. It worked pretty well for small parts, but seemed to come out more dull dark gray instead of black-blue. I didn't try it on a barrel or receiver as I don't have a large enough tank to place them in. I found that Van's worked just as well and was much easier to use.

Fred, when you heat blue small parts in the oven (I have a lab oven I could use), do you pre-treat the parts in any way, such as wipe them down with acetone, or "scratch" them?

Reply author: fredh
Replied on: 12/02/2003 6:07:52 PM
Message:
John, I wipe parts with completely denatured alcohol before heat coloring. Don't know why - I just have my ways of doin things. You will be able to control temps in a lab oven, at least better than in a kitchen oven but make sure you've got a good thermometer. The resulting blue will not be as durable as a rust blue but is blue. Better correct something - I've never tried to heat blue in a kitchen oven but have strawed parts there. I have, however, annealed low carbon steels with a torch and, in so doing, have gotten a uniform blue color. Your lab oven sounds like a good bet. In case you don't have a good reference: 540 (full purple), 550 (dark purple), 560 (full blue), 570 (dark blue), 640 (light blue). Good luck with this. One of these days I want to get back to experimenting with blueing, but my plate is full now, and I'm about to get even busier. I very seldom get bored.

Reply author: Stan Zielinski
Replied on: 12/03/2003 2:40:37 PM
Message:
I went back and checked Clyde Baker's book Modern Gunsmithing. He wrote the book in 1928 (and it has been re-printed several times; I have the Samworth 1959 edition) so it should be more representative of pre-WWII bluing methods. Anyways, on page 295 there is the following:

No. 11B HEAT AND OIL BLUING …
Linseed oil (boiled or raw) 6 oz
Marble's Nitro Solvent oil 2 oz
"…Heat the parts in a gas flame to a dull red (below cherry red); hold at this heat for a minute or so, then quench in the oil mixture;lift out for a second or so before quite cool, and re-dip immediately. Keep the parts moving in the oil. …..the results on small parts are fully equal to original factory finish in appearance and wearing qualities."

I'd like to try this on some guard screws. Can anyone (John?) tell me what Marble's Nitro Solvent oil is? Is it still sold? If so where?

I have most of the standard books on gunsmithing. Dunlap's book has a long chapter on bluing methods along with formulas. John, did you ever try any of these?


Reply author: JWMWITZ
Replied on: 12/03/2003 7:01:37 PM
Message:
Stan: I checked into Marble's Nitro Solvent, and it seems to be some sort of 1920's-30's chemical mixture. My guess is that it's a dilute solution of nitric acid with maybe some iron chloride and copper sulfate thrown in. I did see that the bottles are collectibles! Anyway, I still think that if you just want to get some screws to take on a decent blue-black, then use Van's. It comes out nicely, and you can steel wool the screws a bit so they match the finish on the trigger guard or tang.

I'd like to see Dunlap's formulas. Any way you could get them posted or forwarded to me?

One thing I'm lacking is spare parts to play with. I have a few Type 38 parts that I can mess with, but no Type 99 parts. Anyone want to donate a few for experimental purposes?

John in Charlotte, NC



Reply author: Stan Zielinski
Replied on: 12/04/2003 3:32:18 PM
Message:
John, send me ([email protected]) your mailing address and I'll send you some photocopies of the formulas in Dunlap's book. Also I may still have some butchered Model 99 parts that you could practice on. Hatcher's book gives an estimate of the composition of the steel used in Japanese rifles; anyone have a more precise analysis of the steel?

Reply author: fredh
Replied on: 12/04/2003 4:37:23 PM
Message:
The steel varied part to part, as did heat treat which will affect blueing. This situation got worse and worse during the war. I just know the generalities, not the specifics. For example, early T38 bolts varied in hardness front to rear. If you were trying to blue a bolt, the results could be different over the length of the bolt with some chemicals. Years ago, I read a report where early in the war, the Japanese were bringing home all the good stuff from occupied territory such as Malasyia, (manganese, etc.) and didn't hesitate to put that in their gun steel. Early T99's must have been a sight to behold. I may have the chemical composition for receivers/barrels and will try to locate it. May be too hard because some correspondence is up in the attic. That's another area of the house to straighten out.

Reply author: JWMWITZ
Replied on: 12/04/2003 6:13:04 PM
Message:
Stan; email message sent.

Fred; What sort of timing are we talking about as far as heat bluing? I tried putting a polished steel nail in a bunsen burner today and I got a really nice blue!



Reply author: fredh
Replied on: 12/04/2003 7:50:19 PM
Message:
John, what I was trying to say earlier is that as you touch 570F you've got your color. No dwell time required. It is very hard to reach a uniform 570F with large parts, such as a receiver. You would have to heat very slowly and would take some experimentation. In the mixture Stan mentioned above, I think linseed oil is a thinning agent for the mixture to establish volume; nitric acid is a surface etching agent; the chloride and sulfate are probably the blueing agents. The last 2 items are common to a lot of blues. It would probably be pretty interesting to etch a metal surface with a 10% solution of nitric acid in denatured alcohol, dip in distilled water, then heat to 570F. Etching may present a more durable blue. Those chemicals are readily available.

Reply author: Newfoundlander
Replied on: 12/10/2003 10:40:10 PM
Message:
I just have to throw this in:

A local gunshop uses a "bluing" process called "BLACKFAST" for refinishing sporting arms. The process is a hot water phosphating chemical dip process. Bead blasted metal turns black while hand polished items take on a very deep and uniform blue similar to early 20C rust bluing.

I've been allowed to play with the tanks from time to time and I'm floored by what this stuff can do. For those interested I'll take a few pics of a Model 38 junker I put through the process earlier this year and will post them for those interested.

Their website is: http://www.blackfast.com/ie.htm if you wnat to have a peak.




 
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