Home hot blue picks.

[fido]

I don't usually post much but I got to share.

I finally got at some iron that needed it. I wish I had before picks. I am very happy with the blaaaack.

It's hard to photo the new finish, I would have to say the blue looks 99% of of a new gun.
Thaks to the ones that helped.

Its amazing what lye and salt peter will do at 292F.

http://img.photobucket.com/albums/v510/sdeering/P5160222.jpg

http://img.photobucket.com/albums/v510/sdeering/P5160224.jpg

A couple of old Parker's 30-06,243 an old savage that my dads grandpa handed down. I had to make a new handle for the bolt.
No jokes about the wives flowers in my garage avoiding frost at night.
Enjoy.
STephen

[DLCTEX]

Please elaborate on formula used. How much lye and nitrate? One trip in the tank?
Dale

[scrapcan]

how about a picture of your hot blue setup. Tanks, burner, etc..

[fido]

1 lye to 1/2 potassium nitrate and dystilled water. You add salts till you bring up the boiling temp to 295f then add water to keep it there ( water evaporates as you are bluing), this is the worst part . Spitts lots of hot lye at you. Adding water to 295f water kinda like adding water to molten lead. Don't get it over 300f or your salts will die.
One soak in the salt for 20min.
I will take a pick of my tank not pritty but it works.

[BeeMan]

The formula sounds like what Linstrum posted some time ago. I recall he said to replenish boiled off water by adding ice. It melts and adds the water slowly. Can't recall if I needed to do this, as I only blued a few small parts a couple years ago. Yes, it gives nice results.

BeeMan

[fido]

I may have to try that in the future. Thanks

[DLCTEX]

Thanks, I need to reblue my 1911. I had thought I would use one of the paints or phosphates, but just couldn't get used to the idea. This is more like my taste. Dale.

[imashooter2]

Interesting thread on AR15.com about a guy that blued his pistol in an old crock pot:

http://www.ar15.com/forums/topic.html?b=1&f=5&t=528694

[fido]

Kool link.
Thanks

[Molly]

> ...You add salts till you bring up the boiling temp to 295f then add water to keep it there ( water evaporates as you are bluing), this is the worst part . Spitts lots of hot lye at you. Adding water to 295f water kinda like adding water to molten lead.

Old gunners cure for this is to make a bowl of steel wire mesh - old fashioned window screen stuff. Turn it upside down and push a small dimple in the dome. Now use coat hanger wire to suspend it at one end of your salts tank, with the edge of the screen in the solution. Add water through the dimple. The water will still cause it to spatter like BLEEP, but it'll all be inside the mesh, with none aimed at you. Another approach is to use a short section of 4 to 6" pipe the same way, and put a steel mesh (take a magnet to the store) kitchen screener / sieve over the top before adding the water.

> Don't get it over 300f or your salts will die.

Well, I ran my tanks from 305f to 310f, but then agin, I was using a somewhat different formula.

HTH

[Molly]

Fellows, I used to help out some beginning 'smiths, and wrote up my blueing procedure for their reference. I thought I'd post it for the information of anyone interested. No guarantee that it's the best possible, but it's simple, easy, and worked well on a large variety of steels.

"Gun Bluing"
(Caustic Black Iron Oxide)

Bath Formula

Chemical Ingredient Weight Weight One
Symbol Materials Measure Ratio Gallon
H20 Water (softened) 4 Pounds 64 5.2 Pounds
NaOH Sodium Hydroxide 4 Pounds 64 5.2 Pounds
NaNO3 Sodium Nitrate 1 Pound 16 1.3 Pounds
NaNO2 Sodium Nitrite 1 Ounce 1 1.3 Ounces

Some Primary Hazards
(A partial listing)

Dry NaNO2 and NaNO3 are potential high explosives that can be ignited by heat or shock. NaOH will rapidly attack and dissolve skin, flesh, clothing, aluminum, zinc and tin. Spills should be flushed quickly with vinegar or lemonade to neutralize the caustic and minimize damage. Mixing dry NaOH and water generates a LOT of heat, and can cause the tanks to boil over suddenly. Use already prepared commercial 50% caustic solutions available from many chemical companies or supply houses, or be sure that the caustic is added and dissolved in small quantities, and is allowed to cool between caustic adds.

Bath Operation

If a used bath won’t work, try adding a little more caustic or nitrate before you re-make the solution from scratch. Wear caustic resistant gloves, aprons and eye protection at all times.
The solution tanks must be stainless steel, steel or plain iron (not galvanized), with welded seams. Soldered or brazed seams will dissolve in the bath and ruin the solution, tanks, and whatever gets leaked on.
Add water if it is necessary to cool the bath or lower the boiling temperature. Just turning the heat down will not let it work properly, as it must be boiling gently. Adjust the bath to boil at 275 F (135 C) to 302 F (150 C) by adding water slowly through a large fine steel mesh to catch spattering caustic. Don’t go over 310 F (155 C), or the solution will be damaged.
Preparation: Polish metal as required. Bluing will not cover poor polishing. It will only make poorly polished white steel into poorly polished black steel. Degrease the metal, preferably by boiling in a detergent or caustic degreasing solution. Then put them in the hot bath right away. Otherwise, protect polished parts from rust with light oil until ready to degrease and blue them.
Do not put non-ferrous parts in the bath, as they will dissolve, ruining the part and probably the bath as well. Anything a magnet won't pull on (like wood, glass, aluminum, plastic or stainless steel) won’t blue.
Do not plug the bores: The high temperature will cause the pressure in the barrel to increase, and may pop the plugs out and splatter caustic. Instead of plugs, handle parts with steel wire hooks or tongs. Hang them out of contact with the sides or bottom of the tank, but small parts can be placed in a steel wire basket. Let them boil for ~ 10 minutes, then remove and rinse in clean, cold running water. Check color after scrubbing with clean, degreased “0000" steel wool. Return to the tank as necessary until the color is satisfactory. Rinse thoroughly in clean, cold running water. Dry parts, oil and reassemble gun.

Trouble Shooting

Color problems: No bluing color or a powdery black that scrubs off can be caused by a bath that’s worn out or damaged from overheating, wrong amounts of chemicals or (in old baths) by caustic being used up by CO2 in the air. Poor blackening or red or purple tints can be caused by combinations of too low temperature, copper contamination, insufficient NaNO3, very high carbon steel, cast iron or insufficient time in the bath. Slight traces of copper or copper salts will poison the solution and give a red tint to the color, or will stop the bath from working altogether. Splotchy spots with no color or mottled colors are from poor cleaning or oil contamination in the bath. Sometimes this can be fixed while bluing by scrubbing with degreased “0000" steel wool. Green or pale blue colors can be caused by low temperature or not enough boiling action in the bath.

[fido]

Good info Molly Thsnks.
Brownells info says not to use stainless tanks. I think it has something to do with the chromium disolving in the bath.
Stephen

[fido]

or maybe chromate?

[Molly]

Good info Molly Thsnks.
Brownells info says not to use stainless tanks. I think it has something to do with the chromium disolving in the bath.
Stephen

Could be, I dunno. But I never had any problems, and it was sure nice not to have to deal with a rusting rinse tank all the time.

Hmmm. You know, there are TWO types of stainless steel: One based on chrome, and one based on nickel. Maybe mine were the nickle type. I dunno.

[fido]

It might have something to do with disposal. Baaaaad for the environment are chromates.
Stephen

[scrapcan]

Fido,

It is interestign that you talk about chromates. While working in an environmental lab that was on it's own sewer system we had to collect the potassium dichromate that we used for organic carbon analysis. Yet our sister lab in another town could just dump it into the drain. Never could understand their willingness to follow the dilution is the solution attitude. To me the contaminant is still there, just below som set limit or arbitrary value. Same thing goes for film developers.

Anyway I did not mean to hijack the thread.

[fido]

The reason I am familiar with it is in the past chemical plants used to use it in the cooling towers. I think it was to control the growth of algae and other critters. Or maybe it was corrosion. Can't remember. Anyway it is baaaad for the environment and humans. I think there was a movie made about it.
Erin Brockivich or something like that. I just looked it up it was chromium.
probly not much difference health wise.
Be cool play safe kids
Stephen

[DLCTEX]

Is caustic Soda the same as lye? I can get a lot of it from the oil field work here. There was a bag lying on the shoulder of the road a while back. Dale

[Molly]

Is caustic Soda the same as lye? I can get a lot of it from the oil field work here. There was a bag lying on the shoulder of the road a while back. Dale

Yes, Caustic Soda IS the same as Lye, just a different name, that's all. But be careful, and do some serious thinking before you pick that bag up! No offense intended, but the fact that you needed to ask suggests that you are not familiar with the stuff. It's nothing for the uninformed to play with! See my post on blueing formula in this thread.

Caustic is DANGEROUS stuff, and no mistake. Not only will it dissolve most anything organic (like shoes, clothes, skin, hair and eyeballs) in a bloody hurry, but it gives off heat when it's dissloved in water. In fact, it gives off so much heat that - unless done right - it can result is a sort of volcanic type eruption from the sudden generation of a lot of steam, and throw boiling hot caustic solution all over the area. Believe me, one time will provide all the entertainment of that sort you will ever need. Not to mention plenty of unattractive scar tissue when the injury finally manages to heal. Caustic burns do not heal rapidly. And simply touching the stuff is enough to get burnt very badly. It can - and probably will - take a lot of the skin off of your hands very nearly as fast as you can take a pair of work gloves off your hands. And it will feel like you had your hand stuck in boiling water.

If you have a legitimate use for the stuff, let me suggest you visit the nearest neighborhood chemical plant and buy some that is already dissolved. It's commercially available in several concentrations, but 50/50 is probably the most common. I also strongly suggest that you look up the MSDS of caustic on the internet, and learn something about the stuff before you use it for anything at all.

[DLCTEX]

I am somewhat familiar with caustic soda, we used it in a vat to clean engine blocks when we were in the auto/tractor repair business. I was never in on mixing the solution, as we had and old fellow who insisted on every one clearing the area while he mixed it. After he left, we got a steam cleaner. I was also around it when I did a stint roughnecking, a derrick hand used it one time to melt ice off the boards he stood on. It didn't take long to learn not to look up, as that really burned your eye. He mixed some in water and used it to clean the grime off his aluminum hard hat, really made it shine. A worm(new hand) saw it and wanted to know how he did it, so was instructed to remove the liner and soak it for a while in the bucket. Of course it melted. You could lay a Coors beer can on a broken bag and the next day nothing was left but the clear coat and logo in the shape of the can. I just was never aware that it was the same as lye, but when caustic was mentioned in the above tread I made the connection. I was also around when lye was used in soap making when I was a kid. Dale

[felix]

Always, always, always have 5 percent vinegar nearby ready to wash your hands after getting anywhere close to any kind of sodium or potassium hydroxide. It is best to deal only with the kind already mixed up like Molly says, or in prill form (beads). Never even contemplate buying it in powder form because it can blow around too easily. Yes, it is that dangerous. ... felix

[jbunny]

Molly; can i substitute potasium nitrate instead of sodium nitrate in the bluing formula
TIA
JB

[robroy]

I have a black t-shirt with a bunch of white sploches from the "volcanic eruption" of a bluing tank. I was adding water to cool it down and got a bit too much a bit too quick. None in the eyes (safety glasses rock. A face shield would have been better) some on the corner of my mouth. I rinsed as best I could and got a shower just a few minutes after the rinse. My lips burned for a few days and things didn't taste right for a bit but everything healed. All in all I'm one lucky S.O.B.

Moral of the story: Know the materials with which you work, read the MSDS, Use the proper personal protedctive equipment.

Sermon over

[Molly]

Molly; can i substitute potasium nitrate instead of sodium nitrate in the bluing formula
TIA JB

Hi JB,

In theory, you have to adjust the weight to compensate for the differences between sodium and potassium. But they really aren't all that different, and for all practical purposes, I think you could interchange them OK. It might make a slight difference in how fast the solution works, but I wouldn't expect any major changes. Good luck.

[felix]

That's right, Molly, if the blue-ing is anything like the photography use of the chemicals. Can expect a color shift towards "brown" with potassium, but that would depend on the metal being blued anyway. Might never happen. On the other hand, use half again more potassium as the sodium hydroxide for the same "speed" of blueing. The potassium might be more sensitive to max temp as well, so use a little colder bath until proven otherwise. How much colder? Don't know. Gotta' play with it. ... felix

Sodium/potassium sulfate will extend the temp limit in terms of too hot of a bath, at least in photography. So, it never hurts to have some of that around. It has no color shift effect, but will slow down the reaction. Potassium sulfate is typically added to clip the peak temps in gun powders. ... felix

[jbunny]

thanks guys,gals; in this web page, he talks about useing ammonia nitrate.
have u any experiance with this. i have never done this and i want to be well armed
before i try this
TIA
jb

http://www.blindhogg.com/homemadesalts.html

[Molly]

thanks guys,gals; in this web page, he talks about useing ammonia nitrate.
have u any experiance with this. i have never done this and i want to be well armed
before i try this
TIA
jb

http://www.blindhogg.com/homemadesalts.html

Forget this guy! I don't know how many guns he may have blued, but he sure didn't blue many with ammonium nitrate! Nobody does. The first time you fill your home with strong ammonia fumes is enough. Was for me anyhow.

If you want to know what it will smell like, take a quick sniff of your honey's bottle of household ammonia. Smell it sitting down, so you won't hurt yourself too badly by falling over in shock. Then after you regain the ability to breath again, your eyes have quit overflowing with tears and your sinuses have stopped screaming at you, you can go back to his web site and look for the large cattle block of salt that he should have posted for consumption along with his bluing advice.

On reflection, maybe I'm being a bit harsh. After all, it WILL blue guns quite well. But then, so will turning an acetylene torch on them. I suppose that if you can arrange your schedule so you can do your bluing outside your home, and during a major windstorm, it might work out OK.

Same goes for substituting ammonium hydroxide for sodium hydroxide, or ammonum anything for something else. The problem is that when salts dissolve in water, they ionize into separate materials, each with its own properties. The pertinent property of ammonia is that it is QUITE volatile, being a gas at ordinary ambient temperatures. Ask any farmer who uses anhydrous ammonia to fertilize his fields. Try putting it into a 300 degree environment, and it not only becomes a corrosive gas, it becomes a corrosive gas with great vim, vigor and enthusiasm. It's just barely handleable (without special equipment) as a VERY dilute solution in water, as your wife uses it.

OK, gotta backpedal just a little, and edit above. After writting it, I checked out the site, and found the following:

"ammonium nitrate fertilizer has several negatives: First, it gets attention from the FBI and you can end up "a person of interest". Second, when adding it to the lye, copious amounts of concentrated ammonia gas are produced and ammonia is very dangerous to living things! "

So he DOES provide a warning, but that is all he says. He leaves the impression that (dispite his warning) this is an acceptable or standard practice. I strongly disagree. You decide for yourself, because you will live (or possibly die) with the results. Just consider that he is telling you that you will generate '... copious amounts of concentrated ammonia (gas which is) dangerous to living things! '

[AviatorTroy]

To add to the previous post about horrible fumes and 300 degree lye splashing on my arms, I wonder if you guys have any real objections to some safer and far easier alternatives...

I just redid a Mauser action with a 2 groove springfield barrel and I used this stuff.

http://www.midwayusa.com/viewProduct/?productNumber=897836

I though it turned out pretty well. The barrel did not turn out EXACTLY the same as the reciever, well the steel was only 40 years newer and manufactured on the opposite hemisphere as the receiver and other metal parts on the gun.

Is this stuff going to wipe off like India ink? Seems like so far, so good and every time I clean and oil the gun the finish looks deeper and better.

[Molly]

To add to the previous post about horrible fumes and 300 degree lye splashing on my arms, I wonder if you guys have any real objections to some safer and far easier alternatives...

I just redid a Mauser action with a 2 groove springfield barrel and I used this stuff.

http://www.midwayusa.com/viewProduct/?productNumber=897836

I though it turned out pretty well. The barrel did not turn out EXACTLY the same as the reciever, well the steel was only 40 years newer and manufactured on the opposite hemisphere as the receiver and other metal parts on the gun.

Is this stuff going to wipe off like India ink? Seems like so far, so good and every time I clean and oil the gun the finish looks deeper and better.

Thanks AviatorTroy,

I should have mentioned the cold blue alternative. While MOST cold blues contribute little beyond some color that wears off quickly, there ARE some exceptions that really do a decent job. Brownell's sells OxyphoBlue, which is one of my favorites. They also sell other blueing products that will leave a lasting finish, though they are intended for double shotguns, and take a fair bit of elbow grease. I'm not familiar with the product you cite, but for the guy who only wants to finish one or two guns, they are really worthwhile. It takes a while to recoup the cost of a hot blue setup, and some of the cold blues do a decent job.

HINT: Read the directions that come with your cold blue. If they tell you to polish with steel wool, it's a clue that the finish is probably going to be reasonably durable. If they don't ... well, that's a clue too.

[jbunny]

boy; i'ma gona make sure that i don,t ask questions about reloading
and shooting guns. that could open up a real big can of worms.:smile:
jb

[Centaur 1]

I work in aerospace and we used to have a vat of sodium hydroxide that was heated and it had a gn2 bubble agitator to speed the degreasing operation prior to passivation. I was given a set of flight caps, which were used to cap off ports in the fuel and oxidizer tanks on the Titan 4 rocket. I glanced at them and assumed that they were made out of stainless, then I lowered a basket containing the caps into the lye. When I went back 45 minutes later to check on them they were black and pitted. Lye and aluminum don't mix.

[Centaur 1]

Has anyone done any bluing using melted stump remover(potassium nitrate)? I've read that you can melt the granules and dip the parts to be blued in it until it reaches the desired color then quench the metal in a vat of oil.

[Molly]

Has anyone done any bluing using melted stump remover(potassium nitrate)? I've read that you can melt the granules and dip the parts to be blued in it until it reaches the desired color then quench the metal in a vat of oil.

Ummmm, please reference above posts: Potassium nitrate (and all other nitrates) belongs to the class of high explosives. I suspect this would blue steel all right, but the only way I'd even consider using this technique is by proxy. Long distance proxy. I suspect the very notion would give your life insurance agent the vapors.

[Dave Berryhill]

I think he is referring to nitre or fire bluing, which is the process that gives the cobalt blue sometimes found on pins, screws and other small parts. I'm not sure of the chemicals used though. Here are the instructions from Brownells:
http://www.brownells.com/userdocs/learn/Inst-362%20Nitre%20Bluing%20Bluing.pdf

[scrapcan]

Another option for cold blue is the Rust blue process. You can use alot of stuff to create the oxidizing step. It takes a bit more time than a hot blue, but it can be beatiful and is a very durable finish. You do still need to boil the parts in water to stop the reaction and then follow with a good preservative.

It is a good process and in many parts of the country you don't even need the sweat box for humidity.

[Molly]

I think he is referring to nitre or fire bluing, which is the process that gives the cobalt blue sometimes found on pins, screws and other small parts. I'm not sure of the chemicals used though. Here are the instructions from Brownells:
http://www.brownells.com/userdocs/learn/Inst-362%20Nitre%20Bluing%20Bluing.pdf

You've made a good point, Dave, and thanks for the reference. I've never used the process, and a quick read of Brownell's instructions suggests that was a good decision. Brownell's process makes regular hot blue look like childs play. I didn't realize the full ramifications of the process, but it just makes me more adamant in advising against it. I knew it would give a pretty blue, BUT: I stand by my caution that nitrates are high explosives. I would STRONGLY recommend against heating / melting any high explosive. Brownell's states that their formula is especially made for stability and low melting point. I dunno. I suppose they could have some sort of eutectic blend to desensitize the mix like sawdust or clay or fuller's earth will desensitize nitroglycerine. Maybe I'm being overly cautious; I'm no expert on explosives. But I recognize that limitation, and want to keep my house on its foundations, with my family intact. I won't use the process myself. Anyone who wants to, does so against my advice.

One note though: Brownells states that it is possible to aproximate the bright blue on guns from the 1950's and earlier with their formula. As a matter of general interest, I understand that the nitrate process used by S&W consisted of hanging pistols in large racks that were placed in rotating drums, and hot nitrate beads (NOT molten compound) were poured over them until the steel took on the desired finish.

Personally, if I found ordinary blueing unacceptable for whatever reason, I believe I would be strongly tempted to try one of the spray-on-and-bake finishes that have come out in the last few years. I once had a banged up and badly pitted Stevens 310 double (with good bores) that wasn't worth the labor to polish, but I wanted to give the metal some protection so it wouldn't corrode too badly in my trunk. I went up to Home Depot and got an aerosol can of semi-gloss black, and sprayed the barrels with it. The pitting disappeared except to a pretty close inspection, but I still had some questions about the durability of the coating. I mused over the situation for a while, and went back to pick up an aerosol can of semi-gloss polyurethane clear. As a former paint chemist, I have a real appreciation of how tough they can be, so I gave the barrels a couple of coats of polyurethane over the black. They looked so good I had to clean up the rest of the gun (action and stock) to match. Interestingly enough, I really didn't care for the finish at first, because it had a surface drag: It didn't feel hard and slick like steel should. But after it sat around for a week or ten days, I picked it up to go shoot it, and darn if it hadn't hardened up, and it felt slick as if it were buttered. All told, you had to be pretty close to tell it from a new gun, which is a pretty good outcome for the rusty, pitted junker it started as. My stepson liberated it, and it's still going strong as far as I know. At any rate, he hasn't asked me to refinish it yet.

[Molly]

Another option for cold blue is the Rust blue process. You can use alot of stuff to create the oxidizing step. It takes a bit more time than a hot blue, but it can be beatiful and is a very durable finish. You do still need to boil the parts in water to stop the reaction and then follow with a good preservative.

It is a good process and in many parts of the country you don't even need the sweat box for humidity.

Yeah, I referenced it in message 29 above. It IS a good process that will give a good, durable blue without tanks or lye, etc., and generally gives a uniform color on different steels. But it's slower than mollases in january, and will sure help you build up your biceps. I prefer to use OxphoBlue myself: Fast, good color, and wear resistant enough that you finish it with a good scrubbing with steel wool.

[jbunny]

Has anyone done any bluing using melted stump remover(potassium nitrate)? I've read that you can melt the granules and dip the parts to be blued in it until it reaches the desired color then quench the metal in a vat of oil.

IIRC, the melting temp of theses salts are in the 750 Deg f or so and u are in the serious annealing temps. do a google search on annealing temps.
jb

[scrapcan]

Molly,
You did mention it somewhat but did not call out the process. chemical cold blue and slow rust blue are different and I thought it should be called out.

The process can be slow, but you can speed it up also. You can build a simple humidity chamber and put a light bulb to create heat and moisture. The camber can be a lot of things. A friend of mine used a heavy clear trash bag and as a tent with the barreled action stood on a small dowel that had a base ov 2x12 wood. He then used a small night light plugged into a cord to created just a little heat. It would bring the fuzz up really well. He had to use degreased steel wool to know the rust down and begin the process again. he did this until the color he liked was achieved. He then used a piece of 4 inch pvc pipe with a cap and poured boiling water from a turkey fryer pot into the tube with enough room to submerge the barreled action to stop the process. then followed with oil.

The process does not take a lot of dangerous things and the littel bit of elbow grease used with steel wool is not alot. You can dispense with the elbow grease if you want to buy a degreased fine wire wheel.

The process of browning a balck powder kit gun is the same only it may use a slightly different solution or it may not go through the hot water stage (which causes the deep blue color).

[Molly]

> You did mention it somewhat but did not call out the process. chemical cold blue and slow rust blue are different and I thought it should be called out.

You're right. I was just thinking of alternatives to hot blue.

> The process can be slow, but you can speed it up also. You can build a simple humidity chamber and put a light bulb to create heat and moisture.

I never built a humidity chamber, which is probably why it took a lot of coats and elbow grease when I used it. I only used it a couple of times, and went to something that was easier for me to work with.

[Molly]

---Quote (Originally by Molly)---
...I stand by my caution that nitrates are high explosives...
---End Quote---
They are not. They are oxidizers.

Not sure who posted this note, but I can't find it anywhere except on my e-mail notes. Be that as it may, it's true that nitrates can be (and are) oxidizers, but they are ALSO explosives.
ALL nitrates are explosives to a greater or lesser degree. Haven't you ever heard of using nitrate fertilizers to boow out stumps instead of more expensive dynamite? Well, the same nitrate fertilizer that will remove stumps will also do a fine job in a blueing tank. I know. I've used it for years, buying it from a local farm supply store.

[S.R.Custom]

That was me. Part of a much longer post on nitre bluing, it disappeared when I tried to edit it for clarity. I was too tired to reconstruct the post, and went to bed instead. Apparently you got the email notification of the original post before it disappeared.

Anyway, KNO3 is an oxidizer only. It is only in conjunction with a combustible agent that explosives are made. In and of itself, it is not combustible, much less explosive.

The properties are in the table on the right; note under "Hazards" where it says "non-flammable":
http://en.wikipedia.org/wiki/Potassium_nitrate

[Molly]

Anyway, KNO3 is an oxidizer only. It is only in conjunction with a combustible agent that explosives are made. In and of itself, it is not combustible, much less explosive.

The properties are in the table on the right; note under "Hazards" where it says "non-flammable":
http://en.wikipedia.org/wiki/Potassium_nitrate

Hi Supermag. How about we share credit on this one? From your reference: "... sodium nitrate, (is) a similar nitrogen compound that is also used in explosives and fertilizers. "

All nitrogen compounds will yield nitrogen on decomposition by heating. The nitrogen is the actual explosive material. But notice the context of our discussion: We were discussing HEATING the potassium nitrate. Now I admitted being no explosives expert earlier.

But I do think I have some commmon sense. I don't juggle dynamite, nor do I deactivate dud bombs for a hobby. Nor do I knowingly heat materials that will develop explosive nitrogen gas at unknown rates and in unknown volumes. Nitroglycerine will ALSO develop explosive nitrogen gas upon decomposition from heating, even though it is also normally stable at room temperature. To me, that property is the qualifying characteristic: I consider both compounds explosive. The difference lies only in their different readiness to release their nitrogen.

[jbunny]

i hot blued my martini today. not perfect but for the first one, i'm happy.
it was to windy out. but i wanted to do it outside. my solution was i suspect,
a little to weak at first as i could not get the temp over 250 deg F for quite a while.
as the water boiled away and solution got sreonger, up came the temp.
jb

darth vader is alive and well
http://i138.photobucket.com/albums/q273/MOUICH/darthvader.jpg




heres the parts
http://i138.photobucket.com/albums/q273/MOUICH/hotbluemartini.jpg

[S.R.Custom]

Looks fine for a first time. Good color. A lot of guys the first time out --yours truly included-- get the temp too hot, and the parts come out reddish...

You have to watch those SS stock pots. All the ones I've seen have rivets holding the handles on... and the rivets are made of aluminum, which is eaten by the Sodium Hydroxide and contaminates the solution...

[jbunny]

ur 100% correct on the aluminum rivets. i drilled them out and made stainless
one from 1/4 in bolts before i started blueing.
regards
jb

[S.R.Custom]

I figured you probably caught that. I just mentioned it in case anyone is playing along at home.

[Lee]

Nitrogen is not an explosive material.
Nitroglycerin will not develop explosive nitrogen gas upon heating. Because nitrogen gas is not explosive.

There are many explosives which do not have, use or require nitrogen.(Think perchlorates)

The rapid expansion of super heated, high pressured(especially when confined) gases is what constitutes what we commonly call an explosion. That is what happens in the cylinders of your auto. That is what happens when you light a firecracker. That is what happens in the barrel of a .22. And that is what makes the "Whooommppp" when you burn the trash, and like I do, add a quart of gasoline/stand back ten feet and throw matches at the pile.

The natural gas pilot on your furnace burns 24/7 all year long, quietly. But fill a garbage bag with it and some air(oxygen if you feel the need to exclude the nitrogen from the air) and then light it off. Not so quiet.

Research the combustion products of black powder. Those reactions are still not completely understood. But it is the sudden generation of hot, high pressure gases that causes the explosion. And all that the nitrogen does is provide the carrier for the oxygen that does all the work of combusting the charcoal and sulfur.

Ammonium nitrate. The oxygen gets things going. The elevated temperatures causes the ammonia (NH3) to split into nitrogen and hydrogen. The hydrogen then burns/explodes with oxygen, while the nitrogen just sits there, going along for the ride. Again, generating high temperatures and pressures, and great volumes of gas, you have an explosion.

SuperMag hit the nail on the head;

"Anyway, KNO3 is an oxidizer only. It is only in conjunction with a combustible agent that explosives are made. In and of itself, it is not combustible, much less explosive."

[Molly]

I don't quite know how the discussion turned to nitrogen gas. I intended my remarks to pertain to nitrogenous compounds in general. IE, NITROglycerine, triNITROtoluene and the like. They vary considerably in their properties, but to the best of my knowledge, ALL NITROgenous compounds have explosive potential.

As dust and gas, almost anything will burn and has explosive potential. This includes rock dust and baking flour. Witness coal mine disasters and grain silo explosions.

[Just1Mor]

Not to beat a dead horse, but i have been doing much research on the bluing process and the chemicals that are entailed to get the job done. I think the answer to the question is in the title of the COMPOUND you are talking about.

you need 3 things for fire:

Air (o2)
combustable material (anything carbon/organic)
and spark ( the start of the sequence of events where rapid expantion of hot gas takes flame)

Gasoline by itself will not burn, you must have the right air to fuel ratio before it will react. drop a match in a bucket of gasoline (not Desiel) on a cool day, nothing happenes because there is not enough oxygen to set off the reaction.

for example nitrogen is added to things so you can fit more O2 into a volume of space therefor higher explosions. In cars the more gas/less O2 you add to the mixture the cooler the car will run, take gas away and the burning temp raises because of a complete burn thoughout the space. In Nitromethane, methane is the carbon bases combustable and Nitrogen is an agent that provide a higher amount of O2 to be able to fill that space. In nitrous oxyde the nitrogen freezes the air going into the intake there for more O2 can follow, more air, bigger boom, faster you motor will go caput because they arent meant to run that hot. flour in particles mixed to the exact ratio of O2/Flour (Carbon Base) will explode but needs to be set off i.e., static discharge.

[Just1Mor]

Sorry my question is about the ether that was used in the oldtimer's solutions. I am guessing that it draws any oils remaining in the metals out to provide a more complete blue. Also about what chemicals can you add to produce different color effects without depleating the solution.

[David2011]

Back to the bluing part of the conversation. . .

Spattering when adding water to hot bluing salts is easily avoided by pouring the water onto a thin board 2-1/2" to 3" wide at a fairly flat angle. The one I use is about 1/2" x 3" x 24". The bottom end of the wood should extend into the salts. That provides a more gentle entry of the cold water into the hot salts. You still have to pour gently but the cold water stays on top of the hot salts because it is less dense than the salts. It heats unevently as it's stirred in after being poured onto the surface of the salts. Almost all spattering is eliminated with a little care.

David

[Molly]

Another way to avoid spatter when adding water is to take a length of 2 or 3 inch pipe and tack on a hook so you can put it into the tank with the bottom of the pipe setting well below the surface of the liquid. Then cap it with a bit of iron or stainless fine wire mesh from the window screen department of your local hardware store. DO NOT USE ALUMINUM OR PLASTIC MESH SCREEN.

To use, just pour the water through the mesh into the solution. Yeah, it'll spatter like mad, but the screen will catch every bit of the spatter, and none will get to your delicate skin or eyes. Easy and cheap to set up, lasts just shy of forever.

[Just1Mor]

Does anyone know what the Spirits of Ether was used for in the solutions back in the day? Cant seem to find the stuff.

[marten]

Hi, long time lurker here!
Any of you guys know the formula for blacking stainless?

[David2011]

I believe Brownell's makes a hot bluing salts type product for blacking stainless. I would give more info but can't get to their website at the moment, probably due to a problem with my Internet service.

David

[thehouseproduct]

http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi?;act=ST;f=22;t=24170
http://castboolits.gunloads.com/showthread.php?t=113049