Question on engine shelf-life?

Question on engine shelf-life?

Post by Derek Fo » Sat, 04 Mar 1995 12:52:02



I have about 100 Estes engines (size A, B and C) stored in a dry ammo
box.  They have been there for over 6 years.  I called Estes and someone
stated that engines have no shelf lift, therefore they all should be
good.

The engines were stored laying flat (horizontally).  Since some solids
behave as liquids over time and sag does any one know if these engines
are still any good, or still safe?


 
 
 

Question on engine shelf-life?

Post by JJirvi » Sun, 05 Mar 1995 08:17:25


Being a lose powder or grain, the ejection should degrade.  The propellant
being a solid grain will not very much.  In the case of black powder the
storage conditions matter with cool and dry being preferable.  Composites
of course can withstand much longer periods and slightly worse conditions
including (gag) sal***er.

Jerry

 
 
 

Question on engine shelf-life?

Post by C. D. Tavar » Sun, 05 Mar 1995 09:28:35


Quote:

> I have about 100 Estes engines (size A, B and C) stored in a dry ammo
> box.  They have been there for over 6 years.  I called Estes and someone
> stated that engines have no shelf lift, therefore they all should be
> good.
> The engines were stored laying flat (horizontally).  Since some solids
> behave as liquids over time and sag does any one know if these engines
> are still any good, or still safe?

Small black powder engines essentially have an indefinite shelf life.
D's and up would probably also, if you could assure yourself that you
had kept the environment constant over all that time.
--


                              write today for my special Investors' Packet...

 
 
 

Question on engine shelf-life?

Post by William G » Sun, 05 Mar 1995 03:55:42


Quote:

>I have about 100 Estes engines (size A, B and C) stored in a dry ammo
>box.  They have been there for over 6 years.  I called Estes and someone
>stated that engines have no shelf lift, therefore they all should be
>good.

>The engines were stored laying flat (horizontally).  Since some solids
>behave as liquids over time and sag does any one know if these engines
>are still any good, or still safe?



I had some Centuri Engines that were buried in my Launch kit for almost
20 years, when I drifted away to college and work. When I resumed
Rocketry, I found these engines and tried to use them.

The Thrust appreared to operate normally. The rockets flew in prime
form. However, the ejection charge failed to have adequate force on each
of the three flights that I attempted. The result was a nominal repair
task, in each case. One of the models I flew with these was a re-creation
of the old Centuri model "The Point." The model's conic airframe serves
as it's own parachute, normally with the ejected engine keeping the attitude
correct for recovery. The only engine recommended for it was the B4-2.
It keeps it from arc-ing over at apogee.

On the topic of engines, 20 years is a long time to be sitting and
gathering dust. Yet the thrust operation was not a problem. I think
that if the engines get to be over 10 years old, I will start to become
cautious about whether or not the ejection charge is still "up to snuff."

--
BG
(no .sig yet)

 
 
 

Question on engine shelf-life?

Post by Ralph Straus » Fri, 03 Mar 1995 16:58:15


On (03 Mar 95) Derek Fort wrote to All...


 DF> Path: armon!psgrain!reuter.cse.ogi.edu!uwm.edu!vixen.cso.uiuc.edu!howland.r
 DF> ston.ans.net!ix.netcom.com!netnews
 DF> Newsgroups: rec.models.rockets
 DF> Organization: Netcom

 DF> The engines were stored laying flat (horizontally).  Since some solids
 DF> behave as liquids over time and sag does any one know if these engines
 DF> are still any good, or still safe?

    It sounds like it might be a good idea to take a 10% random sample and
    do some static testing on them. if the static test work i would say you
    are in luck. if not its just as well you didn't use them in a bird.

... Can taglines have sequels?  Hmmm.....

 
 
 

Question on engine shelf-life?

Post by kaplo.. » Fri, 10 Mar 1995 03:10:39


Quote:

> I have about 100 Estes engines (size A, B and C) stored in a dry ammo
> box.  They have been there for over 6 years.  I called Estes and someone
> stated that engines have no shelf lift, therefore they all should be
> good.

> The engines were stored laying flat (horizontally).  Since some solids
> behave as liquids over time and sag does any one know if these engines
> are still any good, or still safe?

Shouldn't be a problem unless they've been heated in storage. I routinely
fly motors at least that old, and have some that are 25 years old. All work
fine.


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Question on engine shelf-life?

Post by Doug Holvers » Sat, 11 Mar 1995 16:58:08


DF> I have about 100 Estes engines (size A, B and C) stored in a dry ammo
DF> box.  They have been there for over 6 years.  I called Estes and someone
DF> stated that engines have no shelf lift, therefore they all should be

I have launched engines that are about 25 years old and they work as good as
new.

-DGH-

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