Powder Storage

[MudRunner2005]

I store all my reloading components inside a storage container in the house, in my reloading room. This way it does not degrade, and the temp stays stable year-round (63º-68ºF) with virtually no atmospheric moisture.

 

[MagnumManiac]

Funny thing regarding moisture, did you all know that IMR have a large container filled with IMR 4895 from the very first batch IN WATER that they periodically take out a pound, dry it out and test it alongside a new batch to see how the 2 compare?
I believe Olin have 748/760/296/780 all stored in a similar manner.
True story!

Most powders, not all though, are virtually waterproof due to all the deterrent coatings, additives and type, Double Base powders will NOT change their moisture content due to air moisture, but like all powders, they start to degrade if let to get very hot then cold then hot again.

Cheers.

 

[Hatrick]

Most powders, not all though, are virtually waterproof due to all the deterrent coatings, additives and type, Double Base powders will NOT change their moisture content due to air moisture, but like all powders, they start to degrade if let to get very hot then cold then hot again.

Kind of like beer and wine!

 

[kiwikid]

According to an article in the Norma reloading manual written by Sven-Eric Johansson, the former head of ballistics at Eurenco/Bofors Double Base powders will indeed increase in moisture content if the relative humidity increases. In a graph on page 113 of the manual it shows a double base powder with a 12% nitroglycerin content. At 30% RH it would have slightly more than 0.2% moisture content but if the RH is increased to 90% the powder will have just over 1% moisture content. Double Base powders certainly don't change as much as Single Base but they do change. The Norma manual has a great deal of info on the effects of temperature and humidity on the various types of powder.
Kiwikid.