Priming powder location in the pan

[ApprenticeBuilder]

There's no fly in the ointment at all...you're missing the point of the experiment

Not so much.

Fire creates its own wind, said wind needs an open path for the flame to follow, with a closed system the results most likely would be different. I don't think the flame enters the flash hole at all on a closed system, transference of heat is the most likely source of ignition. By piling the prime closer to the barrel I see a more rapid build-up of fouling at the vent more than annythig else. :hmm:

Just my observations based on limited experience.

 

[Larry Pletcher]

OK, this pretty well exhausts my ideas about using pics to see what happens in the pan, vent, and barrel. In these stills you can make comparisons about the amount of priming and where the priming is located. It doesn’t address speed, although I’d almost be willing to speculate ”“ but won’t. The computer timing will come later, measuring time from pan ignition to gases exiting the stub barrel. I need milder weather because of the amount of smoke. I can get away with pan powder in my basement, but not barrel powder added on.


These photos use Paul’s suggestion with a dark background behind the fire. Thanks, Paul; it worked very well. The same camera methods were used, although I had a better chance to focus for distance.

Pan is primed with .5 gr Swiss away from the vent

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Pan is primed with .5 gr Swiss close to the vent.

(BTW the stick-like object in these first two pics is the copper wire used to ignite the pan. From here on it doesn't show - covered up by the pan ignition.)
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Pan is primed with .5 gr Swiss very close to the vent

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Pan is primed with 1.0 gr Swiss away from the vent

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Pan is primed with 1.0 gr Swiss close to the vent

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Pan is primed with 1.0 gr Swiss very close to the vent

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Pan is primed with 2.0 gr Swiss away from the vent

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Pan is primed with 2.0 gr Swiss close to the vent

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Pan is primed with 2.0 gr Swiss very close to the vent

Looking over these pics, the 2.0 gr charges didn't improve fire inside the barrel much as Paul and I discussed. In fact, the 1.0 gr.charges look hotter to the camera. In this test I did not do 1.5 gr because we did that earlier. I do need to say that when priming the very close charges I tried to get the powder as close to the vent as possible without covering it. When using 2.0 gr I had a powder pile higher than the hole, and used a vent pick to move part of the charge away.

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Apprentice Builder brings up the question:
The only fly in the ointment here is the fact that you are essentially testing an "open air system", there is no charge or clean-out screw in the barrel which I feel would seriously affect the results. ??
This is where computer timing comes in. I simply can’t deal with all the variables with the camera. When using the computer, we will have a charge in the barrel, the cleanout will be closed, and we will be dealing with numbers instead.

Regards,
Pletch

 

[paulvallandigham]

The fire doesn't enter the barrel and powder charge? Really? Take a percussion shotgun or rifle, empty of powder and ball or shot, and put a fresh cap on the nipple. This is then a " closed system, except for the bore and muzzle which are open. Now take it outside at night, or into a closed garage with the lights off, and fire the cap. Keep your eye on the muzzle and tell me there is no " fire " coming out the muzzle! If that fire comes out the muzzle, its reasonable to assume that the fire also enters the powder charge when one is in the barrel in line with the flash channel from the nipple when a cap is fired on it.

Now, on a flintlock, the fire is NOT injected into the powder. That is why I recommend using a pick to make a hole in the powder charge after the PRB is seated, and before you prime the pan. The hole allows the fire to enter the barrel, where the heat will ignite several or many different granules of powder all at the same time. Instead of one granule of powder blocking the vent hole being ignited, and hopefully igniting another granule behind it, -- a fuse like ignition-- you get multiple fuses all doing a chain reaction at the same time, and pressure quickly builds in the flintlock to fire the PRB out the muzzle.

 

[Leonredbeard]

Pletch,
I have been wanting to see that for some time now.
:bow: :grin: :applause: :shocked2:
volatpluvia

 

[Sherlock]

There is an easy way to see if powder gas or particles enter the touchhole of a barrel simulating a loaded charge. In your spotlessly clean barrel, push a damp, almost wet patch down to the bottom on a jag and allow it to rest there, carefully prime as normal, taking care to exclude powder from the flashhole. and drop the cock. the damp patch will tell you about particle entry by catching grains. That's the particle part. For the gas part, start clean and dry and push a small toilet paper patch down there. You can hardly separate radiant energy from gas and particles, but the tp will suggest what happened too. Wonky

 

[ApprenticeBuilder]

The fire doesn't enter the barrel and powder charge? Really? Take a percussion shotgun or rifle, empty of powder and ball or shot, and put a fresh cap on the nipple. This is then a " closed system, except for the bore and muzzle which are open. Now take it outside at night, or into a closed garage with the lights off, and fire the cap. Keep your eye on the muzzle and tell me there is no " fire " coming out the muzzle! If that fire comes out the muzzle, its reasonable to assume that the fire also enters the powder charge when one is in the barrel in line with the flash channel from the nipple when a cap is fired on it.

This has absolutly nothing to do with the tests and results obtained here, caplocks are a forced system.


Make no mistake, I am in awe of the trials that Pletch has undertaken. I will be very interested in the time trials as that will tell a most interesting tale.

 

[flaming canvas]

Larry: Its clear that fire seeks oxygen, and it will go for oxygen in the barrel if the fire is lit near the touch hole.

Remember that 3/4 of the volume of black powder is a nitrate, the source of oxygen in the reaction. BP does not depend on atmospheric oxygen to ignite. If it did, it wouldn't be useful as a propellant in a closed chamber where oxygen is absent.

I think the pictures are showing the actual flame from the burning priming charge. An earlier post alluded to something resembling the Bernoulli effect if the charge were placed next to the touch hole, that the gases would blow by the touch hole rather than entering. The explosive expansion of the gas produced by the priming charge will happen in all directions. What would be interesting would be to plot the directions of the individual grains of powder in the prime as the entire amount burns. It seems reasonable to me that the much of the charge will be agitated and the grains will be lifted off the bottom of the pan by the relatively early portion of the burn and actually burn in the space above it. This must be true when a flintlock is fired upside down since the prime will be resting on the frizzen, but the gun will still fire.


Pletch,

An excellent exploration. I look forward to seeing any other results you may come up with.

 

[Larry Pletcher]

. . . . This must be true when a flintlock is fired upside down since the prime will be resting on the frizzen, but the gun will still fire. . . . .

It actually works a little different than that. In a high speed video of a large Siler, the lock was fired up-side-down and filmed at 5000 fps. When the frizzen snapped open, the priming powder was left in its original position and then began its fall (kind of like yanking your hand out from under a ping pong ball.) The prime then actually fell into the sparks as they were being driven upward. The prime manages to fall maybe a mm or two before ignition takes place.

Regards,
Pletch

 

[flaming canvas]

Exactly my point, Pletch. The powder is not in the bottom of the pan and the fireball expands in all directions

 

[paulvallandigham]

Flaming Canvas:

Fire is a greedy mistress, and she will take oxygen anywhere she can get it. That is why using bellows to increase the temperature of a fire over that which it makes, whether burning wood, coal, and various gases works. The more air the fire gets, the hotter it burns. If it rejected " free air ", and ONLY relied on the Oxygen it has within its own molecules, bellows would not achieve any increase in temperatures.

The same holds true for gun powder. Yes, the Black Powder molecules have oxygen within them sufficient to provide all the O2 that is needed for it to burn IN A VACUUM.

But in the air, we see it will take air from the nearest locations to the hottest parts of the flame. Since gravity pulls equally on all matter, a flame should be drawn downward. But in Air, fire goes up as the air around it is heated and rises. As the air rises, so does the flame. The result it that cold air comes to the flame from the bottom of the flame, where rising air creates a temporary vacuum that needs to be filled.

Air available on the side of the flame will DRAW the flame over to it, simply because it is available and does not interfere with the heat of the flame wanting to rise.

The trick is to put the hole you want to get heat into from any flame to the side, above, or both to the side, and above the base of the fire.

 

[Claude Mathis]

Flaming Canvas:

Fire is a greedy mistress, and she will take oxygen anywhere she can get it. That is why using bellows to increase the temperature of a fire over that which it makes, whether burning wood, coal, and various gases works. The more air the fire gets, the hotter it burns. If it rejected " free air ", and ONLY relied on the Oxygen it has within its own molecules, bellows would not achieve any increase in temperatures.

The same holds true for gun powder. Yes, the Black Powder molecules have oxygen within them sufficient to provide all the O2 that is needed for it to burn IN A VACUUM.

But in the air, we see it will take air from the nearest locations to the hottest parts of the flame. Since gravity pulls equally on all matter, a flame should be drawn downward. But in Air, fire goes up as the air around it is heated and rises. As the air rises, so does the flame. The result it that cold air comes to the flame from the bottom of the flame, where rising air creates a temporary vacuum that needs to be filled.

Air available on the side of the flame will DRAW the flame over to it, simply because it is available and does not interfere with the heat of the flame wanting to rise.

The trick is to put the hole you want to get heat into from any flame to the side, above, or both to the side, and above the base of the fire.

It kind of makes you wonder how the old-timers did it, not knowing any of this stuff? It's a wonder they even got their guns to fire. :wink:

 

[paulvallandigham]

Actually, I think the oldtimers DID understand all this better, because they cooked and heated their homes with wood fires all the time. They understood fire better then, than we do now, simply because we have gotten so far away from it, we no longer understand it. Most people are surprised, for instance, when I have them look hard at a candle flame to see that there is an empty space of air in the middle of the flame. Until its pointed out to them, they don't see it.

I find the same thing concerning tracking. Everyone tracked in the old days, because that is how you closed on game to be able to eat. Today, we hunt only for pleasure, and tracking is unknown knowledge to 99% of hunters. Many scoff at the idea that a modern man can follow tracks or read sign. Hlaf the people who read this won't have a clue what I am talking about. Sign? What's that?

 

[Rebel]

I know, i know, i saw deer sign just the other day as i was traveling down the highway. It said "DEER CROSSING"

 

[flaming canvas]

My thoughts,

I don't think that fire can actively seek oxygen. True, it will consume what oxygen it encounters, but the actual amount of oxygen within the volume of the
fireball of the priming charge is small compared to that generated by the kno3 in the powder itself. The atmospheric oxygen will be on the outer surface of the fire and pushed away by the waste gases of the burning reaction. During the short timespan of combustion a draft cannot have much time to circulate oxygen to the powder. The amount of oxygen confined between the grains in a charge of powder and under the ball in a load is negligible for the reaction.


Since the flash is visible inside the barrel, I now wonder if the light we see is from high temperature incandescent gases, byproducts of the combustion of the blackpowder, or if there are microscopic particles still burning inside the barrel, having been carried in with the expanding gas cloud.

 

[roundball]

I don't think that fire can actively seek oxygen. True, it will consume what oxygen it encounters, but the actual amount of oxygen within the volume of the fireball of the priming charge is small compared to that generated by the kno3 in the powder itself. The atmospheric oxygen will be on the outer surface of the fire and pushed away by the waste gases of the burning reaction. During the short timespan of combustion a draft cannot have much time to circulate oxygen to the powder. The amount of oxygen confined between the grains in a charge of powder and under the ball in a load is negligible for the reaction.

Exactly...same reason good quality firecrackers with waterproof fuses still work perfectly when tossed in the water...they generate all the oxygen they need.

Same with blackpowder in my bores...I intentionally compress a main charge so hard I can hear it crunch and if my ignition was any faster I couldn't stand it. My charges are compressed so hard that occasionally I'll bloop one out with compressed air and it'll hold together as a single pellet...which by the way makes me think that's exactly how the idea was spawned to make BP substitute powder into pellets.
:thumbsup:

 

[Larry Pletcher]

. . . . . Since the flash is visible inside the barrel, I now wonder if the light we see is from high temperature incandescent gases, byproducts of the combustion of the blackpowder, or if there are microscopic particles still burning inside the barrel, having been carried in with the expanding gas cloud.

Flaming C
You pose a good question. I try to avoid speculating, and have no concrete evidence. My thought is based on what we DON'T see. In other high speed video I did, when a single particle ignited one could pick it out in the video. Here the gases appear to lack any particles. So I would suggest that we're seeing incandescent gases after particles are consumed. This is opinion only based on NOT seeing something instead of seeing something. I bet this is pretty tough to prove either way - so maybe I'm safe :grin:

OK,OK, I promise not to speculate without numbers any more. :grin:

Regards,
Pletch

 

[roundball]

Here the gases appear to lack any particles. So I would suggest that we're seeing incandescent gases after particles are consumed.

I agree and my personal belief that this is similar to what ignites the main charge, independent of physical flaming particles, and possibly independent of physical flame.

Like holding your finger an inch above the end of the visible flame of a candle...you can't see that invisible layer of heat with the naked eye but it'll obviously burn your flesh in a heart beat.

 

[flaming canvas]

. . . . . Since the flash is visible inside the barrel, I now wonder if the light we see is from high temperature incandescent gases, byproducts of the combustion of the blackpowder, or if there are microscopic particles still burning inside the barrel, having been carried in with the expanding gas cloud.

Flaming C
You pose a good question. I try to avoid speculating, and have no concrete evidence. My thought is based on what we DON'T see. In other high speed video I did, when a single particle ignited one could pick it out in the video. Here the gases appear to lack any particles. So I would suggest that we're seeing incandescent gases after particles are consumed. This is opinion only based on NOT seeing something instead of seeing something. I bet this is pretty tough to prove either way - so maybe I'm safe :grin:

OK,OK, I promise not to speculate without numbers any more. :grin:

Regards,
Pletch

I kind of enjoy speculating. Makes an interesting intellectual exercise.

For end products I would guess that we are getting carbon monoxide and dioxide, sulfur dioxide and potassium nitrite. Have to ask the chem teacher at school if she can give any insight on temps that would produce the glow from the last two.

 

[worker11811]

Don't forget! Even if there were burning particles you might not see them in the picture. They might have been lost in the blur. Even at 1/500 of second you might get blur if the particle(s) move fast enough.

 

[Dphar]

Same with blackpowder in my bores...I intentionally compress a main charge so hard I can hear it crunch and if my ignition was any faster I couldn't stand it. My charges are compressed so hard that occasionally I'll bloop one out with compressed air and it'll hold together as a single pellet...which by the way makes me think that's exactly how the idea was spawned to make BP substitute powder into pellets.
:thumbsup:

How do you do this?
From testing shows it takes a LOT of pressure to form a slug as you describe. Enough to break a wrist on a longrifle.
I have never been able to significantly compress well settled powder over about 1/16" with my bare hands.
Keeping it together while being blown down a bore would require over 1000 PSI, probably 3000+ psi at the face of the powder based on compressing powder in a steel chamber with a arbor press. In most calibers this would require 400 pounds of pressure on the rod *minimum* to do this.
Now if the powder is wet by oil, patch lube or some other ingredient it is possible to make it form a plug close to the point of mild compression but not likely the entire charge.

Dan