Time between motor build and launch?

So, I built up a few AT 75mm motors in April for a planned launch. I used one of them (M1500G), but didn't have time to use the L850W.

What is the recommended best practice for storing built-up motors? And do you risk degradation of the motor in any way, e.g., due to humidity? Clearly, if the motor is bonded into the phenolic liner, there is no way to put the grains back into sealed bags.

Anyway, I used the L850W this past weekend after it sat in the workshop for 1.5 months, and it ignited and powered my Darkstar Ultimate OK, but the actual altitude was off quite a bit (40%) from the OpenRocket simulation. Previously flight on the M1500G was within 10% of predicted.

Just curious.

I have an N2100 fully built in my garage. Couldn't launch it in April due to winds, so it will wait till November. It's just sitting there, mocking me. Probably I should wrap it in foil and put it in the basement, but so far I haven't.

The only things that can really damage the motor are excess humidity, and of course ignition. Keep it dry and away from heat and flames.

I also have that same problem. I have a few G-I motors built up, since February-March. Was not able to fire them for one reason or another and launch season is over here until the rains come back. I'm thinking December will be the earliest I will be able to fly them. I just have them in a big ziplock bag with a couple desiccant pouches for now.

I have some small reloads swell up after sitting in storage, even in plastic bags...wouldn't fit the hardware....but they made great fire starters when camping.
I think you should check for oxidation in the central bore....sand it a bit....I got some to light easier that way.

One thing to do is loosen the threaded ends to relieve the compression on the o rings. (And don't forget to re-tighten them when the day comes!) This way the O rings don't get compressed, thus causing a potential gas leak during launch.

Is there any issue with just removing the front and rear closures completely on the CTI 75mm and 98mm? Do the O-rings or propellant need any special storage considerations? I don't like the idea of a large motor possibly being able to produce thrust in a residence in the event of a fire.

ProjectG said:

Is there any issue with just removing the front and rear closures completely on the CTI 75mm and 98mm? Do the O-rings or propellant need any special storage considerations? I don't like the idea of a large motor possibly being able to produce thrust in a residence in the event of a fire.

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If your house is on fire enough to ignite an APCP motor then the motor probably isn't going to make much difference.

I'm more concerned about storing FFFF powder than APCP motors since the powder is extremely easy to ignite.

blue tape over the nozzle is all I do. I'm currently guilty of storing a Loki 76 skid, a EX 76 red and a bunch of EX 54's. Finally flew the AMW K1000 skid that had been sitting around my house at Red Glare ( I built it 2 years earlier). I think my all-time winner was a CTI M1770 which got a solid 3 year wait to fly. I just stuff them in a motor holder and let 'em rip.......

I never release pressure on closures, figure if it's good enough for single use that get stored for years [decades]...good enough for me.
Last Airfest flew and M classic stored for 3 yrs [2015 built] have another M going on 4.

For me a bigger issue CAN be too much grease on liners that sit months/years & saturate [paper/phenolic not black type] usually smaller white paper liners that have glassine removed or have been sanded to fit. [38 and 29mm]

Those can get liners so stuck, they seem glued in.