powder in the pan ignites powder in chamber

[N.Y. Yankee]

It's the "fire", from lighting the priming charge with sparks, that goes through the touch hole and ignites the main charge. Whether it is actually sparks getting through (I doubt it) or flaming hot gasses or both, I'll never know for sure but I like to believe it's the hot gasses from the flare up that does the trick.

 

[TrapperPete]

spark or heat makes little difference what you are NOT doing is fusing through the flash hole that works but is the wrong way to get fast ignition.
this is why many keep a pick through the flash hole while they carry it pull the pick so that there is an open path and not a fuse.

 

[Henry Miles]

The fire from the priming charge makes direct contact with the main powder charge. Easy to understand how that would work. Makes sense about placing the priming charge away from the touch hole to give an airgap for the flare up to occur. Thanks for the input!

 

[Many Klatch]

we tested this once. 10 of us loaded blanks and did not prime. We all pointed at the sky, cocked the lock and pulled triggers at the same time. 1 gun went off much to our surprise. We did this 3 times, each time 1 gun (different) went off. So you have a 1 in 10 chance of your gun going off if you don't prime. Bad odds. I don't care if it's radiant heat, or direct heat or sparks or whatever, if you don't prime the gun won't go off reliably.

 

[theC525]

This is a lot of discussion and there are many theories on this subject. It is my understanding that;
It is NOT a "fused effect" from priming powder that sets off the main charge, rather the heat from the burning powder going through the touch hole that sets the gun off. However, IMHO, after building these rifles for some years now I will tell you this. Your fastest ignition will come from a smaller charge in the pan... as long as you have placed the touch hole in the correct relation ( as far back in the breech as possible, center of barrel flat, top dead center of the pan) to the lock pan.

 

[Art Caputo]

The priming charge in the pan is set off by the direct contact of the powder and the spark coming together. If they don't touch, the powder doesn't ignite. In the same way, ***if the priming charge goes off but doesn't make contact with the main charge, it's a flash in the pan. Heat alone is nothing without direct contact with the powder.***

Respectfully, yes, the molten metal from the flint striking the frizzen ignites the pan charge, but, high percentage of ‘flash in the pans” is the result of residue blocking the flash channel. When the “priming charge goes off”, the heat from the fireball(gases/burned solids) produced from the priming charge is propelled down the flash hole concentrating heat to the main charge. Heat at sufficient temperature is the only thing responsible for the ignition of black powder in a flintlock.

 

[theC525]

Respectfully, yes, the molten metal from the flint striking the frizzen ignites the pan charge, but, high percentage of ‘flash in the pans” is the result of residue blocking the flash channel. When the “priming charge goes off”, the heat from the fireball(gases/burned solids) produced from the priming charge is propelled down the flash hole concentrating heat to the main charge. Heat at sufficient temperature is the only thing responsible for the ignition of black powder in a flintlock.

So in other words, keep your hole picked out or your gun won't go off!

 

[Trailblazer451]

If you think about getting burnt by a fire with your hand a foot above the burning fuel, you have your answer. The priming powder does not have to contact the powder in the chamber, but the heat from the ignition does. To burn anything, you need to have air, fuel, and a heat source at the ignition temperature of the fuel.

In other words, it's really the heat, but to achieve the heat, you need to get the adequate spark/flame close enough to the fuel to ignite.

The standard black powder has an autoignition temperature of 464°C. (from Sciencemaddness wiki). If you could put your firearm into the oven at that temperature (867°F - your stock would probably not like that), then the firearm would go off. No spark, no "radiant heat" as you have described it. Environmental conditions would ignite the powder, as it would have fuel, oxygen, and heat - all the conditions required.

Flint and steel spark is supposedly 2498°F .

Dave

 

[BV]

As long as it works, I see no reason to concern myself with how it works.

 

[Art Caputo]

The beauty of black powder is that the requirement for air/oxygen is nil, and taken care of by the inclusion of sulfur in the mixture by design. The sulfer releases sufficient oxegen upon combustion to support the burning/ explosion of the mixture.

 

[Trailblazer451]

The beauty of black powder is that the requirement for air/oxygen is nil, and taken care of by the inclusion of sulfur in the mixture by design. The sulfer releases sufficient oxegen upon combustion to support the burning/ explosion of the mixture.

Actually, according to Wikipedia (and my poor memory, so I look things up), it is the potassium nitrate which supplies the oxygen.

WikiPedia:
Black powder is a granular mixture of

• a nitrate, typically potassium nitrate (KNO3), which supplies oxygen for the reaction;
• charcoal, which provides carbon and other fuel for the reaction, simplified as carbon (C);
• sulfur (S), which, while also serving as a fuel, lowers the temperature required to ignite the mixture, thereby increasing the rate of combustion.

Dave

 

[Art Caputo]

Actually, according to Wikipedia (and my poor memory, so I look things up),
it is the potassium nitrate which supplies the oxygen.


WikiPedia:
Black powder is a granular mixture of

• a nitrate, typically potassium nitrate (KNO3), which supplies oxygen for the reaction;
• charcoal, which provides carbon and other fuel for the reaction, simplified as carbon (C);
• sulfur (S), which, while also serving as a fuel, lowers the temperature required to ignite the mixture, thereby increasing the rate of combustion.

Dave

You are correct. My bad! Had sulfur in my head just having shot my flinter.

 

[Larry Pletcher]

I started this message twice and am not sure I have a good answer. When I think of barrel ignition speeds I tend to think of how I'd tackle timing it. I tend to think of wave of heat vs a wave of fire. In engine ignition they use the term "flame front".

I'm ruling out individual sparks for this discussion. I think of a flame front from the ignited pan traveling in all directions - of course part of which enters the vent. The fire of flame front has a wave of heat traveling in all direction part of which also enters the vent.

Since the flame front is the cause of the wave of heat, it may be logical to assume that the wave of heat travels faster than the flame front. But no body has ever tested that theory.
Can the flame front travel faster than the heat wave?
Can the heat wave travel faster than the flame front?
So the question is which of these variables causes barrel ignition. In test that I have done I use a red hot copper wire to ignite pan powder, so there is no flame front. But I cannot test a flame front and eliminate the heat wave.

So, we're back where we started with no practical way to use a test to solve the problem. We can't prove which arrives first - the heat wave of the flame front. Let's look at this another way. In my lock I make sure some of the prime is against the barrel. I can see barrel powder at the entrance of the vent. There is perhaps 1/16" between the two powders. When the pan ignites and the heat wave and flame front travel to the vent, which will cover the 1/16" first? Can we measure the difference? Does it really matter?

From an experimental standpoint I would answer any strong opinion either way, by saying show me your evidence, citing your testing methods. Human senses do not count.

I'm sure this doesn't provide proof of anything. If someone has the means to measure heat wave vs flame front I'll be all ears.
Regards,
Pletch
PS someone asked, "If heat wave is the answer, why does smaller grain powders ignites faster? Here we're talking about the speed of the pan priming to ignite. Smaller grain sizes have more surface area, and ignition starts on the grain surface. More surface area means faster pan ignition. We can see this in slow motion videos of pan ignition.

 

[flntlokr]

I have been under the impression, that the sparks from the burning priming powder ignited the powder in the chamber. I have experienced keeping the touch hole open and using the minimum of priming powder shortened the delay between, when the frizzen is struck and the gun goes off.

I recently watched a video and it was stated, that it was not the sparks from the burning priming powder that ignited the powder in the chamber, but the radiant heat from the burning powder, that caused the ignition. Will someone care to elaborate on this concept?

Thanks

As many have pointed out,, you can grt ignition with a single spark from the frizzen bouncing into the flash hole. If you are igniting a priming charge that is separated from the main charge, it is the ball of fire from the explosion of the priming blasting in the flash hole that does the job. If you fill the flash channel with powder, you create a 'powder train' fuse that passes the explosion down the line much more slowly than the fireball from the priming exploding. It's sort of like fighting a fire withbuckets of water; fast delivery of the water by just throwing a bucket full from afar, rather than by passing it a glassful at a time down a line of volunteers.

 

[Wild Tim]

This is simple. If it was "radiant heat" we wouldn't need a touchhole. The heat would transfer through the metal through conduction and ignite the powder. It is the flaming powder that flashes through the touchhole and lights the powder charge. If it a flaming solid fuse or a flaming gass fuse it's still the flame not just the heat.

 

[S.Kenton]

Wild Tim in my opinion is correct. also, think about caplocks. The tiny molten ember being forced down through nipple is enough to ignite the main charge... it’s the same principal for flintlocks, in my opinion, it only takes one spark to set it off... once again I’ve not tested it and it’s just my opinion.

 

[olskool]

here are things heating up on my 54 southern rifle before the chamber explodes. this photo was timed just right as the gun goes off instantly. that Bob Roller lock really lights a fire,,,,,,,,,,,,,,,,

 

[TrapperPete]

You are correct. My bad! Had sulfur in my head just having shot my flinter.

correct , home made black powder often leaves out the sulfur component yet works fine.

 

[brazosland]

I started this message twice and am not sure I have a good answer. When I think of barrel ignition speeds I tend to think of how I'd tackle timing it. I tend to think of wave of heat vs a wave of fire. In engine ignition they use the term "flame front".

I'm ruling out individual sparks for this discussion. I think of a flame front from the ignited pan traveling in all directions - of course part of which enters the vent. The fire of flame front has a wave of heat traveling in all direction part of which also enters the vent.

Since the flame front is the cause of the wave of heat, it may be logical to assume that the wave of heat travels faster than the flame front. But no body has ever tested that theory.
Can the flame front travel faster than the heat wave?
Can the heat wave travel faster than the flame front?
So the question is which of these variables causes barrel ignition. In test that I have done I use a red hot copper wire to ignite pan powder, so there is no flame front. But I cannot test a flame front and eliminate the heat wave.

So, we're back where we started with no practical way to use a test to solve the problem. We can't prove which arrives first - the heat wave of the flame front. Let's look at this another way. In my lock I make sure some of the prime is against the barrel. I can see barrel powder at the entrance of the vent. There is perhaps 1/16" between the two powders. When the pan ignites and the heat wave and flame front travel to the vent, which will cover the 1/16" first? Can we measure the difference? Does it really matter?

From an experimental standpoint I would answer any strong opinion either way, by saying show me your evidence, citing your testing methods. Human senses do not count.

I'm sure this doesn't provide proof of anything. If someone has the means to measure heat wave vs flame front I'll be all ears.
Regards,
Pletch
PS someone asked, "If heat wave is the answer, why does smaller grain powders ignites faster? Here we're talking about the speed of the pan priming to ignite. Smaller grain sizes have more surface area, and ignition starts on the grain surface. More surface area means faster pan ignition. We can see this in slow motion videos of pan ignition.

Fine grain powders have more surface area, per volume, to combust per unit of time.

Same reason 3F gives higher pressures and velocities than 2F.

 

[brazosland]

This is simple. If it was "radiant heat" we wouldn't need a touchhole. The heat would transfer through the metal through conduction and ignite the powder. It is the flaming powder that flashes through the touchhole and lights the powder charge. If it a flaming solid fuse or a flaming gass fuse it's still the flame not just the heat.

To use an extreme example...Nuclear Detonation...heat travels faster than flame.

Heat is a radiation. The flame front is a physical combustion that travels at the speed it is able to manifest itself.

Radiant Heat is the Way.