1 lb rocket nozzleless....

[fredopyrox]

Hello I have multiple questions about your method for 1lb rocket nozzleless :
1) are you ball milling your fuel or screen mixing ?
2) are use minéral oil or other flegmatizer ?
3) are you fusing at bottom like whistle rocket method ? Or little deeply with j hook visco fuse ?
4) what are you use for your first increment ? 2 teaspoons ? 2,5 teaspoons ? 3 teaspoons ?

I ask this is because I tested a nozzleless black powder rocket with this hot fuel ( 75-10-15) the coal is juniper’s ken, I granulated without dextrin with kitchen colander, my first increments are 2 teaspoons , after 1 tspoon, and I press with hydraulics press 6 tons ;I fused with visco with j hooked like I fuse my nozzled rocket, but I have big Cato !!!Thanks for read this long post ...

[Lloyd]

Fredo,
I make very few rockets, but have made tens of thousands of high-performance gerbs. Most of the principles are the same.

Ordinarily, because different fuels granulate so differently, we would not begin by measuring the amount of each increment, but rather measuring how much of the tube is filled by each. I prefer to press 'regular' gerbs at no more than one tube inside-diameter of height per increment. For our 40' and 50' high-altitude gerbs, we'd press to 1/2 tube i.d. of height per increment. Once we had determined the correct fill height per increment, then we would measure future loads of that same powder by volume.

Your CATO sounds to me as if it were caused by a cracked fuel grain, or separation from the tube walls. Oil or wax can serve not only to phlegmetize the fuel some, but also will aid in flow and binding to the tube wall.

Lloyd

[davidg]

Your first increment seems too much. I make 1lb rockets with 4.5gram increments and a tube support for pressing. I use mineral oil as a phlegmatizer at 3% of black powder.

[Pyro-Gear]

Freddy, that juniper charcoal is very hot so you may want to cut down to 68/22/10 for your BP.
The BP is not granulated or made to pulverone, rather it is used as it comes from the ball mill. The mineral oil keeps the dust down and makes the BP soft and easily compacted. Hard grained BPs will often CATO because it is so difficult to eliminate the tiny faults in the compressed grain, the mineral oil (baby oil) is added at the last 15 minutes of milling time.

[fredopyrox]

Hi ken , yes you are right , I tested burn rate and this charcoal is very hot !!! But the baby oil don’t stick in the walls jar? Or maybe i can mix baby oil by hand?

[Pyro-Gear]

You won’t have a problem with the oil sticking to the jar just make sure it is 2-3% max Freddy

[fredopyrox]

Thank you very much !!!

[Pyro-Gear]

Keep us posted Freddy.

[Boophoenix]

I’m not a rocket fella so don’t hunt me down if I’m incorrect.

I believe TR uses 1 percent water misted into his rocket propellant. Ned picked up the same practice. It’s just enough to settle the dust making it more pleasurable to handle. I don’t believe they have any issues pressing and using right away either. TR doesn’t work that way but Ned does build and shoot onsite often.

I figured it might be worth saying for cost and simplicity sake.

[Pyro-Gear]

Got a feeling Brad that TR uses a skinny spindle and a clay nozzle, I know he uses nitrate at 58% so that would make sense could be wrong though.

[Boophoenix]

Uh oh, think I use to know the answer to that statement. Very interesting fellow full of willingness to share. I met him a few years ago and got to spend a little time with him and one other before the crowd grew to annoying level. Not a big public internet communicator though. He was finally convinced to join a Pyro forum and pops up from time to time with the handle EndDisk.

He is pretty mild with his rockets as he states they are orientation devices. He’s not looking to launch his wares to the moon just a decent display height.

Very creative and maticulous builder. Most certainly a master of his craft.

[fredopyrox]

Hello , I just ball milled a 300g batch of bp with 3% baby oil, I must let dry or it is ready for press? Thanks...

[Lloyd]

They're ready to press. Even if there's an evaporative solvent in the oil (unlikely), its amount will be so small as to not interfere.

Lloyd

[Pyro-Gear]

Agreed press away but don’t go to crazy on the pressure, stop and think that rocket could be hand rammed and still perform perfectly trust me.

[fredopyrox]

Hello , here news about my batch :65/25/10+ 3% baby oil Johnson, just ball milled 35mn , I pressed this to nozzled rocked , I don’t see chuffing, but it decreasing power versus granulated without dextrin? IT need little pressure with baby oil ? What and Where do you buy your oil? Thanks again you are nice pyro guys ! Don’t change please!!