Mark D's Luger Rust Blue Solution and Refinishing Tips Article

[markbritt]

Mark D’s Rust Bluing Solution and Procedures

I am offering this information in the hopes that a few experimenters, like myself, will pick up where I am leaving off and improve both the processes and the rust blue solution recipe that I am presenting in this forum post. I have spent consider time researching and perfecting my process/rust bluing solution and feel that I have done all I can do in this area. I would like to ask that if you come up with any suggestions, ideas or modifications to the solution which improve the rust bluing finish, please post them here for all to read.

Like many collectors, lugers have always had a magical allure for me. I have been fortunate over the last 20 years to pick up a number of shooter grade lugers for my collection. About two years ago, I decided to refinish a couple of these lugers to bring them back to their original look. I began by reading every luger book I could get my hands on as well as browsing the web for information on metal working and rust bluing. I decided early on that metal refinishing is an art and, rather than try to completely restore my pieces, I would focus on refinishing them with very little to no metal reworking as possible. To me, the slight pitting and scratches show the history and character of that unique luger. That path has led me down a very long road of experimentation, frustration, and finally success. During the last couple of years, I had the pleasure of completely refinishing over ten lugers as well as numerous miscellaneous luger parts and trial metal pieces.


Chapter 1 – The Solution

I read numerous posts on this very forum that discuss in detail the “Bern Browning Solution” , the “Roy Dunlap Acid Blue” solutions, as well as other old homemade solutions. I found all of these “recipes” to be frustrating in one regard – obtaining the chemicals. Many of these chemicals, once common, are considered hazardous and therefore almost unobtainable. After reviewing all of these recipes and failing to locate many of the now “hazardous” ingredients, I decided to try a different approach. There are several commercially available rust blue solutions out there that give varying results. I found that Brownell’s Classic Blue Rust solution was very easy to work. I used this solution to rust blue several lugers early on, but found that the finish lacked the dark blue look of the original lugers. It was at this point that I decided to use Brownell’s Classic Rust Blue solution as my base and would add ingredients to it in order to obtain the elusive luger blue finish.

The first thing that needed to be done was to identify all of the ingredients of Brownell’s Classic Rust solution and get the percentages (volume or weight) of these chemicals. I contacted Brownell’s and requested a Material Data Safety Sheet (MSDS) for their Classic Rust Blue solution. The MSDS sheet told me the percentages, by volume, of all ingredients:

Hydrogen Chloride 10.0%
Nitric Acid 5.0%
Hydrogen Chloride 5.0%
Water 50.0%
Ferric Nitrate 20.0%
Ferric Chloride 10.0%

Next, I converted the percentages to weight (grams) so I can use my digital reloading scale to measure out the ingredients that I wanted to add.

A four ounce bottle of Brownell’s Classic Rust Blue solution contains 108 grams of solution. I then converted the volume percentages to weight (grams):

Hydrogen Chloride 10.8 grams
Nitric Acid 5.4 grams
Hydrogen Chloride 5.4 grams
Water 54.0 grams
Ferric Nitrate 21.6 grams
Ferric Chloride 10.8 grams

Total 108.0 grams

I spent considerable time culling through old rust blue recipes to find what ingredients I could add to make the final finish much bluer. This part of the experimentation spanned a very long time with much trial and error and mixed results. Rather than bore the reader with formula’s that didn’t work, I will review how I came upon my single ingredient, Sodium Nitrate, and the results it has.

In reviewing the recipes posted in this forum, I was struck by the statement made by nukem556 on 08-05-2011 when he found that the addition of Sodium Nitrate to his solution made the finish bluer. So, I went on Ebay and purchased one pound of Sodium Nitrate (used for gold processing) for approximately $10.00. There was a hazmat fee, so the total close was close to $20.00.

After trying various amounts of Sodium Nitrate to the Brownell’s base solution, I found that the addition of approximately twenty percent of Sodium Nitrate gave the results I was looking for – a nice dark blue appearance instead of the usually grey/black finish. My exact solution, by weight, is as follows:

• Weigh 45 grams Brownell’s Classic Rust Blue Solution in a container A (this is approximately ½ volume of the bottle).
  
• Weigh 33.25 grams of hot water and put into a small container B (used to dilute the Sodium Nitrate, which resembles sugar).
  
• Weigh 11.25 grams of Sodium Nitrate and add to hot water in container B.
  
• Lastly, add container B (Sodium Nitrate/Water solution) to container A (Brownell’s Classic Blue Rust). Seal and shake the solution. You now have 89.5 grams (almost two ounces) of my solution which is enough for one luger.
  

Here is a comparision between using Brownell's Classic Rust Bluing solution straight and my modified solution:




Chapter 2 – Metal Preparation

As mentioned earlier, I wished to refinish, not restore my lugers. So, the first step is to remove the bluing and/or rust. I begin by taking the luger completely apart – I separate all coil and flat springs and place aside in a container. I do not remove the barrel from the slide. Since a luger has two large pieces (frame and barrel/slide), I usually do the frame first. When the frame is complete, I then do barrel/slide and the remaining pieces together in the same batch. I found that the luger upper (slide/barrel, toggle assembly, etc.) will all have the same finish if they are done together and in the same environmental conditions. One could argue that the frame should be done at the exact same time, however, that is a lot of work (as you will see). My results also show that there is no tonal difference between the frame and the upper being done separately. I will also note that I do the upper parts immediately after the frame is complete, so the conditions are very close to the same during the entire process.

To remove the bluing, all parts need to be free of dirt and residue. I cannot emphasize enough that once you start this process, you cannot touch the parts with your bare hands. Residual hand oils will stick to the part like glue and will completely ruin a rust blue solution application. Consider picking up at least three (3) pairs of leather gloves. Use one pair for buffing, one pair for solution application and other pair for carding.

I begin by soaking and cleaning all parts with Hoppes #9 gun cleaning solution. This cleans all powder residue as well as most dirt and oils. I then remove the parts from my Hoppes #9 bath and dry them with a paper towel. I then soak all the parts in acetone for a few minutes and then let them air dry. The acetone removes all residual oils and leaves the parts clean and ready to be stripped of bluing.

I have used two different solutions to remove the blue – the first (and quickest) is Birchwood Casey’s Blue and Rust Remover. I purchase the 3 ounce bottles in bulk (10 bottles at a time) direct from the Birchwood and they will give you a pretty good price on the larger order. The other product I use is listed on the web as “Evapo-Rust”, a water-based rust remover. I have seen this product for sale at AutoZone, but the price is twice what you can get it for on the web. I have had excellent results with both solutions, but the immersion times are completely different. If you want to “tear right into it”, use Birchwood Casey’s solution, immerse the parts for 5 minutes, remove the parts, rinse them in water. Dry the parts with a paper towel (be careful not to touch the parts), then immerse all parts in acetone for 1 minute and let air dry over night. Note: I usually do this process in the evening after work and it only takes about ½ hour. If you use Evapo-Rust, the process is the same, but I allow the parts to remain the solution overnight – it works slower, but the results are the same.

In the morning, you will notice that the parts will have a dull grey color to them. I then use a fine wire wheel for the large parts (frame, barrel/slide). You will find that the grey coating comes off very easily and you will be left with a bright shiny surface. I have not experienced any issues with stampings being removed or edges rounding as I am lightly applying the part to the wheel to remove the coating. For the small parts, I use a Dremel tool with various wire and nylon wheels and bushes to get the grey coating off. Pictured below is a trigger plate that has been stripped of bluing using the above process. Note that the stampings are clear.





Chapter 3 – Solution Application

A very important note there - Brownell’s states that their Classic Rust Blue solution should be applied within two hours of cleaning the parts otherwise oxidation will occur and cause issues with the first application of solution. I found this to be true (the hard way) and apply the solution to all cleaned parts immediately once they are cleaned.

Once your parts have the grey coating removed, you can then apply the first coat of “Mark D’s Rust Bluing Solution” (for lack of a better term). I prefer to use a wool dauber (again, available from ebay) to apply the solution directly to the part. For the frame and barrel/slide, I like the ¾” dauber and for the small parts, the ½” daubers work great. Using small tweezers or dental pliers, hold the part securely and evenly apply the solution with the dauber. Once the part is coated, I hang it on a small hanger in my basement to dry. After 1 hour, give the part a second coat of the solution (this second coat only applies to this first application of solution). Place the part back on the hanger and let it dry for six (6) hours. In researching, I found that Mauser let their solution dry for six hours between applications, so if it worked for Mauser, it will work for me. Important point - I have let parts dry for longer than six hours (like overnight) and was not happy with the results. Sometimes the finish was too dull, other times it had small spots all over the piece. The only recourse was to start over by stripping off the bluing and reapplying a first coat. After the 6 hours, the parts will have a brown/black rust appearance (see below picture).





The next step is to boil the parts in hot water for 30 minutes to prepare them for carding. I use a camp stove (or turkey fryer burner) with a large stainless steel pot I picked up at a resale shop. I place the parts in the boiling water, cover the pot and let them boil vigorously for 30 minutes. After 30 minutes, remove the parts, remember they will be HOT, and place them on a clean stack of paper towls to dry. Remove any excess water in the by dabbing the parts with a clean rag or paper towel. You will notice that the parts will have a very heavy black oxide coating on them. This coating has to be removed by “carding”.


Chapter 4 – Carding

I use “0000” steel wool for the carding process. The key point here is the steel wool must be cleaned before using in order to remove the oil that the manufacturer sprays on the steel wool to prevent it from rusting. I use a glass jar, fill it ½ way with acetone, drop in one or two steel wool pads, cover and shake. I then remove the pads and let them air dry for a few hours before use. When I do a luger frame, I use one pad for each carding session. When I do a luger upper (barrel/slide and small parts) I use two pads per carding session.

Once your boiled parts have cooled, rub them with the ‘cleaned’ steel wool. Again, it is imperative that no hand oils get on the part, so I hold them using yet another leather glove dedicated for this part of the process. As you start rubbing with the steel wool, you will notice that the dark black coating will start to be removed and you will be left with a very nice blue color. It is important to clean all areas of the part, so you may need some small Dremel bits (nylon or steel) to get into these cracks and holes. I do not recommend that you use the Dremel tool itself as the high rpm may remove the coating and you’ll be left with the shiny metal you started with. Use the Dremel bits with your hand to manually remove the black coating. Its takes a while and a bit of practice, but once you get a system down, you can remove the oxide coating pretty fast. I also found that carding off the first application of the solution is the most labor intensive. Subsequent cardings on the parts go much quicker and easier.

Now that all the parts have the black coating removed, you will find that they have a very nice blue finish. Now, it’s time to repeat solution application process by recoating the parts with “Mark D’s Rust Bluing Solution” and letting them air dry for another six hours. After the six hours, boil the parts and card again. I apply of 5 coats of solution in order to obtain the finish you see the pictures. I have applied up to 8 coats, but saw no appreciable change in the finish to warrant the extra work. As you can tell, the process is takes some time. I usually figure 5 to 6 days to do a frame and then another 5 to 6 days to do the upper luger parts. If you skip a day or two between solution applications, that is not a problem. Just make sure that the black oxide coating is completely removed from the parts between applications.

When I am satisfied with the finish, I soak all parts in water displacing oil (available from Brownell’s). This very light oil does a molecule by molecule replacement of any residual water on the part and prevents your final finish to become rusty brown. Once the part is removed from the water displacing oil, I let drain for a few hours and then spray the parts with Remington’s Rem-Oil. I usually let the parts cure for 3 to 4 days before assembling.


Chapter 5 – Straw Bluing

There is a great ‘sticky’ on the Refinishing forum about strawing parts and I use that process. All parts are cleaned, stripped, and wire wheeled as mentioned above. I place a clean cookie sheet (I have one just for this) on the top rack of the kitchen stove and turn the temperature to 450 degrees. When the stove and cookie sheet are up to temperature, I carefully place the parts on the cookie sheet. Close the stove for 6 minutes. Remove the parts and cool them down with household oil. That’s all there is to it.


Chapter 6 – Nitre Bluing

Nitre bluing is a hot blue (500-600 degrees F) process that I use to blue the grip screws and upper toggle pins. It is not required, but gives that nice transparent blue color to those parts. Nitre bluing is beyond the scope of this post as I mainly wanted to get the solution recipe and process out there.

Summary

I am sure there are a lot of comments that can be said about my process and hopefully you will add any ideas, suggestions and findings to this post. If you have any questions, please feel free to email me via a PM on the forum.

Thanks and good luck,
MarkD

[Neil Young]

Man, your shooter really turned out great--really nice job.

Neil

[mrerick]

Here's a copy of Mark's article in PDF form (posted with his permission).

Thanks again for your work and advice!

Sticky Candidate???

Marc

[lugerholsterrepair]

Mark, I read every word of your fine article with a high degree of interest! Really well done.

You have gone into great detail and your writeup is a great service to those who want to take the time and effort to approach rust bluing.

It dispelled some myths that were floating around..maybe closer to misconceptions. I had thought that the parts were hung in a moist closet to rust after the solution was applied? I appreciate your bringing clarity to a misunderstood process.

I am fascinated by this and would love to do it..unfortunately my other commitments keep me from it. I did very much enjoy your experience though..thanks..

One last thing..I don't suppose there would be any detrimental effects using some tap waters? Water is so different accross this country. Here in Yuma it has so much salt in it..it is practically undrinkable.

Thanks again for a very enjoyable read..
Jerry

[nukem556]

Mark....great job and excellent write-up! I'm gratified to see that my ideas on the sodium nitrate have come to further fruition.....after also scouring the Net ad nauseum, I found those couple of obscure references to the NaNO3 and had hopes it was the missing link....I think we agree it probably is.
You've taken to a further degree, with enhanced results, I think. I was very conservative adding the sodium nitrate to my solution....as I added it, it fizzed somewhat, like baking soda in vinegar. I concluded from this that the NaNO3 is somewhat basic, and I was leery of adding too much, thereby neutralizing the effect of the nitric acid. It appears my fears were ungrounded, next time I mix a batch, I'll follow your proportions. ( I used, by my calculations, about 1/3 of what you did).
I'm gonna be presumptious enough to add a couple points to your description of the process. The final finish you end up with on fully prepped metal that has been done with 320/400 grit polishing material is pretty much totally dependent on rust times between boiling and carding....look carefully at Mark's above photos.....the deep even orange-brown color such as on the toggle will result in a more matte final finish....the reddish-yellowish- black such as on the sideplate is a less advanced state of oxidation....if the rusting cycles are halted at his point, the final finish will be "shinier". This could be a factor if you're restoring a 1900, compared to say, an S/42.
Also, Mark didn't state for sure if he used tap water, or not....if he did, he lives in an area with nice, soft water. In my area, its full of calcium and other crud, very hard. Distilled water at Wal Mart is like .88 a gallon, and cheap insurance...don't take a chance with all your hard work!!!

[nukem556]

Oh...for those who might not have seen my older post, here is the difference even a little sodium nitrate makes.... that receiver is on the right.....and as you see on the 1900 pic, I coulda used MORE sodium nitrate...sigh, live and learn!

[markbritt]

Jerry and Bob (nukem556):

You point about the water is a valid one. I live in NW Indiana, but have well water. Being close to the Lake Michigan basin, we have very good water, but it does get a bit nasty at times. I run both a water filter and a Kinetico water softener to remove most of the iron and sulphur traces. Initially I did use distilled water, but found no difference between using that and my well water, but I think I was very lucky.

That said, I would definitely agree that going with distilled water would save you a lot of heartache!

Mark D

[lfid]

MarkD,
Awesome how to/what to article on the rust blue methods !!!
Thanks for sharing

Five key related unknowns ( for me ), anybody comments appreciated
best polish method - ie arkansas stone, wetordry sandpaper, other?
water or oil with stone or paper polish?
grit to use for high polish 1900 commercial type versus original military effect ?
how to protect bore and bare metal internal areas across the various steps ?
how to weld fix the rust pits - ie tig, mig, henrob, other ?
Bill

[markbritt]

Bill:

I will comment about the bore. After carding, I do run a brush down the bore several times to clean out any debris, carded dust, etc. I never had an issue with the rust bluing causing issues to the rifling.

MarkD

[Olle]

Excellent write-up, and thanks for sharing the results of your experiments! I have also been frustrated with all those old formulas and thinking that "surely enough there's a better way", so the information about the sodium nitrate is greatly appreciated!

[Paladinpainter]

Bravo, Mark ! Well done, well written.
So, no humidity cabinet ? The relative humidity in my basement varies with the weather. How do you think the relative humidity of where the parts dry effects the process ?
And thanks for modifying an existing product. There are chemicals in those old formulas that I dont even want around the house.

[Ice]

Excellent and very useful writeup. Thanks for posting.

Marc, thanks for posting in PDF format. That's a keeper!

Charlie

[Olle]

Originally Posted by markbritt

I am sure there are a lot of comments that can be said about my process and hopefully you will add any ideas, suggestions and findings to this post.

Again, hats off to you for not keeping your findings to yourself!

There ought to be several members who have tips to share, so I’m hoping that this thread will be the “be all and end all” on this topic. I finally got some notes together and this is not necessarily the right or the best way, just the way I have found works best for me:

Originally Posted by markbritt

I prefer to use a wool dauber (again, available from ebay) to apply the solution directly to the part. For the frame and barrel/slide, I like the ¾” dauber and for the small parts, the ½” daubers work great.

These are also available at Hobby Lobby (look in the leather works isle). I prefer to rinse them well in acetone before use, as wool often contains a greasy residue. I actually rinse everything I use (tools, rags, brushes etc) in acetone just for good measure.

Rinsing the dauber in acetone will make it much more absorbant, and it will be easier to get it damp without any excess that can drip out of it as you start swabbing your parts. I have also found that some residual acetone in the dauber will have a degreasing effect, and reduces the chances of bare spots due to accidental fingerprints etc. Another nice side effect is that the solution seems to dry a bit quicker with some acetone present.

Do not use the synthetic daubers (like the ones Brownells sells)! They are not very absorbant at all, and once you start applying the solution it will get squeezed out of the dauber and make a big mess.

Originally Posted by markbritt

Once the part is coated, I hang it on a small hanger in my basement to dry.

I heat the parts with a hair dryer right before the application. This makes the solution dry immediately, and eliminates the chances of runs, puddling and other annoying mistakes. I heat to maybe 100-110 degrees, and if the coat is still wet I’ll heat it again immediately after the application. This seems to make for a finer rust coat as well.

If you apply the solution too wet there’s also a chance that it will dissolve the previous coat of bluing (like some instructions state: “The formula contains acid, and also works as a bluing remover”), but heating the parts will help greatly. They say that you should never try and touch up the spots you miss, but it can actually be done if the solution dries quickly enough. I don’t rub it around, but a quick dab on a bare spot seems to work just fine.

If you don’t have a good place to hang the parts, put two hooks in the ceiling and hang a piece of chain between them. This and some wire hooks (made of wire hangers) will keep the parts securely right where you hang them without sliding around, and out of the reach of children, cats and other critters that may roam your shop when you least expect it.

Originally Posted by markbritt

You now have 89.5 grams (almost two ounces) of my solution which is enough for one luger.

Some instructions state that you should pour a small amount of solution into a separate container, then soak the dauber (or whatever you use for the application) and dab off the excess until the dauber is slightly damp. This will waste a lot of solution, as you can’t (or at least shouldn’t) pour any solution back into the original container.

Instead, I use cheap, disposable pipettes to move a small amount to a container, and then I use the same pipette to apply the solution to the dauber. That way I won’t use more than I absolutely need to wet the dauber, and this will make the solution last much longer. I probably use less than ½ ounce for a normal pistol project.

Originally Posted by markbritt

I begin by taking the luger completely apart – I separate all coil and flat springs and place aside in a container.

I work on any gun I can get my hands on, and as a project can take a couple of months I’ll sometimes forget where all the pins, springs and other litte do-dads go. Labeled Zip-loc bags help tremendously, and they can’t be flipped over if one of our cats happens to make its way to my work bench.

Originally Posted by markbritt

Consider picking up at least three (3) pairs of leather gloves. Use one pair for buffing, one pair for solution application and other pair for carding.

If you have a small shop like mine, it’s almost impossible to have a separate and surgically clean work area for bluing. Leather can pick up oil and grease if you happen to touch that spot you missed when you cleaned the work bench, so I use good quality vinyl examination gloves instead (Kimberly-Clark or Walgreens brand, not the cheapos from Walmart!). If I happen to touch something greasy I’ll just get another pair, and sometimes I simply to go to the sink and wash them (Yes, I’m cheap). These gloves make it much easier to work with small parts as well.

Originally Posted by markbritt

I then soak all the parts in acetone for a few minutes and then let them air dry. The acetone removes all residual oils and leaves the parts clean and ready to be stripped of bluing.

Originally Posted by markbritt

Once your parts have the grey coating removed, you can then apply the first coat of “Mark D’s Rust Bluing Solution” (for lack of a better term)

I degrease after the polish as well, and I guess you do too. Again, my shop is far from spotless and you just never know. One thing about the acetone is that it will be contaminated with a certain amount of oil and grease after while, so I use two containers and the acetone in the second one is changed frequently to keep it clean. Tupperware, Glad and similar containers actually work great, acetone won’t hurt them and I have had them sitting in my shop for months without any problems. If you get quality containers with lids that seal well you won’t have much of a problem with evaporation either.

Also, when you pick up the parts you’ll usually see a few drops hanging underneath, and the oily contamination in the acetone will sometimes concentrate right there. On occasion, there has been enough to leave a bare spot in the bluing. Granted, there won’t be much oil if you just keep the second container clean, but you’ll reduce the chances of contamination on the parts if you shake or blow the drops off.

Originally Posted by markbritt

After 1 hour, give the part a second coat of the solution (this second coat only applies to this first application of solution). Place the part back on the hanger and let it dry for six (6) hours. In researching, I found that Mauser let their solution dry for six hours between applications, so if it worked for Mauser, it will work for me. Important point - I have let parts dry for longer than six hours (like overnight) and was not happy with the results.

With all due respect, I’d caution everybody to take this with a grain of salt. The time will vary greatly with the conditions in your shop, and what works for one may not works for others. My shop is in the basement, and even if it’s heated and has a dehumidifier running to maintain some form of crude climate control, I can still see a difference through the seasons. When you start out, keep the parts under observation and go by the rust development rather than a set time frame. Once you have a fine rust coat on the parts, it’s time to boil them. I use a cheap digital hygrometer and keep track of humidity, temperature and the time it takes to develop the rust under different conditions. This makes me feel much more confident leaving the parts hanging when I go to bed.

Originally Posted by markbritt

I use “0000” steel wool for the carding process. The key point here is the steel wool must be cleaned before using in order to remove the oil that the manufacturer sprays on the steel wool to prevent it from rusting. I use a glass jar, fill it ½ way with acetone, drop in one or two steel wool pads, cover and shake. I then remove the pads and let them air dry for a few hours before use. When I do a luger frame, I use one pad for each carding session. When I do a luger upper (barrel/slide and small parts) I use two pads per carding session.

I’d like to stress the importance of not being too stingy with the steel wool. The steel wool is not very abrasive, but the dust can be. Rubbing too vigorously with dirty and wadded up steel wool can damage the bluing.

Originally Posted by markbritt

I apply of 5 coats of solution in order to obtain the finish you see the pictures. I have applied up to 8 coats, but saw no appreciable change in the finish to warrant the extra work.

The finish will depend quite a bit on the steel quality, and if you blue other guns than Lugers you’ll find that some of them take up to 15, maybe 20 coats to get a nice color, and I have done some that only took 4. It’s not uncommon to see differences in color between different parts of the gun as well. I usually keep on going until it looks good, then I give it another coat of two for good measure. The color you get after the carding is not the same as you’ll get after oiling, so you might even want to oil a few parts to make sure that you really have the color you want before you call it quits. Bringing the parts out in the sun can also reveal flaws. Take your time to inspect the final coat. You want to find out before you quit, not after the gun is assembled.

I’m far from an expert, so feel free to comment on any of the above. Again, these are the methods that work best for me and not necessarily what works for others, so my best advice is to get some discarded gun parts and experiment a bit before you “go hot”. I had to go through a lot of trial and error before I finally was able to produce a nice rust bluing, but the frustration of this is just part of the process.

[Paladinpainter]

Mark, et al:
I've had a chance to blue 4 guns since Mark shared the secret of Sodium Nitrate: a modern S&W, a Bolo Mauser, a Remington 700 ( control), and a Winchester 1895.
For a solution, I used 2oz of Brownell's Rust Bluing with 40grams of sodium nitrate, applied with mops of paper towel, rusted in a humidity cabinet, boiled in distilled water, and carded on a .0004 inch stainless steel wheel
Here's what I found:
The Model 19 does indeed have some blue spectral high lights. For comparison, on the left is 1920s commercial, the S&W is in the middle, and a Pilkington's blued 1916 Erfurt. The pictures dont convey the colors very well, but the highlights of the S&W is closer to the commercial than the Erfurt.
The Bolo Mauser seemed to rust quickly in my humidity box, however the finish was kind of thin. After many trips to the cabinet, I had very rich blue/black finish with blue highlights.
At the same time I did the 'smith, I blued the Remington 700 with unadulterated Brownell's Rust Bluing as a control. It came out a deep satin black as I expected.
It was with the Winchester 1895 that the sodium nitrate really did its magic. There is no missing that the metal is a deep lusterous blue. As soon as I have a chance, I will post a photo comparison with a standard rust black finish.

John

[Paladinpainter]

Mark, et al:
Here are the pictures I promised. Of course, it doesnt show much, I probably should have gone outside. The sodium nitrate barrel is the one on the right/bottom. When you hold them, side by side, the silver/blue highllights are evident.

I stumbled across this photo of my sodium nitrate Bolo Mauser next to a full sized C96 blued with a standard rust blue. To my tired eyes, the Bolo is a lot bluer.

These results convince me that Mark has hit on a formula that works. Thanks you, Mark. From the color of the Model 19, the type of steel seems to make a difference in the nature of the blue. It suggests that each type of steel will blue best with a specific formulation.

So, what's going on here ? Without any education that would qualify me to venture an opinion, I agree that the addition of sodium nitrate creates a molecular structure that reflects light the blue part of the spectrum. I dont know why and I'm not sure I need to. I'm going to concentrate on getting consistent, predictable results.

Does any one have any Show and Tell to share ?

[cirelaw]

Wow you make open heart surgery seem a breeze!

[Paladinpainter]

I'm lucky to have time to put into these projects. Mark is the real Doctor of Bluing here.

[markbritt]

Palidinpainter:

Excellent job on the pistols!!! I am glad that you guys are taking this to the next level. Again, any ideas to better the process should be posted!!!

Great work
Mark

[Olle]

Originally Posted by Paladinpainter

So, what's going on here ? Without any education that would qualify me to venture an opinion, I agree that the addition of sodium nitrate creates a molecular structure that reflects light the blue part of the spectrum.

It's funky for sure, and sometimes you get the blue color with any bluing just because the quality of the steel. It's darn near impossible to capture the difference in a picture as well.

By the way: Where did you find the sodium nitrate? Was it in your "treasure trove" of chemicals, or do you have a good source where you can buy small amounts?

[chromeed]

You could buy it at a Farmers CoOp in 50#bags for about $15.00 before the Oklahoma City Federal Building bombing. I bought a bag about 20 yr. ago.
Sodium Nitrate is also one of the components of Alkaline Hot Bluing which I have a formula for.
If anyone is interested I can dig it out but I must caution that it is a molten salt bath very Hot.