moondogman Posted February 27, 2011 Posted February 27, 2011 (edited) Has anyone ever tried pyrodex pellets for rocket fuel? I have a box of pellets that are several years old and thought I might try them in a tube with a nozzle. Could they be crushed and rammed??? I might need to dip them in somthing to slow them down a bit. Any thoughts. Thanks Steve Edited February 27, 2011 by moondogman
dagabu Posted February 27, 2011 Posted February 27, 2011 I am not a fan of modifying powders for Pyro use. I suggest that you dont use them for rockets but trade someone for BP.
cplmac Posted February 27, 2011 Posted February 27, 2011 Yeah pyrodex is already very slow stuff. It's also coated with graphite which is why it's so shiny, and I'm fairly certain it contains nitrocellulose. I'm sure it would work in a rocket with a tight enough nozzle, but I have no idea how well you could consolidate a fuel grain with it.
dagabu Posted February 27, 2011 Posted February 27, 2011 cplmac!! Good to see you back here! Do you have any new videos for us?
cplmac Posted February 27, 2011 Posted February 27, 2011 Just put a new one up yesterday, I'm using youtube instead of a whole other website now. Good to be back.
moondogman Posted March 7, 2011 Author Posted March 7, 2011 Well I tried it yesterday. I made 4 rockets with pyrodex 2 rammed 2 loose pellets the rammed ones flew a bit. I hit a little peice of one with a hammer to test if i thought i should ram it or not. The loose pellets blew up one like a little mortar. I used some cheap 5/8 tubes and a dowel rammer I also made 4 sugar rockets with this setup and man did they go. Much better than I thought Now i need to make more. Steve
Juiceh Posted March 7, 2011 Posted March 7, 2011 How well did the rammed pyrodex rockets fly? What kind of tooling did you use? Also, what made you think loading a rocket with loose pellets wouldn't blow up? I have about half of a 1Lb jar of that stuff just sitting around. I might try ramming some into rockets to get rid of it.
moondogman Posted March 7, 2011 Author Posted March 7, 2011 How well did the rammed pyrodex rockets fly? What kind of tooling did you use? Also, what made you think loading a rocket with loose pellets wouldn't blow up? I have about half of a 1Lb jar of that stuff just sitting around. I might try ramming some into rockets to get rid of it. Not nearly as good as the sugar rockets. I drilled a bigger hole in the nozzle for the loose pellets. just thought they might fly. The tooling was just a peice of dowel glued into a 2x4 about a 1/2 inch long and and a dowel with an angle cut for the rammer then i drilled 1/8th holes about 2/3 of the way into the fuel. I used bentonite for the nozzle and bulkhead. Very basic !! Ive got some 20+ yr old black powder im gonna try next. Steve
moondogman Posted March 8, 2011 Author Posted March 8, 2011 Well I made 6 more last night all with 1/8 drilled cores. The 3 sugar rockets flew wonderfully higher than I could see. The 1 pyrodex got about 10 foot up and exploded I packed this one much harder than yesterday (found my dead blow hammer) Both comercial bp (20yr old goex fff) catoed big time. Im guessing I need larger cores. Looks like if i want to do this right Im gonna need to buy some tooling. Steve
Juiceh Posted March 8, 2011 Posted March 8, 2011 Both comercial bp (20yr old goex fff) catoed big time. Im guessing I need larger cores.You actually probably need the exact opposite. A Larger nozzle and shorter core will be able to handle hotter fuel.
dagabu Posted March 8, 2011 Posted March 8, 2011 Go nozzleless if there is to much pressure. They are very hard to CATO.
Mumbles Posted March 9, 2011 Posted March 9, 2011 Using full strength meal in a cored rocket will cato almost everytime. It's really better suited to nozzleless rockets and end burners.
Nessalco Posted March 9, 2011 Posted March 9, 2011 I use pyrodex pellets to light my rocket motors. They'll get a 30 pound slug of APCP burning pretty well - though cupric thermite works better Kevin O
WSM Posted March 10, 2011 Posted March 10, 2011 Pyrodex is prone to absorb moisture from the atmosphere. I have a friend who shoots black powder firearms and he recommends placing a 1/2" layer of Pyrodex on a cookie sheet and drying it in an oven turned low (try 200oF or 90oC) for an hour. Then store it in a container with a dry dessicant pack. An alternative to drying it in an oven is to place the tray on the dashboard of a car, in the sun, with the windows only opened a very little, for ventilation. This sounds crazy, but it works. I believe nearly any pyrotechnic composition with a reasonable burn rate can make a rocket fly, but be ready to adjust the tooling to match the propellant. Lacking machining capability, adjust the propellant to match your tools. WSM
MadMax Posted March 11, 2011 Posted March 11, 2011 WSM, I'm not sure that I would recommend putting pyrodex in an oven. It's bp-based and as such has a low ignition temp. It's not as low as bp but still low enough that if the oven sparked or some granules fell onto the heating element you might end up having to explain to your wife/girlfriend why glass from the oven door is all over the kitchen and the walls are blackened. Lol. But seriously I wouldn't oven cook it. I have another post on drying BP using a hair drier aimed at it. If you are really serious about it and want the powder to be as dry as possible you could use a dessication bag. Here's how to set one up. Take a large airtight bag. In that bag put 2 bowls - one containing your pyrodex and the other containing a sufficient amount of ammonium nitrate. With this bag sealed ammonium nitrate is so hygroscopic that it will suck all the water out of the surrounding air including whatever water was in the pyrodex. If let to sit undisturbed for several days it should completely dry the powder. Once done the ammonium nitrate will be all soggy. Drying that stuff out isn't too easy but can be done. Pyrodex is prone to absorb moisture from the atmosphere. I have a friend who shoots black powder firearms and he recommends placing a 1/2" layer of Pyrodex on a cookie sheet and drying it in an oven turned low (try 200oF or 90oC) for an hour. Then store it in a container with a dry dessicant pack. An alternative to drying it in an oven is to place the tray on the dashboard of a car, in the sun, with the windows only opened a very little, for ventilation. This sounds crazy, but it works. I believe nearly any pyrotechnic composition with a reasonable burn rate can make a rocket fly, but be ready to adjust the tooling to match the propellant. Lacking machining capability, adjust the propellant to match your tools. WSM
Ralph Posted March 12, 2011 Posted March 12, 2011 pyrodex usualy contains perc and benzoate among other things I wouldnt be ramming it
WSM Posted March 12, 2011 Posted March 12, 2011 WSM, I'm not sure that I would recommend putting pyrodex in an oven. It's bp-based and as such has a low ignition temp. It's not as low as bp but still low enough that if the oven sparked or some granules fell onto the heating element you might end up having to explain to your wife/girlfriend why glass from the oven door is all over the kitchen and the walls are blackened. Lol. But seriously I wouldn't oven cook it. I have another post on drying BP using a hair drier aimed at it. Hi MadMax, I should have mentioned, "I like sleeping indoors" so I never did this myself. My friend is single and doesn't have to answer to another person if the oven gets ugly or smelly. I do have a small electric lab oven for "industrial" heating uses that I could use outdoors if I needed to do something like this. If properly controlled, it can be done perfectly safely; just be certain to stay well below the activation energy of the mixture . The hair drier method would cause me more concern due to lower control of the total heating and the possibility of generating "hot spots" where the mix could get hot enough to take off (plus the close proximity of the operator). Unfortunate results may happen. It's good to anticipate and try to minimize any unsafe situation before we start an operation. Using dessicants can work (slowly) and if combined with a vacuum, work even better. If you live in an area that gets plenty of sun, a hot box can be made of a metal cabinet (any size), painted black and with a computer fan (baffled) running for airflow (don't forget to have two vents; one for air intake and the other for air output; and DO cover the vents with filters to prevent things getting in or out!). Run the hot box in full sun and at the end of a long extension cord, away from anything flammable. Simply setting the powder on a layer of paper on a metal screen, tilted up slightly for airflow, with a slow fan blowing across it from a safe distance will dry the powder much, much faster than still, ambient air (although, I'm not sure this is the best approach with hygroscopic mixtures; it works great for BP mixes). I'm saying there are several ways to solve the problem, but work safely. Do the homework neccessary to understand the nature of the materials you're dealing with and work within safe limits, taking due cautions, and all should be well. Do everything in your power to prevent injury to persons and property (including yourself). WSM
WSM Posted March 12, 2011 Posted March 12, 2011 pyrodex usualy contains perc and benzoate among other things I wouldnt be ramming it Hi Ralph, Thank you; good point! When in doubt PRESS, don't ram mixtures. If you don't have a way to press compositions, either find or make one, but don't compromise your safety by pounding on sensitive mixtures. It's just not worth the risk. The most dangerous thing in a pyrotechnists workshop is impatience (lose it!). Also, It's sodium benzoate which is why the hygroscopic problems. WSM
moondogman Posted March 12, 2011 Author Posted March 12, 2011 Hi Ralph, Thank you; good point! When in doubt PRESS, don't ram mixtures. If you don't have a way to press compositions, either find or make one, but don't compromise your safety by pounding on sensitive mixtures. It's just not worth the risk. The most dangerous thing in a pyrotechnists workshop is impatience (lose it!). Also, It's sodium benzoate which is why the hygroscopic problems. WSM I gave up on them as a fuel but i bet they will make decent short lived stars. Steve
WSM Posted March 12, 2011 Posted March 12, 2011 I gave up on them as a fuel but i bet they will make decent short lived stars. Steve Hi Steve, With an appropriate binder and metal additives plus decent priming, I don't doubt it. Nice way to turn a sow's ear into a silk purse. WSM
pyrojig Posted March 12, 2011 Posted March 12, 2011 I gave up on them as a fuel but i bet they will make decent short lived stars. Steve You can make decent stars by adding magnalum as a fuel at around 5-10% . They are kind of orange'ish in color, and burn fairly long. I did the same thing with a 1lb can of pyrodex a while back. The rockets made suck , but will fly. I made nozzless bottle rockets out of them. The burn characteristics of pyrodex is a strange animal, hence the cato's with the nozzled ones. The pressure build up is like a spike in pressure v.s. bp where it is very consistent.
Recommended Posts