Flashpoint

[Keppy]

I know I have read it here some place. Does anyone have or can steer me in the right direction of a diagram of the flashpoints of diffrent types of powder. Thanks

 

[wszumera]

I think flashpoint is related to vapors eminating from liquids. Not sure flashpoint is the proper term. Maybe ignition temperature would be it.

Check this link:
http://www.musketeer.ch/blackpowder/recipe.html


Clutch

 

[paulvallandigham]

Flashpoint is the temperature at which a substance ignites, generally at sea level. As you go up in altitude the flash point rises, simply because the pressure drops and the percentage of oxygen in the air begins to fall. Its not a significant drop, and the sea level flashpoint can be used for all pratical purposes. I do not know of a general work that compares flashpoints of powders. You can call Goex, and talk to their staff. They know the flash points of their powders, including the new Pinnacle which they redesigned to have a lower flashpoint to be used in Flintlocks. Perhaps Mad Monk has data on the rest of the substitutes, and other black powders, as he has tested many of themfor Goex.

 

[Mad Monk]

I don't think it would be accurate to describe ignition as related to a flash point.

Hodgdon Powder Company looks at the ignition temperature of their powders (Pyrodex and 777) using a hotplate and a pyrometer. They drop a granule onto a hot plate. Watching for instant ignition. The hot plate's surface is not uniform in temperature. So they move around on the surface to find the temperature at which the granule ignites upon contact with the plate. Their MSDS data gives 650 F as the ignition temperature of their subs.

Black powder has a lower ignition temperature. Usually given as around 350 F. The ignition temperature of black powder is somewhat effected (not affected) by the charcoal ingredient. Higher fixed carbon chars require higher temperatures to ignite.

One thing about bp and the subs. If you place some in a little pan on a cold hot plate and then turn the hotplate on to heat up you will see a point where the powder grains appear to melt and then bubble. Giving no ignition of the powder. This is seen in the open.

For ignition they need a quick heating of some portion of the surface of the grain or grains.

One of the Aberdeen Proving Ground papers gives a vivid description of what they saw in bp grain ignition using high-speed photography.

 

[Keppy]

:redface: Yes you are right about that. I will check that out. I thought black powder ignited at 350 degree or something like that. Thanks to all

 

[MikeFromON]

Some sites I have looked at say black powder ignites at 400 deg F, and others say 400 deg C (which is about 680 deg F), and one site said both!

 

[paulvallandigham]

Paper burns at 451 degrees Fairenheit, so I have to believe that BP burns at the 400 Degrees Fairenheit temperature, as it certainly is easier to get it burning with a flint and steel than paper.

 

[Pork Chop]

I guess it depends on if you are shooting european made or US made powder, eh? :rotf:

 

[Mad Monk]

Paper is wood fiber.

When you char wood the ignition temperature of the wood drops as it is being charred. It hits a low point and then as the fixed carbon level increases the ignition temperature of the char rises.

Old homes where wood floor joists rested in notches in the fireplace chimney are noted for fires. The end of the floor joist resting against the hot stones/bricks is slowly sort of toasted. A very slow wood charring process. A point is reached where the ignition temperature of the wood is down around 250 to 300 degrees.

The French played with this back in the mid-1800's in charcoal destined for black powder. The results sort of scared them.

This playing with charcoal properties showed up in 19th century powder plant writings.
Sporting powders are prepared with charcoal made to a 65% fixed carbon content. A redish brown charcoal. Easy to ignite and fast burning. The other end is charcoal for cannon powder. Wood charred to close to 90% fixed carbon content. Difficult to ignite, requiring a high ignition temperature and then only slow burning in the powder combustion.

The extreme end of this is graphite. graphite being pure carbon. It does not ignite until 2000 degrees and then burns only very slowly.