Powder clumping?

[rich pierce]

In the field I was reloading and pouring FFG Goex powder from my big horn into a charger and nothing was coming out. I shook the horn violently and the problem remained. I eventually got enough powder out. The big horn was 1/3 full. Luckily I did not need to shoot again immediately. Later I explored tgd issue and there was a clump of powder grains about the size of a housefly. Thankfully not a horsefly!  I’ve not experienced this before. Have you?

[MuskratMike]

I have always been in the habit of shaking my horn several times before I put it over my shoulder. Just the way I was taught. I imagine if you live in warm humid climate this "clumping" could be a problem, but I have never experienced it. I also leave my horns and bags hanging on a rack in an unheated garage/shop space. Bringing them in and out of a heated space might also contribute to the problem. Just some thoughts.

[smallpatch]

Rich,
I live in Arizona.  NOTHING clumps here with single digit humidity.

[Daryl]

Had it happen once, Rich, in a horn I didn't use for many years. It still had some powder in it, and when I poured the powder out, to change it, I had a blockage, just as you describe, Rich.
I surmised we had a moist period in which that horn was present, perhaps on the trail. As I only used that horn with a particular rifle I hadn't used for quite a while, I experienced the
clumping. This is not a normal occurrence here that I am aware of.
Now, I do as Mike noted, I shake the horn before putting it on, to see/hear/feel how much is inside, as well as to break up any "clumps".
The keg of American Deadshot FFG powder I acquired back in the 70's had a few larger powder clumps in it.  These were easily broken up. As well, there were some small clumps of rust in the
 powder, which were quite easily removed, as well. This was from the inside of the can/keg, so I transferred the powder to GOEX cans.  It was in a 10 pound keg, having perhaps 3 to 4 pounds
 remaining, of powder. Best powder I ever used, as well. The granules were black, sharp cornered, extremely hard and shiny - no dust. It was very nice looking powder too, that was approaching
 100years old.

[Mad Monk]

In the field I was reloading and pouring FFG Goex powder from my big horn into a charger and nothing was coming out. I shook the horn violently and the problem remained. I eventually got enough powder out. The big horn was 1/3 full. Luckily I did not need to shoot again immediately. Later I explored tgd issue and there was a clump of powder grains about the size of a housefly. Thankfully not a horsefly!  I’ve not experienced this before. Have you?

The question here is how old is that GOEX.  Look at the printing on the bottom of the can.  That code will tell when it was packed.  Date, month and year. 
Some lots of powder out of the old Moosic plant were noted for clumping thanks to the fertilizer grade of potassium nitrate used to make it.  The grains surfaces would pick up enough moisture to produce that clumping.  Usually a good coating of graphite on the powder would stop that.  Graphite has been used to act as an anti-blocking agent in black powder made to be used in high humidity areas.  This clumping is somewhat typical of all crystaline materials.  The small crystals simply want to join together and form large crystals.  After GOEX moved to Minden they had to change potassium nitrate suppliers from one in the U.S. that shut down to potassium nitrate produced in Chile.  The potassium nitrate from Chile had no traces of sodium nitrate in it so it is fairly immune to water in the air.

When you go back before the mid-1800s you see the various military groups pulling the wooden kegs of powder out of the magazines and rolling them around on the ground and then putting them back into the magazine.  This was to break up any clumps formed in the powder.  But that was the days before they realized high-purity potassium nitrate was a must and proper polishing and glazing would help stop that clumping.  But these days with the present powder production that clumping is very rarely seen except in partial cans of powder that had been opened and used during periods of high humidity that left a lot of very moist air trapped in the can.

[Mad Monk]

I forgot to mention that sometimes powder horns do not give a good air seal with long periods of not being used.  Every now and then I would check the edges of the wood plugs and force some beeswax into the seams.  Watch the horns with the throat staples for the horn straps.  Sometimes a little beeswax around where the staples enter the horn if the staples go through the horn body before being bent over.  Same with the wooden plug used to close the tip.  The wood breathes with the grain which allows moisture to be carried from one end of the plug to the other.

The horn body is rigid.  When the atmospheric pressure changes you will have small amounts of air pulled into the horn and also pushed out of the horn.  The powder grains act as a desicant in the horns.  So any moist air being pulled into the horn will be expelled as nearly dry air.  The horn simply cannot flex during these air pressure changes.
 

[rich pierce]

Thanks guys. This Goex is pretty recent- plastic 1 pound “can”.  I tossed the can, so cannot check the date. I just put the whole thing in my horn at once and toss the can. I’m going with the humidity possibility.

[ScottH]

I think it means you don't shoot enough 

[rich pierce]

Ha, 6th pound this year. More than last year.

[alacran]

Like Smallpatch I don't worry about it when I' home in Arizona. When I'm in the Midwest I do not leave powder in the horns. I dump it back in the can.

[P.W.Berkuta]

I have an early horn that I made MANY years ago that I seldom use. It was about 1/3 full of old GOEX or DuPont. It had clumps in the powder when I shook it. I used a wire to break up the clumps and emptied the horn. At that time I was living in NJ.

[hanshi]

I've never had a clump form in a horn that plugged the spout; but I've seen a small clump here and there when pouring from a can.

[Mike from OK]

I was shooting last week and had a similar issue. I have a small horn of Goex OE 3f. I noticed it wasn't pouring as easily as normal. Gave the horn a light shake and could feel a decent size clump thumping around in the horn. A few more vigorous shakes remedied the issue... First time I've ever had that issue in a horn. I have had a few clumps in the plastic container a time or two... Usually after I break the seal and it sits several months before I open it again.

They break up easily enough that I never paid it much mind.

Mike

[Jeff Murray]

In addition to using bees wax around the horn plug, you might check the fit of your stopper.   Wood will dry and shrink over time if it is not sealed/oiled. It will also swell and shrink with major humidity changes just like a ramrod. Your stopper may not be air tight if it has dried out.  I also make my stoppers with a longer plug shaft that is slightly tapered so it has a tight fit at the spout.  submerge it in a bucket of water to see if the tip of the plug or the inside of the horn take water.