Pratt Ejection Canisters

[Gary Mac]

Have there been a lot of positive experiences with the Pratt Ejection Canisters? From reading online, they are reusable and used to trigger ejection charges without requiring or consuming a separate electric match (sounds like you pack them full of black powder, and they have a wire that gets hot enough to ignite it in the back).

https://pratt-hobbies.com/products.asp?cat=38

Apogee sells them as well:
https://www.apogeerockets.com/Pratt_Hobbies

I've only found a handful of mentions online and on this forum, and not a lot of people seem to be using them. The main caveat I've found is that if the cartridges aren't completely full, the black powder can shift and not be close enough to the wire to ignite. Common remedies seem to be either only using them completely full, or packing some kind of soft inert material above the black powder to keep it packed down during flight.

 

[cwbullet]

On his site, he clearly states they are single use.

 

[Gary Mac]

On his site, he clearly states they are single use.

Ah, I missed that. Thanks for the clarification.

 

[jd2cylman]

Dog barf should hold the BP against the lighter...

 

[markkoelsch]

I have been using them for about 18 years. They work great. As mentioned, dog barf to hold powder in place, and a wrap or two of electrical tape over the closure.

 

[pendrin2020]

They're very very convenient, but you can also make them yourself at a fair savings. You can buy 100 to 1000 centrifuge test tubes on amazon for like $5-$20. After that, just buy a box of firewire ematches and break out the hot glue gun.