BP nozzled

[Richtee]

So, apparently my BP is too hot for nozzle. I seen the modded formulas, but I only make a rocket er two for grins. What’s the % of baking soda I can add to slow it down? Or... charcoal I guess. 5% by weight?

 

Smoked an Estes rocket last weekend. It was amusing to me. The grandson..not so much

[Guernica]

Charcoal makes sense so you get the benefit of the additional sparks... maybe try an additional 5-10%. Or try without a nozzle.

[Arthur]

Put an extra 5% of charcoal in the powder, try 10% if you need more reduction in speed. Choose your charcoal to get different tail appearance.

[Richtee]

Thanks gentleman. Here I spend my time making the best BP I can. And the best is NOT the best for some things.

 

And I will try a nozzle less. Never have.

Edited June 13, 2023 by Richtee

[davidh]

Nozzleless rockets are dumb.

 

I'll bet money you introduced a core. It doesn't take much. A quarter inch will go boom.

Barring that, the nozzle diameter is too small. Wire gauge drill bits are your friend.

 

FWIW, end burners, which is what Estes engines are, should be made with the hottest BP you can muster.

[davidh]

BTW, if you're making a cored rocket, which very much isn't like an Estes engine, then you must use 6/3/1 rocket propellent (RP). Smaller cored motors require "hotter" RP, so use airfloat charcoal for 1-2oz. As the motors get larger, make a larger percentage of the 30% charcoal out of a larger mesh cut.

[Arthur]

Lancaster's book gives some rocket fuel mixes for different bores, the smallest ones use fast BP then as the size increases there is a bigger added charcoal proportion going up to 30% added charcoal in big tubes.

[justvisiting]

"Nozzleless rockets are dumb." What a stupid remark.

[davidh]

"Nozzleless rockets are dumb." What a stupid remark.

Opinions vary. :-)

[davidh]

Lancaster's book gives some rocket fuel mixes for different bores, the smallest ones use fast BP then as the size increases there is a bigger added charcoal proportion going up to 30% added charcoal in big tubes.

The small rockets, like the 1oz rocket (1/4"), are fickle. They can work with straight BP, but they can also blow up. I think it's harder to make a good 1oz rocket than a good 3lb rocket. By the time you get to 3lb, just about any slow RP mix will work fine.

[Arthur]

Lancaster's formulations were either "borrowed" from other firework manufacturers or developed from his own work, so I don't doubt his formulae, but they may not be the only ones that work. Sometime it's like cookery lots of formulae/recipes work but some better than others.

[Richtee]

I guess I’ll make a 200 gram batch of +5% charcoal BP. Rather than adulterate the stuff I have now. I have 5 .75” X 3” ID rolled tubes with water putty plugs ready to go. I have been using .25 drilled nozzles. Admittedly I have knicked the powder grain a bit. Will be more diligent there.

 

Think I’ll stick with Estes motors for the grandkids tho. CATO’s/RUD’S tend to upset them