Ejection Powder?

[MontanaSoftware]

Bob and Teddy ... thank you for your advice and information. I've read it carefully, and appreciate your desire to help.

I had no intention of breaking forum rules ... so I won't be discussing crimson powder at TRF again. I'll use other forums to discuss learning, experimentation, and growth. I'll use TRF to discuss commercially available rocket kits and mass-produced motors.

Take care, and best of luck to all.

Thanks!!

 

[midpower_madness]

I prefer GOEX Traditional FFFFg black powder. Pyrodex doesn't produce the same pressure for releasing big parachutes. Smokeless - don't use it. It's great as a propellent but isn't much use for releasing a parachute.

 

[bobkrech]

Most of us use Goex. Whatever you end up using, make sure you ground test it in every rocket. 4g of FFFFg != 4g of Pyrodex.

No. NOT gram-for-gram. It is a *volumetric* equivalent. That means scoop-for-scoop (or whatever measure).

This is what was posted above by someone,, earlier in this thread--

4g of FFFFg != 4g of Pyrodex.

Teddy

Bat-mite's statement is not correct for firearms. On a per weight basis, Pyrodex(R) is far more powerful than BP in a firearm. The volumetric density of Pyrodex(R) is altered so on a volumetric basis, one scoop of Pyrodex(R) is equal to one scoop of BP in a firearm.

It is far less clear for a rocket. While Pyrodex(R) is more energetic that BP on a per weight basis, it burns much slower than BP and it takes more energy to ignite. While an ejection charge of BP will readily ignite and totally burnout at sea level, the same volume of Pyrodex(R) or Triple7(R) if unconfined may not fully ignite but simply scatter unburned propellant grains, effectively reducing the gas yield per gram. It is for this reason you will not have reproducible results with BP substitutes unless you develop a self-pressurized confinement system to insure complete propellant grain burnout.

While you can get Pyrodex(R), Triple7(R) and even smokeless powders to work as ejection charges, it will take some development time to make a system that will work for you.

Bob

 

[ksaves2]

Simple, look around, search around, ask around and buy the most reliable remedy that's been proven time and again. Don't hurt yourself trying to make an inferior product when it's not worth the time investment or risk.
I got my home made ematches up to 100% reliability but it simply isn't worth the time investment to make them. Incidentally scratch builds were better than any kits out there but since there aren't too many issues in
obtaining, I don't bother anymore. I was scared that resources were going to dry up and "boned up" just in case.
Make a one time buy of 5lbs of decent quality 4F and one will be set for a long time. My first supply was a filled 35mm film canister a flier cheerfully poured full with his 4F powder. Kurt

 

[Jeffmhopkins]

Don't hurt yourself trying to make an inferior product when it's not worth the time investment or risk.

I'm not trying to encourage unneeded risk, but some people are interested in different aspects of rocketry (the aspects of amateur experimental rocketry). Personally I find great pleasure in developing my own propellants, motors, ejection powder and the like, and with proper precaution makes a valid hobby for those with the mindset for it. Now of course, pay attention to laws and regulation in your area yada yada (the same to all you non musket BP and ematch hoarders as well ) and practice safety first

And obviously ground test ground test ground test...

 

[Charles_McG]

In Bat-mite's statement '!' is a Boolean NOT operator. != reads 'is not equal to'.

 

[Handeman]

On the subject of BP, does 4F really work that much better than 3F? I can buy 3F locally, but I can't seem to locate 4F anywhere nearby.

Yes, both 4F and 3F will work. I've used both. The problem I've run into with 3F is because of the larger grain sizes, it takes a little longer to burn. I was finding small burn holes in my Nomex chute protector that I didn't get with 4F. My personal advice is to use a little dog barf between a charge and a Nomex chute protector. Maybe a little more if you're using 3F.

 

[Buckeye]

Yes, both 4F and 3F will work. I've used both. The problem I've run into with 3F is because of the larger grain sizes, it takes a little longer to burn. I was finding small burn holes in my Nomex chute protector that I didn't get with 4F. My personal advice is to use a little dog barf between a charge and a Nomex chute protector. Maybe a little more if you're using 3F.

Interesting. I also get some small holes in my nomex. I use 3F, too.

 

[Ez2cDave]

There's another article I found deep on the interwebs that is worth a read- format is a bit hard on the eyes, but it's also got some useful info for BP substitutes:

https://www.alaska.net/~aleckson/rockets/smokless.html

All credit to the original authors.

PDF of original information below . . .

Dave F.