Shelf life of assembled Loki motors?

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

muddymooose

Hoopy Frood
Joined
Jul 5, 2017
Messages
443
Reaction score
105
Location
Palmyra, MI, USA
On Friday I assembled a 38mm Loki H125 and a 38mm Loki I210 for Saturday's launch, which was then cancelled for rain.

I now plan to use them at the November 11 launch unless that gets cancelled for weather.

Will these assembled motors be fine until November 11? How about until next April in case November is cancelled? Will keeping them in a zip-lock bag indoors be sufficient to keep them fresh?
 
I have assembled Loki and Aerotech motors one year (end of the flying season and then got high winds and shut the range down) and used them the next spring with no problems. I’ve also left the black powder ejection charge out out and then forgotten to add it and watched the rocket dive to its death. Leave yourself a note telling yourself what the load is, what’s been done and what remains to be done. Don’t be dumb like I was. It’s a hollow feeling to see the rocket come down and then see the BP container still in the bag.


Steve Shannon
 
I always remove and repack BP if it is going to sit for a while but a month is nothing. Steve's idea is a good one if you do modify the load. I glued up an L1400 a few weeks back and ended up not launching, so I just disassembled the load and wrapped the liner with the grains in saran wrap. If it is sealed it should be as good as packed from Loki, I won't get a chance to use this reload until the spring and I have no concern.
 
If you want to be extra cautious, put it in a zip-lock bag and squeeze the air out.
 
I completely assembled a Loki 76 / 6000 M 2550 LB a few weeks before Airfest 2015...
At Airfest 2016 the flight was scrubbed ...
The following spring someone wanted to borrow my 76 / 6000 hardware to fly an M 1650 CT...
I took his bag of forward parts,, smoke grain,, o rings,, and slid my grains and liner out of the case...
He slid his grains and liner in and flew it -- no issues at all...
He cleaned the case,, we assembled the forward with the parts from his bag O foward parts...
And I flew the M 2550 LB at Airfest that year- 2016,, no issues at all...

Composite propellent can be hygroscopic,,
some recipes more than others,, but just assume it is,, at least a bit...
Wrap it,, bag it,, seal it,, anyway you can if you have any concern...

Also,, any motors,, any concern,, take it apart and regrease all of the O rings a bit..

Teddy
 
Composite propellent can be hygroscopic,,
some recipes more than others,, but just assume it is,, at least a bit...
Wrap it,, bag it,, seal it,, anyway you can if you have any concern...

Also,, any motors,, any concern,, take it apart and regrease all of the O rings a bit..

Yes, yes, yes to what Teddy said.

Pssst..... I taught him that. ;-)
 
Hi All,

I purchased an inexpensive food vacuum bagging machine from Bed Bath and Beyond. I purchased it to seal up bottles of sunscreen after one burst open in my airline checked in baggage. The vacuum bagger works great on built motors. I bagged a CTI 54 mm Motor last year in November after weather canceled our last launch of the year. The motor worked fine when it finally flew in June of 2017. You don’t have to worry about humidity allowing moisture into the motor if it’s vacuum sealed.

All the best,
Bob
 
Back
Top