And I should have been more clear with my comments about the paper
thingies. They are casting tubes, not casings. I make them myself and
have a decent assembly-line process for doing so (I have 6 mandrels and
do 6 at a time). Perhaps with some adjustments (lots more glue, for
example) you might get some screws to hold, but that's way outside my
experience. Also, I've never pressure tested them, so I have no idea
what they'd withstand (although I do put quite a bit of pressure on them
when I apply pressure to the propellant during casting).
In my comments about casings, I should have added that my way of
guarding against severe overpressurization (in addition to the pressure
relief valve I mentioned in my initial post), I use 4 very weak #6 grade
2 machine screws from Home Depot (made by Crown Bolt Company which is
now part of HD) to retain the nozzle. I have tested that config
hydrostatically numerous times and it seems to let go at about 600 psi
in a 2" casing. I retain the bulkhead with 8 grade 8 #8 screws (lotta 8s
there) which is good for about a gazillion pounds.
This is why my steel casings seem to last a long time--the nozzle
retention screws let go well before the casing is ever endangered. I
would imagine steel casings would last quite a while for you, too, even
with the metal additions to the propellant. Nozzles, however, may be a
different matter.
--Steve
On 8/21/23 10:28 AM, Kelly Jones wrote:
Thanks for the info! I should have been more specific with my question; in your post you mentioned paper casings, 1/4" wall thickness. I was wondering about your source for those, and how you retained steel nozzles in paper - if that is indeed what you were doing. I'd like to play a bit both with endburners, and with metal (Ti, FeTi) additions, and single-use paper casings with clay nozzles may be what I want to use to work around the destructive nature these would have on casings and nozzles.
I haven't exactly 'figured out' anything with blackpowder - I used to dabble in pyrotechnics, and was just using the standard materials/methods used in that field for blackpowder. I was also staying extremely small, staying below 1" ID casings - or what the pyro guys call "3 pound" rockets.
Kelly
On Mon, Aug 21, 2023 at 10:10 AM Steve Peterson <dmarc-noreply@xxxxxxxxxxxxx <mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
