Rocket fusing

[jstorres486]

Hi all i have a quick question.. where is the best place to fuse a 1pound bp nozzleless rocket? Is it good to j hook right inside the nozzle or try to fuse all the way on top(down the tip of spindle). Its a 75-15-10 bp and im only getting about 100 feet height.. i ball mill for 4 hours then add 2 percent mineral oil( maybe to much oil), run tru mesh screen half dozen times and then press to 6000 psi on the comp.. rocket doesnt seem super fast.. thank u!

[Guernica]

You may want to try fusing deep in the core, particularly with blackmatch this works well to propogate the initial flame as intensely as possible, but also I'd try omitting the mineral oil altogether. Also, if you're ballmilling why are you also screen mixing? Dampen your fuel a bit by misting water on it (try 1.5-2% water by weight) immediately before you press your rockets- no mineral oil- and maybe see what that gets you. Also, milling for more than 4 hours will probably make a difference, particularly if you don't have an optimized mill setup...

(edit: when I say dampen your fuel with water immediately before pressing, it could also be an hour before if you let it sit/temper in a closed container- this can be a nice way to homogenize the moisture a bit. My point was to have to fuel slightly damp *while* pressing, this dramatically aids compaction. This is different from granulating your fuel with water after milling, which is a different step I didn't get into in my original response, but if you read all the past rocket threads here, you'll learn about that step too.)

(additional edit: I'm guessing maybe you're screening your mix after milling to incorporate the oil thoroughly- and this makes sense, but still, try it without the oil. Depending on how evenly you spritz water on the fuel, you may still want to run it through a screen to homogenize the moisture, although I find that to be unnecessary if I spray it fairly evenly & let it sit to temper in a closed container)

Edited May 21, 2024 by Guernica
Additional clarity

[Arthur]

Take a mill full of ingredients as before. Mill for 4hrs and take a sample (one rocket's worth) mill the jar for another 3 hours, take a sample. Then mill for another three hours and keep this.

This way you can get a clue how much milling is best, you want to use the mill time just short of a cato. Maybe after 4, 7 and 10 hours milling you test say 8 and 9 hours mill time and get flight times from every test to determine optimum mill time.

[jstorres486]

Thank u guys I’ll try this out.. I do screen only to incorporate the mineral oil.. I’ll try water instead.. I’m doing a batch now at 10 it will be 4 hours.. I’m going to take out 100 grams and keep killing for additional 4 hours see how that works.. again thank you

[Arthur]

Remember that rocket fuel is the fastest BP that does not explode (CATO) usually commercial rockets are well off the explode formulation for retail and trading responsibilities. 

 

[Kalifireworks]

On 5/22/2024 at 11:17 AM, Arthur said:

Remember that rocket fuel is the fastest BP that does not explode (CATO) usually commercial rockets are well off the explode formulation for retail and trading responsibilities. 

 

I tend to disagree on this. Blackpowder rockets work by using a slow burning fuel and a nozzle. Thats what Literature says.

 

Thats how they get reliable.

[Arthur]

Some old texts suggest making rocket fuel by taking full power fine BP and mixing it with BP ingredients of some specified particle size. So this is fast BP Mixed with unincorporated ingredients to slow it down to prevent CATO. Big rockets need slower powder.