Shelf life of RMS reloads

Shelf life of RMS reloads

Post by Leslie Hou » Sun, 07 May 2006 04:52:00



Back in 1997 I stocked up on E through G RMS reloads.  I've been using
them on and off ever since, but I wondered if there is an official
expiration date for them.  They have been stored in an air-conditioned
closet all these years, and they still seem to be working fine,
although they have gotten increasingly hard to ignite -- about the only
thing that seems to light them reliably now are Quickburst's Twiggy
igniters.  I did notice that the propellant grains look like they are
sprinkled with talcum powder or maybe powdered sugar, but it doesn't
seem to have hurt their performance once ignited.  Anyone know anything
about the shelf life of these progellant grains?
 
 
 

Shelf life of RMS reloads

Post by Aaro » Sun, 07 May 2006 05:36:33


I have seen the same thing on some of my reloads.  I use sandpaper to
remove the oxidation from the grains and they seem to light faster.
(220 grit on a dowel down the core of the grain for cored grains and
220 grit on a bit of balsa for c-slot grains)

I don't know of that is supported or even smart, but it works for me
and I haven't lost a finger yet.

-Aaron

 
 
 

Shelf life of RMS reloads

Post by Fred Shecte » Sun, 07 May 2006 05:53:45


http://groups.google.com/group/rec.models.rockets/search?group=rec.mo...

--
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Quote:
> Back in 1997 I stocked up on E through G RMS reloads.  I've been using
> them on and off ever since, but I wondered if there is an official
> expiration date for them.  They have been stored in an air-conditioned
> closet all these years, and they still seem to be working fine,
> although they have gotten increasingly hard to ignite -- about the only
> thing that seems to light them reliably now are Quickburst's Twiggy
> igniters.  I did notice that the propellant grains look like they are
> sprinkled with talcum powder or maybe powdered sugar, but it doesn't
> seem to have hurt their performance once ignited.  Anyone know anything
> about the shelf life of these progellant grains?

 
 
 

Shelf life of RMS reloads

Post by Anthony Cesaron » Sun, 07 May 2006 07:27:32


Solid rocket propellant is made out of pseudo stable, smelly polymers and
other ***that are subject to varying degrees of aging, dependant on a very
large number of factors. The short answer I guess is that if it blows up,
it's expired.

Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.FoundCollection.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto


Quote:
> Back in 1997 I stocked up on E through G RMS reloads.  I've been using
> them on and off ever since, but I wondered if there is an official
> expiration date for them.  They have been stored in an air-conditioned
> closet all these years, and they still seem to be working fine,
> although they have gotten increasingly hard to ignite -- about the only
> thing that seems to light them reliably now are Quickburst's Twiggy
> igniters.  I did notice that the propellant grains look like they are
> sprinkled with talcum powder or maybe powdered sugar, but it doesn't
> seem to have hurt their performance once ignited.  Anyone know anything
> about the shelf life of these progellant grains?

 
 
 

Shelf life of RMS reloads

Post by Bob Kapl » Sun, 07 May 2006 22:01:03



Quote:
> Back in 1997 I stocked up on E through G RMS reloads.  I've been using
> them on and off ever since, but I wondered if there is an official
> expiration date for them.  They have been stored in an air-conditioned
> closet all these years, and they still seem to be working fine,
> although they have gotten increasingly hard to ignite -- about the only
> thing that seems to light them reliably now are Quickburst's Twiggy
> igniters.  I did notice that the propellant grains look like they are
> sprinkled with talcum powder or maybe powdered sugar, but it doesn't
> seem to have hurt their performance once ignited.  Anyone know anything
> about the shelf life of these progellant grains?

Last year I flew a 13 year old I284 that had been burried in my stash. Those
who remember the original reloads, this one had the two clear plastic delay
spacer rings! No problems. I've also flown the D-G LMR reloads that were at
least as old as the ones you have successfully.

If the bags are sealed, the propellant should hold up pretty well.
Particularly WL tends to absorb moisture and swell once the bag is opened.
If the grain won't fit in the liner tube, toss it. Otherwise, do as was
already mentioned: rough it up a bit with some sandpaper to de-crud the
surface.

Older grains can be difficult to ignite. The simple solution for the multi
grain reloads is to swap the TOP grain (the one next to the delay where the
ignitor goes) with a fresh one from a motor that uses the same type
propellant. That's what I did with my 13 year old I284, and it was instant
on at ignition.

--
  Bob Kaplow   NAR # 18L   >>> To reply, there's no internet on Mars (yet)! <<<
Kaplow Klips & Baffle:      http://nira-rocketry.org/Document/MayJun00.pdf
    www.encompasserve.org/~kaplow_r/    www.nira-rocketry.org    www.nar.org

Senator, when you took your oath of office, you placed your hand on the
Bible and swore to uphold the Constitution. You did not place your hand on
the Constitution and swear to uphold the Bible. -- Jamin Raskin

 
 
 

Shelf life of RMS reloads

Post by Rick Dunseit » Mon, 08 May 2006 22:37:29


Quote:

> Back in 1997 I stocked up on E through G RMS reloads.  I've been
> using them on and off ever since, but I wondered if there is an
> official expiration date for them.  ... Anyone know anything
> about the shelf life of these progellant grains?

In the last two months I've flown two K550's that I believe dated
back to 1994.  They both worked just fine.

...Rick

 
 
 

Shelf life of RMS reloads

Post by Kevin Trojanowsk » Tue, 09 May 2006 11:44:56


Quote:

> Solid rocket propellant is made out of pseudo stable, smelly polymers and
> other ***that are subject to varying degrees of aging, dependant on a very
> large number of factors. The short answer I guess is that if it blows up,
> it's expired.

Yes, but the $20,000 question is whether catocene and ferrocene make
that timeframe longer or shorter.....