Reloading ESTES Motors with "Candy"
Content Copright 2001, 2002, 2003 by Private
Data, LLC
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My son generates a lot of used ESTES and QUEST rocket motor casings. To
me they begged to be reloaded - especially as the source product is relatively
expensive. But, for me, reloading or making anything, past the novelty of
it, it must be worth the effort. This precludes pulverone reloads as my current
break even is about the 1lb rocket level. Candy is easily workable so I sought
to come up with a quick yet effective technique for reloading these casings
with Candy.
After some discussions with Jimmy Yawn
he cut through my musings and suggested I read up on his experiments with
free-standing (uninhibited) grains and attempt to adapt his work in this
context.
I did so and with decent results. Note that these motors do not have a motor
ejection charge. I did not want to tackle that for these quick and dirty reloads.
I don't need to either as 2 of my son's 3 models are UFOS (a Snitch
and an Art Applewhite) and neither
need ejection charges.
WARNING - This is intended
to be a guide for experienced EX experimenters - you assume all risk for your
activities.
I made up a batch of Candy in the Waring Kitchen Kettle (dedicated to this)
in the usual proportions of 65% KNO3 / 35% Sorbitol with +2% Fe2O3 (Red Iron
Oxide) for a burn rate catalyst. The KNO3 was milled K-Power fertilizer and
the Sorbitol from The Sugarless Shop. After letting this cool enough to handle
I rolled it out into logs of manageable length and let them harden overnight.
In this picture I also rolled them in some hot willow prime powder - (with
little efficacy as I'll note later).
The red gob in the PVC pipe section is the remainder of this batch of Candy.
I heard my wife pulling up and that meant the kids would soon be upon me
so I packed the gob on the pipe and put the tray away up high. Since that
gob is contaminated with BP I will not attempt to re-process it into logs
- fearing ignition during re-heating (an unnecessary risk) - and will just
burn it for fun as a smoke charge in the backyard.
The logs are rolled to a size that is a loose fit inside the case. The logs
are then cut to approximately 4.5cm long. When cured overnight they are cleanly
snapped to length with pruning shears - no messy sawing required. The cases
are prepp'd by cleaning out the nozzle with the appropriate size drill bit
(by hand - no drill required) to remove slag and deposits. The inside of
the case is given a quick reaming with a dowel and tapped out. The slugs
are loaded into a case and followed with a 1/2" piece of wooden dowel slathered
with carpenters glue. These are left to dry overnight and then they are ready
to use.
I have been igniting these with Visco fuse and found ignition of the initial
batch inconsistent. A preload of a few grains of 4F and the motors were off
and flying. I now prime the ends of the grains with a primer paste for more
positive ignition. This primer paste is composed of milled pulverone
wet with 5% NC lacquer. (Loosely, pulverone means "amateur homemade BP";
it is actually milled "green mix" and would have to be pressed and corned
to truly be BP)
I have not measured these on a test stand but estimate these to be in the
high B / low C range. As an uninhibited grain the burn is progressive.
I also tried cored motor reloads - but with less than satisfactory results.
While the motors fired, they were weaker than the uninhibited grain motors.
They were messier as well - particularly as packing the cores was difficult
to do without contaminating the end of the case with candy. In one test I
did successfully plug the end with Candy itself - but they landed, still
burning, in the woods. (That test was conducted safely, specifically immediately
after a heavy rain). Note that Jimmie had also tried cored uninhibited slugs
with good success. I have not yet tried that. My cores were 1/8" using brass
rod.
Resources:
Jimmy Yawn
Richard Nakka
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