acidic or alkaline??

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I have always assumed that BP fouling is somewhat acidic, but have also read over on the SASS Wire that it is actually alkaline. So for the chemists out there, what is the answer??

Somehow, I've got a feelin' I'm gonna get two answers, probably in about equal volumes.:D
 
It is mostly alkaline. This is why it cleans up nicely with diluted vinegar or Windex with vinegar. You can see it fizz as the vinegar reacts with the base.
 
Acidic.

From Speer's Education pages:

"In spite of its long service record, black powder has its drawbacks. On combustion in a firearm, less than half the weight of propellant goes into producing gas to propel the bullet. The remaining solids create a big cloud of white smoke and a heavy residue in the barrel. That residue absorbs moisture. Adding moisture to black powder residue creates weak acids that are corrosive to steel."
 
is this all kinda like "Great taste----- Less filling" smiles as to the question.....me i don't know.
 
It's probably easiest to visualize that modern concrete and steel reinforcing systems (rebar) would be impossible if base environments (concrete) caused or accelerated corrosion in iron or steel. On the contrary, alkaline environments affords protection from corrosion. Modern high-rises, bridge structures, and pre-stressed concrete materials, among other things, just wouldn't be economically as feasible it this were true.

From the Concrete Corrosion Inhibitors Association (their conventions are a hoot I bet) website:

"Concrete structures such as bridges and buildings normally contain steel reinforcement. The main benefit is an economical increase of safe load-carrying capacity and ductility for the combination. Thermal coefficients of expansion for steel and concrete are well matched. In addition, we have known for almost a hundred years that the alkaline nature of the surrounding concrete assures protection of the steel from corrosion."
 
Also, fizzing isn't an "acid-base" reaction. Elementary school textbooks have printed that lie for decades, it seems. Baking soda will create CO2 gas when mixed with vinegar, and with some other specific organic acids, but the fact that they're acid and base is almost irrelevant. Baking soda will also react with sodium hydroxide (a very powerful alkaline) to form sodium carbonate and water.

There's really no such thing as a generic "acid-base reaction." For instance, sodium hydroxide + hydrochloric acid at room temp = hot salty water and that's it.
 
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Well...

I'd suggest that if someone really wants to answer that question for themselves... take a pH testing kit and do a test on your spent powder residue, directly off your gun and see what it does.

Off the top of my head... I'd probably reach for some distilled water to keep the "test" as uncontaminated as possible since most any affects to the gun are going to be based upon their exposure to air/moisture/time.

You asked for opinions... here's this half-breed Eskimo's for ya to kick around. :D
 
When the sulpher saltpeter charcoal mix is ignited,it's combustion is incomplete and leaves as residue a weak solution containing, among other things,sulphuric acid.
 
You're all ignoring the potassium. Gunpowder residue is NOT acidic, the pH will be well above 7 (it's about 9.5-10) due to the potassium hydroxide formed.
 
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Black powder contains two sources of ACIDS. When sulfur burns, it forms sulfur oxides. When potassium nitrate burns, it forms various oxides of nitrogen. Both of these classes of compounds like to react with water and when they do, they form primarily sulfuric acid and nitric acid. They also form other acidic forms of sulfur and nitrogen in proportion to the various oxides that each of these oxides form during the combustion of the black powder. In all cases, these oxides will form ACIDS. The reason Windex is a good cleaner is that it contains Ammonia which is a base. The base reacts with the acids to form various salts which are water soluble and can be washed away. What you are doing with the Windex in addition to it's cleaning properties, is to neutralize the many acids which are formed when black powder burns.

So, when black powder burns, it forms large volumes of hot gasses which contain various oxides of nitrogen and sulfur. These oxides combine with water vapor and form ACIDS. When Ginormus runs the litmus test, he will confirm this for you.
 
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Black powder burning isn't quite that simple. Lots of fancy scientists can't even agree on the exact constituents of BP fouling.

One common formula is
2 KNO3 + S + 3 C → K2S + N2 + 3 CO2. No oxides other than carbon.

Another one is
10 KNO3 + 3 S + 8 C → 2 K2CO3 + 3 K2SO4 + 6 CO2 + 5 N2

Still no oxides. Potassium carbonate (a strong alkaline) and potassium sulfate (which is relatively neutral; the SO4- group is acidic, while the 2 K+s are alkaline, and the two components balance each other out).

Of course, both equations are terribly oversimplified, and there probably will indeed be some acidic components. But there will also be potassium carbonate. Who will win? It's a no-holds-barred gladitorial cage match to the death, between K2CO3 and various acidic sulfuric and nitric oxides!
 
Of course, both equations are terribly oversimplified, and there probably will indeed be some acidic components. But there will also be potassium carbonate. Who will win?
Click to expand...

The fact that BP is about 75% KNO3 and only about 10% S gives a pretty clear hint in that direction.
 
There is not enough oxygen in the KNO3 to fully oxidize all the carbon and sulfur, and I doubt the conditions are energetic enough to drive the sulfur all the way to SO3- and not much to SO2- or nitrogen to NOx. The greatest solid product is K2CO3 with some K2S. A lot of the carbon does not go all the way to CO2, forming CO.
 
http://www.civilwarartillery.com/disarm/blackpowder.htm

The products of burning do not follow any simple equation. One study's results showed it produced (in order of descending quantities): 55.91% solid products: Potassium carbonate, Potassium sulfate, Potassium sulfide, Sulfur, Potassium nitrate, Potassium thiocyanate, Carbon, Ammonium carbonate. 42.98% gaseous products: Carbon dioxide, Nitrogen, Carbon monoxide, Hydrogen sulfide, Hydrogen, Methane. 1.11% water
Click to expand...

I don't know if that study burned the BP in confinement or in the open, but in any case, potassium carbonate/K2CO3 is a strong base, and potassium sulfide/K2S is a weak base.
 
Well, I have all the bases covered with only a few dollars worth of lab supplies. The litmus papers will test solely for the presence of acids and/or bases, the universal indicator and pH test paper will determine what the resultant pH actually is with all the lovely goodies combined.

The best part? I get to do a LOT of shooting in the process. :)
 
Man, when this lab supply company means ground, they mean GROUND!

I'm dying on the vine watching the testing components weave it way across the USA to the suburbs of Atlanta:

MEMPHIS , TN , US 07/14/2009 3:06 P.M. DEPARTURE SCAN
07/14/2009 2:19 P.M. ARRIVAL SCAN

LENEXA , KS , US 07/14/2009 5:53 A.M. DEPARTURE SCAN
07/14/2009 2:42 A.M. ARRIVAL SCAN

SALINA , KS , US 07/13/2009 11:31 P.M. DEPARTURE SCAN
07/13/2009 10:33 P.M. ARRIVAL SCAN

COMMERCE CITY , CO , US 07/13/2009 9:07 A.M. DEPARTURE SCAN
COMMERCE CITY , CO , US 07/10/2009 10:09 P.M. ORIGIN SCAN
COMMERCE CITY , CO , US 07/10/2009 7:06 P.M. BILLING INFORMATION RECEIVED

What did I do? Order old inventory from the Rocky Mountain Arsenal? :D
 
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You'll get 'em! Unbiased and with the exact results I receive reported. I've got plenty of Goex and Swiss BP, 777, and some recently acquired Pyrodex P for testing as well.

Testing procedure suggestions are always welcome. :)
 
Science stuff arrived! I guess I need to come up with several pieces of cold rolled flat steel from Home Depot or Lowes. I'm not willing to sacrifice my guns for this test ;)

Well maybe a test with my stainless 1858 Remmie.


DSCF1431.jpg

Stuff to be tested:

DSCF1434.jpg
 
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No need to endanger your guns for the experiment. Actually, all you need is the pHydrion paper strips, they measure pH from 1 to 14 and they won't harm your gun. Here's how to do it: After firing several rounds through your rifle, pour about 1/8 cup of DISTILLED water down the bore and swish it around by tipping your barrel up and down. Don't use a brush or anything down your bore for fear of contaminating the water. Naturally, you will need to plug the touch hole or the nipple (depending on whether it is a flintler or caplock). Use a bit of Saran Wrap to seal off the muzzle so you don't contaminate the water with dirty fingers. Pour off the water into a very clean container that you have previously flushed with distilled water to remove anything that may contaminate the water from your barrel. Pour the water from your barrel into your clean container and test the pH. Before repeating the test for the next propellant, thoroughly clean your bore and rinse several times with distilled water to be sure that all contamination is removed. Run several dry patches through the bore and let it air dry before continuing. If I were doing the experiment, I'd do a set of three times for each propellant to be sure that the results agree and that you have a good measure of the pH of the distilled flush water. Also, be sure that you have carefully measured and documented the pH of the distilled water before doing the experiment. The pH of the distilled water should be exactly 7.0. If it isn't, it isn't pure distilled water and your results will be worthless. Take care in your experiment and you will prevent a lot of arguments when you post the results.
 
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What? Us argue? You sure you've got the right group Bill? :D

You're testing protocol sounds good, thank you. Plus it gives instant gratification. All of my pistols are revolvers, so I'll need to plug the barrel with a non-contaminating cork of some sort. All handling of tested materials will be by nitrile gloved hands. I look good in black rubber. :D

I suggested mild steel plate, as I also intend to burn samples of each propellant on the plate, test the pH initially, and leave the plate exposed to the lovely Georgia humidity, protected from direct rainfall. I will then continue testing each burned sample area periodically over several days for changes in pH.

As always, I'm open to additional suggestions to the second part of the test.

DSCF1436.jpg
 
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