I would seal them tightly in a bag so no moisture can ger in. Then when you go to fly them I would disassemble and replace the o-rings with new ones.

Edward

Edward's got a lot more experience than me on this, but my experience (at least in Colorado's excessively dry climate) is the motors will be fine. I've flown multiple Aerotech blue thunder motors (29mm) that had been stored fully assembled for more than 10 years. With other propellants or higher humidity, I think they would have been toast.

Edward, are AMW's formulations more prone to oxidation or swelling? If so, the ziploc or better yet, foodsaver vacuum sealed bags would be perfect for storage.

-Ken

Most propellants will swell slightly and pick up moisture. Replacing the o-rings is just cheap insurance against them swelling or becoming deformed during storage - especially if the grease used is not 100% compatible with the elastomer. For a flight that day it would be fine, but long term it could degrade the elastomer. I have seen both silicone and buna-n o-rings swell over a prolonged period of time.

Everything you ever wanted to know about o-rings is in this book:

http://www.parker.com/literature/O-Ring%20Division%20Literature/ORD%205700.pdf

It has a compatibility chart for elastomer materials and fluids in the back.

Edward

Thanks for the info. guys. Can you purchase just o-ring kits from the motor mfg's? If the grains have oxidation going on what will it look like?

I have extra o-rings that will fit 54mm and 75mm - let me know and I can get them to you before your flight.

Usually white crystals appear on the surface of the propellant. You sand that off and you will be fine.

Edward

Thanks Edward. I will look you up for those o-rings. I have two new rockets, one using an M motor and the other is a two stage 54 mm motors on it so I do not want to jeopardize their maiden flights with this long delay to launch. How about Nitrous Oxide does it have a "shelf " life in the storage tank?

Nitrous doesn't have a shelf life that I know of. I generally go through about 150# in a year so it doesn't sit around long. I have had a 20# tank sit around for 6-9 months. Still works fine as long as no contamination gets into the cylinder.

Edward

My day job requires that I keep abreast of GHG issues,,, and nitrous is a powerful GHG - with a global warming potential 310 x that of carbon dioxide. A contributing factor is its persistence in the atmosphere - each molecule has an average life in the atmosphere of 120 years. Don't know how storage under pressure affects that, but it certainly would be less exposed to photo-chemical reactions in a bottle.

TMI, I'm sure - bottom line, I'm guessing shelf-life shouldn't be a concern for mere mortals.

Nitrous Oxide has an indefinite shelf life. It is bottled in over-size CO2 type cartridge in several sizes for use in whipped cream dispensers and elsewhere. Once it is packaged and sealed, there is no reaction taking place and it is stable with a long shelf life, just like CO2. Heat it up to a higer temperature of 500 degrees or more and it is a whole new situation that could be explosive. It liquifies and remains in that state near 900 psi, so can easily be stored in a high pressure container. And in comparison to SCBA, SCUBA, CO2, and other pressure containers, it is really a low pressure compared to thier 2800 to 4500 psi.