I have often been told to store primers, primed brass, and powder indoors to avoid exposure to humidity. Many of the same people telling me this have their reloading benches in their garage. Now in my experience here on the Texas Coast, objects tend to form condensation rather quickly when you take them from a climate controlled indoors to a hot and usually muggy outdoors (or garage). These people seem to have no problems with their own reloads which leads me to wonder just how detrimental is the ambient humidity (usually 80-90%)? Is it really so bad to store powder and primers in the garage, or is it a theory that people are afraid test? Does anyone out there have actual experience with misfires or otherwise that can be directly attributed to humidity exposure of components prior to assembly?
- Thread starter Varmint_Poontang
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Tag, very interested in this discussion. Seems like I recall hearing that lead free primers are more sensitive to moisture?
I've got some primers I need to store (not LF) and I was wondering about vacuum packing with dessicant packs
I've got some primers I need to store (not LF) and I was wondering about vacuum packing with dessicant packs
VP,
Yes, it really is that bad. Powder longevity is determined largely by storage conditions. Temperature swings, especially trending towards the high extremes, will degrade powders. CIP officially lists powder shelf life as 10 years. We've probably all used powder, ammo, or both that were far, far older than this with no problems at all. But that's probably the rough average of when you'll start seeing problems come up, especially if the powder was stored improperly, and subjected to major temperature swings. As for humidity, ALL powders are hygroscopic, and will absorb moisture. While this doesn't always mean the powders will start degrading (virtually all powders are washed in water to remove certain solvents and acids used to produce them) they have to undergo a drying process to become usable. What you'd likely be running into here is a situation where the weight of the powder itself will change as it absorbs moisture. Since we generally charge by weight (or at least adjust our measures to a specified charge weight with the aid of our scales), you'll be dealing with charges which are now "weaker" than they should be, if the powder had the correct, lower moisture content.
Pretty much the same observations apply to primers as well. Primers actually require a certain degree of moisture to function properly, and I have heard of misfires being caused by primers being stored in sealed ammo cans with too much desiccant. Literally dried them out too much, and they began misfiring badly. Same primers left out in the open for a time (don't recall how long, sorry) began performing normally after they were "rehydrated" to some degree.
Yes, it really is that bad. Powder longevity is determined largely by storage conditions. Temperature swings, especially trending towards the high extremes, will degrade powders. CIP officially lists powder shelf life as 10 years. We've probably all used powder, ammo, or both that were far, far older than this with no problems at all. But that's probably the rough average of when you'll start seeing problems come up, especially if the powder was stored improperly, and subjected to major temperature swings. As for humidity, ALL powders are hygroscopic, and will absorb moisture. While this doesn't always mean the powders will start degrading (virtually all powders are washed in water to remove certain solvents and acids used to produce them) they have to undergo a drying process to become usable. What you'd likely be running into here is a situation where the weight of the powder itself will change as it absorbs moisture. Since we generally charge by weight (or at least adjust our measures to a specified charge weight with the aid of our scales), you'll be dealing with charges which are now "weaker" than they should be, if the powder had the correct, lower moisture content.
Pretty much the same observations apply to primers as well. Primers actually require a certain degree of moisture to function properly, and I have heard of misfires being caused by primers being stored in sealed ammo cans with too much desiccant. Literally dried them out too much, and they began misfiring badly. Same primers left out in the open for a time (don't recall how long, sorry) began performing normally after they were "rehydrated" to some degree.
Interesting, KST, I never considered the weight of the powder, I always assumed that moisture would cause a more chemical form of degradation. Would desiccation reconstitute improperly stored powder?
This is a whole different tangent than what I envisioned when I initially created this thread, I guess I was not specific but I was thinking more along the lines of "I had some primers and powder in my garage for six months, should I toss it or use it?" Nonetheless, this thread is still viable and the future responses ought to be good. Thanks.
This is a whole different tangent than what I envisioned when I initially created this thread, I guess I was not specific but I was thinking more along the lines of "I had some primers and powder in my garage for six months, should I toss it or use it?" Nonetheless, this thread is still viable and the future responses ought to be good. Thanks.
VP,
The long term degradation could become an issue over time, but it's the temperature swings that really cause the problems. As to the moisture content, yes, if you're ever seen powder being made it starts off as a very moist dough. Literally. Looks exactly like something you're wife or mom would have spread out on a countertop to make biscuits. In the case of extruded tubular powders, that dough gets run through a die, in the same way they make spaghetti or other pasta. Pretty much the same color, too. It's pliable and still very soft at that point. It isn't until it gets cut to length, and run through the various baths and drying cycles that it becomes hard and solid. The final application of coatings is what gives it its final color and arrives at a point where it looks like the powder we all know and love. But yeah, a lot of these production phases take place underwater, or other chemicals, where they absorb some degree of those liquids. Moisture in, moisture out, it's a fairly endless cycle. That's why we store them in the ways that we do. Interesting process, though.
The long term degradation could become an issue over time, but it's the temperature swings that really cause the problems. As to the moisture content, yes, if you're ever seen powder being made it starts off as a very moist dough. Literally. Looks exactly like something you're wife or mom would have spread out on a countertop to make biscuits. In the case of extruded tubular powders, that dough gets run through a die, in the same way they make spaghetti or other pasta. Pretty much the same color, too. It's pliable and still very soft at that point. It isn't until it gets cut to length, and run through the various baths and drying cycles that it becomes hard and solid. The final application of coatings is what gives it its final color and arrives at a point where it looks like the powder we all know and love. But yeah, a lot of these production phases take place underwater, or other chemicals, where they absorb some degree of those liquids. Moisture in, moisture out, it's a fairly endless cycle. That's why we store them in the ways that we do. Interesting process, though.
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