Jump to content


Photo
- - - - -

Nozzle less rockets


  • Please log in to reply
84 replies to this topic

#81 Mumbles

Mumbles

    Grandmaster

  • Admin
  • PipPipPipPipPipPipPipPipPipPip
  • 11,567 posts
  • Gender:Male
  • Location:Above You

Posted 23 May 2020 - 01:23 AM

Justvisiting would be the guy to ask, but I think it should work fine on nozzled motors as well.  You'll want to use a different base formula than 75/15/10 of course for them.


Just so you guys quit asking, here is the link to the old forum. http://www.xsorbit2....forum/index.cgi

The sky is my canvas, and I have 2,113 pounds of powdered paint in the workshop.

#82 justvisiting

justvisiting

    Pyromaniac

  • Full Member
  • PipPipPip
  • 121 posts

Posted 23 May 2020 - 10:44 AM

Does the water of 1-2% apply to all BP motors regardless of construction? Can they all be flown straight away, no wait time?

 

Bourbon, I described my results testing a bunch of 3lb rockets made using water, but I can't find where I posted! Anyway, I used 2 1/2% water for the nozzleless 75-15-10 rockets and 3% for the nozzled 60-30-10 rockets. They were stored for a few weeks. I used waxed tubes. When I pressed motors with damp propellant in unwaxed tubes, I got tube compression. With waxed tubes, the consolidation was perfect. The rockets can be flown right away. It was very interesting to me that after 3 or 4 weeks of storage, less than a gram of water was lost from each motor. Black powder has a tendency to absorb moisture if it is perfectly dry. It seems that deliberately adding the water stabilized the propellant so that it would neither absorb or shed water.

 

One thing I like to do is to 'pre-densify' my rocket propellant by making the dampened propellant into soft 'pucks', which I break down by forcing through a heavy screen. The propellant can be stored for over a month in a tightly sealed container, and used as needed. Once I tried water in my BP rockets, I was hooked. I'll never go back to dry pressing again. 


  • Bourbon likes this

#83 Bourbon

Bourbon

    Playing with fire

  • Full Member
  • PipPip
  • 20 posts
  • Gender:Male
  • Location:Oregon
  • Interests:1# BP Stingers right now.

Posted 23 May 2020 - 10:01 PM

Thanks for the input guys. I'll definitely try this in the near (real near) future. Just for clarity, this is 3% water right before pressing or ramming? Not thee initial wetting just before forming pucks or granulating right? I'll be using nozzle cored 60/30/10. To start anyway.



#84 justvisiting

justvisiting

    Pyromaniac

  • Full Member
  • PipPipPip
  • 121 posts

Posted 24 May 2020 - 12:31 AM

Yes, 3% water added, with no (intentional) drying. I screen the dampened mix a couple of times, and hand mix. Then I let it rest for a little while, covered. I make a puck, and immediately granulate it through (let's say) 10 mesh. If it is too soft and crumbles back to dust, I press the next one a bit harder. If it's too hard, I back off. Then I process the batch. The dampened, crumbled propellant is  a pleasure to use. There's no dust, and each increment has less volume than loosely granulated propellant would have. So, the tube is less likely to pull down when pressing. For me, waxing the tube is important too. I don't worry about wax in the nozzle area, since I apply it very thinly. I don't get blowouts or blowthroughs. Using water and wax gives me reliability in my rockets, and I don't mind a little extra work to achieve it. I would highly recommend dampened propellant for hand-ramming if dry propellant won't work.


  • Bourbon likes this

#85 Bourbon

Bourbon

    Playing with fire

  • Full Member
  • PipPip
  • 20 posts
  • Gender:Male
  • Location:Oregon
  • Interests:1# BP Stingers right now.

Posted 24 May 2020 - 07:59 AM

Yes, 3% water added, with no (intentional) drying. I screen the dampened mix a couple of times, and hand mix. Then I let it rest for a little while, covered. I make a puck, and immediately granulate it through (let's say) 10 mesh. If it is too soft and crumbles back to dust, I press the next one a bit harder. If it's too hard, I back off. Then I process the batch. The dampened, crumbled propellant is  a pleasure to use. There's no dust, and each increment has less volume than loosely granulated propellant would have. So, the tube is less likely to pull down when pressing. For me, waxing the tube is important too. I don't worry about wax in the nozzle area, since I apply it very thinly. I don't get blowouts or blowthroughs. Using water and wax gives me reliability in my rockets, and I don't mind a little extra work to achieve it. I would highly recommend dampened propellant for hand-ramming if dry propellant won't work.

:) Right on. Thanks!






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users