Pyrodex vs Black Powder

[cwbullet]

This is a tangent off of the Ejection Canister discussion. What the the strengths and weakness of each?


Clearly to me Pyrodex is less energetic but is cleaner burning.

[o1d_dude]

Black powder in FFFFg is an extremely fine grained compound and burns much quicker.

Goex 4Fg seems to be the BP of choice among the local rocketeers.

[cwbullet]

I use either FFFg or FFFFg BP, Usually the latter.

[glenbo]

I ground tested pyrodex this last weekend and the results were inconsistant. Tested 1.5 and 2 grams in upper section of my talon 4. 2 grams seemed like overkill the first time the second time it barely moved the nosecone. The powder burned completly and was tightly packed and sealed. Just got my hands on 4f goex bp and will retest using the bp. This is what I want to use for ldrs.

[cwbullet]

I ground tested pyrodex this last weekend and the results were inconsistant. Tested 1.5 and 2 grams in upper section of my talon 4. 2 grams seemed like overkill the first time the second time it barely moved the nosecone. The powder burned completly and was tightly packed and sealed. Just got my hands on 4f goex bp and will retest using the bp. This is what I want to use for ldrs.

I can tell this is the same results I have gotten. I feel it is too unreliable unless you are very good at packing it tight.

[glenbo]

Not worth taking the chance von your rocket investments

[cwbullet]

agreed. I will stick to BP even if I have to continue to buy 5 lbs at a time.

[karlbaum]

I have used a lot of Pyrodex. I don't believe it is less energetic nor is it cleaner burning than bp. But, pyrodex must be contained or it will be less energetic. It was formulated to use in a rifle. So I have had much success with pyrodex but I am switching to bp because it is better in my opinion and my dealer sells it.

[RadManCF]

I'm trying to use FFg pyrodex at the moment, the only ground tests I've performed thus far have been to determine how easily it can be ignited, I've only packed my canister and ignited the powder, I haven't yet installed the canister in a rocket. I'm using a rigid canister, made from a black iron pipe nipple, about 9/16 in diameter, 4 in long, with a cap brazed onto the end. About 1/4 - 3/8 of the canister is filled with powder, the remainder is filled with dog barf. The contents are tamped, and more dog barf is added. The end of the canister is then taped. I used Q2G2s for ignition, the first test took a couple seconds to ignite, but the second ignited immediatly. The second charge was more tightly packed. I didn't do more tests, because I live in the suburbs, and while I conducted the tests in my garage (in a sand filled bin, with the business end pointed up), they were stll loud enough that the neighbors might have noticed. I hope to do more tests soon though.

[cwbullet]

I have used a lot of Pyrodex. I don't believe it is less energetic nor is it cleaner burning than bp. But, pyrodex must be contained or it will be less energetic. It was formulated to use in a rifle. So I have had much success with pyrodex but I am switching to bp because it is better in my opinion and my dealer sells it.

I agree but in general, it is easier to clean up. All I have to do it look at my BP rifle.

[JDcluster]

I've been using some 777 which is like a hybrid of pyrodex.
You definitely have to confine it better!
I have used it as a back up to a BP charge and by itself as the primary charges.
One rule of thumb I've been using: use a bigger charge to be safe.

I've had one 1.8 to 2.0 gram apogee charge fail in a 5.5" rocket but, the BP main charge fired zippering the rocket.


JD

[Zeus-cat]

I have used both. I would use black powder if you can get it. Pyrodex will work fine if black powder is to hard to get.

[GaryT]

I'd rather pay double for 4F than use pyrodex, But thats just me.

[grouch]

I am no expert on the subject at all. In fact I only have 2 dual deploy flights under my belt and I am still trying to sort some of this stuff out but I do know from my black powder shooting days that there is no substitute for BP when it comes to power and accuracy. I used to get much more repeatable performance with 3F BP. In shooting, you only use 4F for priming pans in flint lock rifles and pistols. That being said, I simply trust BP more than I would ever trust a substitute. When you think of all the hours put into building these things and the things that could possibly go wrong, there is just too much to risk by not using the best. I watched my Nuke ProMaxx rip off the pad and scream all the way to apogee, I shudder to think of the hole it would have dug if didn't separate because there wasn't enough expansion from the charge. Not worth screwing around with it.

[EeebeeE]

I initially bought 777 pyrodex, and I can tell you it is as finely ground as 4F. I've seen articles where it has been said that using pyrodex in plastic canisters that are then wrapped tightly with electrical tape will delay the explosion long enough to make sure that all the powder is ignited. But I still ultimately found a pound of 3F and will use it instead. I think the issue for smaller DD rockets is that pyrodex is formulated to work well in larger quantities, but not necessarily smaller. Charges for even a 4" rocket are less than half the amount of pyrodex used for a .50 cal. muzzleloader.

So if you are using 75-90 grains (3.75-4.5 grams) of 777 in a muzzleloader to shoot a 0.50 cal. ball, it works well. But in a 2.26" dia. rocket like my Nuke Pro Maxx, I am only using 0.5 grams, or 10 grains of explosive. If I switched to pyrodex, I am using an amount that is too small for the intended use of the charge, which probably results in the unpredictability. Keep in mind that 1 gram = 20 grains. So I would not consider using pyrodex until I needed a charge greater than 3 grams, or 20 grains.

I suppose the next question would be can we mix the two together?

[Polyalcoholic]

1 grams is closer to 15.5 grains. ref. http://www.engnetglobal.com/tips/convert.aspx?catid=3

The idea of mixing BP and Pyrodex is interesting. Sounds like a fun science project.

[cwbullet]

hmm. Maybe that is a good experiment. Maybe a pressure catheter.

[Rocketjunkie]

Has any one tried igniting the powder at the 'open' end of the charge. Using a rigid container such as a capped pipe nipple, place powder (Pyrodex or BP), then igniter, fill with wadding and tape. The idea is to ignite at the 'open' end so the flame front moves toward the solidly closed end of the charge canister. This way any unburnt powder would have to get past the burning powder to escape. Might work in high altitude charges also, try in vacuum chamber.

[BLKKROW]

This is what I do when I ground test.

I take an old lid from a can of vegtables/beans etc and bend and cut it into any shape you want then fill it up and put a single layer of tin foil on the top that way then the Pyrodex ignites it pushes and uses all its power up instead of out.

[rocketsmith]

I use pvc end caps as my charge wells. I then silicone a 3-4" piece of 1/2" copper pipe into the end cap. I use flash bulbs as the ignition source so, bulb in the bottom, then 2 grams of Pyrodex, then a paper cap pressed down tight to the powder. Fill the remaining tube volume with cellulose wadding, tamp until firm then tape over the end of the pipe, 3 or 4 layers. Then I wrap the end of the pipe with a few winds to secure the tape cap. I have never had a failure to fire and burn completely since using this method and I get very energetic deployments. Basically I made a gun with no bullet.

[qquake2k]

Black powder in FFFFg is an extremely fine grained compound and burns much quicker.

Goex 4Fg seems to be the BP of choice among the local rocketeers.

Did you ever find a source for BP?

[o1d_dude]

Did you ever find a source for BP?

Yes. Jack G.

All i have to do is drive down and pick it up.

[iter]

Yes. Jack G.

All i have to do is drive down and pick it up.

Hey, maybe I can buy some from you if you get more than you need.

Ari

[AlfaBrewer]

I suppose the next question would be can we mix the two together?

One of the basic rules of reloading ammunition is never mix powders. I would think this could safely be applied here.