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Re: 1lb Black Powder Rocket Formula needed

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  • KJohnsonFargo
    Jared, Here s what I was using at Tom s this spring: 1. Make large quantities of pine airfloat. Cut 1/2 to 3/4 square pieces of pine just short enough to fit
    Message 1 of 5 , Aug 20, 2012
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      Jared,

      Here's what I was using at Tom's this spring:

      1. Make large quantities of pine airfloat. Cut 1/2" to 3/4" square pieces of pine just short enough to fit in a 1 gallon tin paint can (no interior coating). Fill said paint can with cut pine. Punch 1/4" hole in the center of the lid and affix lid firmly. Place in the center of a hot fire and cook until gasses quit coming out. Cool overnight. Grind up charcoal remains in a hand-cranked meat grinder (check garage sales) and discard any uncooked wood or other stuff that won't grind. Ball mill the ground up charcoal for 3 hours and discard any chunks left after this. You now have nice hot airfloat charcoal.

      2. Mix 60% potassium nitrate with 25% airfloat and 10% sulfur. I know this isn't 100%, the last 5% is coming later. Just use this as a ratio. Ball mill this for 1 hour. The remaining 5% is 80 mesh charcoal. When done ball milling the BP, screen in the 80 mesh charcoal. I usually screen it through 3 or 4 times.

      3. Repeat step 2 but this batch will be 75% potassium nitrate, 10% airfloat and 10% sulfur ball milled for an hour and then screen in the remaining 5% of 80 mesh charcoal several times.

      4. "Rice" each batch of BP by spritzing with water until wet enough to just clump up and then press/scrape it through a roughly 30 mesh screen (I made a screen for ricing BP with just ordinary window screen from Menards, it's about the right size). Let the "riced" BP dry in a tray overnight.

      5. Ram your rocket using the 60-30-10 (step 2) until you're at the top of the spindle. After I've done 1 increment of 60-30-10 with the flat rammer, I then switch over to the 75-15-10 hotter stuff for the last 4 or so increments to give it a little more oomph once the core has burned away. You might be able to get away with switching to the 75-15-10 a little sooner, but eventually you'll start getting CATO's. At first I tried spicing up the 60-30-10 a little for better performance, but found that 65-25-10 yielded nothing but bombs on sticks for me. So now I just stick with what I know works.

      You could definitely skip step 3 and just use 60-30-10 for the whole rocket and it would fly fine, I just like to try to squeeze out as much height as I can on these BP rockets.

      I use 3/8" square dowels that are 36" long for my rockets and they seem to work just fine from no heading all the way up to a lighter 3" ball shell.

      Kevin



      --- In PrairieThunderPyrotechnics@yahoogroups.com, Jared Birk <pyrobirk@...> wrote:
      >
      > Hi Everyone,
      > Robyne and I got our first set of black powder rocket tooling in La Porte
      > last week. We're ready to start pounding, but first have a couple questions
      > 1. Does anyone have a favorite 1lb formula to share?
      > 2. What size sticks should I cut?
      >
      > Thanks!
      > Jared
      >
    • tsklebar@daktel.com
      All, I have the Medlin rocket handout I used when we had the build at my place if anyone wants it. Ts
      Message 2 of 5 , Aug 21, 2012
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        All,

        I have the Medlin rocket handout I used when we had the build at my place if
        anyone wants it.


        Ts
      • Hans
        Awesome to see the list getting used for info exchange. Hans
        Message 3 of 5 , Aug 22, 2012
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          Awesome to see the list getting used for info exchange.

          Hans



          --- In PrairieThunderPyrotechnics@yahoogroups.com, Jared Birk <pyrobirk@...> wrote:
          >
          > Hi Everyone,
          > Robyne and I got our first set of black powder rocket tooling in La Porte
          > last week. We're ready to start pounding, but first have a couple questions
          > 1. Does anyone have a favorite 1lb formula to share?
          > 2. What size sticks should I cut?
          >
          > Thanks!
          > Jared
          >
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