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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.

Candy Reloads of Estes & Quest Motors

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.

Candy fuel slugs for reloading ESTES motors

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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