neil_w, thanks for the tip!

tbzep, good to know--we don't currently have and old casings, but we'll watch for some

ghrocketman, It does seem that a lot of people use PVC cases. There are also other non-PVC plasic options, but I don't know if they are any better. PVC can itself be a fuel, so it also makes some sense. I'm having a hard time finding safety infor on zinc/sulfur fuels. Any pointers?

tmacklin, I was wondering abount doing that, and of even wrapping our own paperboard with glue. we'll look for West Systems epoxy, too.

So I finally found MSDS info on our Potassium Nitrate source. It is 99% KNO3, 1% Calcium Stearate.

I know that Calcium Chloride is a fire suppressant, and since Calcium Stearate is also a calcium salt, does it have a similar effect? If so, it's going to be a pain to remove, since it is also a crystal.

As always, thank you everyone!

You are not going to find much in the way of "safety" information for zinc/sulfur propellant due to the simple fact it is NOT SAFE.

You are on the wrong forum. There are friendly folks who might give you some casual advise here, and maybe a couple here (who aren't talking) with actual expertise. It looks like you established an account here just to talk about sugar rocket propellant. No big a priori deal with that. But when you have to ask "...is calcium stearate like calcium chloride because they are both calcium salts?" I'm calling out "BS". I think you are too uneducated to be cook book mixing up propellants in your garage and trying to load it into cases. You're going to blow yourself up. At the very least your going to get the stuff all over your clothes. Wear gloves and an apron. Sheesh.

And stay the hec away from zinc/sulfur micrograin.

I agree with Wolfram. This is not the right forum to be asking questions about amataure rocketry motor making. Zn/S is not something you really don't want to mess with. All in all, if you aren't taking extreme measures to be safe, you can win a Darwin Award. Play it safe at all costs.

Yeah it's essentially "flash powder" is it not... basically ANYTHING will set it off.

I think the problems with your motors are due to some error in the process... there's a video on YouTube of "The King of Random" where he makes similar motors. He uses the gray PVC hose nipples to make his motors because IIRC they're not as "brittle" and prone to shatter as regular PVC... IIRC they'd crack in two before they shatter. They say not to install air lines in shops with PVC (which I read a year after I'd installed my PVC air system) because if the pipe breaks under pressure basically it "explodes" with fragments of PVC blown all over the shop by the force of the compressed air behind it propelling it as it expands. Water and other liquids don't compress, so essentially if a water PVC pipe breaks the pressure is "instantly" relieved and therefore does not "propel" or continue to exert force on the pipe to shatter it into smaller fragments like air does.

Anyway, I haven't replaced my air system and it's been in there for most of 20 years... when it comes to air systems in shops they recommend either steel pipe or flex pipe (essentially, PEX or the black poly tubing with gray fittings...

Later! OL J R :)

It varies. It took effort to light it with a Bunsen burner to demonstrate synthesis reactions when I taught science. I mixed it on a small square of paper and set it on a mesh screen over the burner. I seldom had the perfect mix, which I recall was 6 to 1 by weight, but after the first time weighing it out, I always just estimated the size of each pile. It lit after the flame got on it a few seconds and provided quite the show, stinking up our whole wing. The other teachers hated it, which delighted the kids and myself. :cool:

The more fine the powder, the easier and quicker it went up. I used flowers of sulfur and I don't recall how fine the zinc was, but I didn't try to mill it down any finer. IIRC, it can be friction, static and shock sensitive to some degree depending on how it is prepared, particle size, the phase of Saturn and Uranus, how you hold your tongue, and whether or not your cat has recently puked up a hair ball.

tbzep basically described ZnS to a tee.
It even under the best controlled conditions is very often unpredictable. That is what makes it so unsafe, if not downright foolish to use. There are so many better alternatives.
There is NOTHING good I can say about using ZnS for ANYTHING.

Good to know
 

Okay, thank you everyone for your responses!
I do understand the instability of zinc/sulfur, and I would like to point out that if we were not taking safety precautions, I probably wouldn't be asking about safety concerns. :)

I know that most if not all of you are dealing with many other and more advanced topics, but I appreciate your time on this!

tbzep, that's good to know. I knew it could be unpredictable, which was why we hadn't tried it.

ghrocketman, I am curious what "many better alternatives" you might suggest. Good to know about the lack of safety though.

luke strawwalker, Thanks for the tip! We have seen several "The king of random" videos, although they provide minimal detail in certain situations. We did our best to follow those directions step-by-step, but had the same issue. I suspect it is a chemistry problem. We will consider and try looking for the hose nipples you suggested, although right now, the PSI our white mix generates is barely enough to even measure.

astronwolf, A bucket of cold water never hurts, and I do appreciate your concern. We are doing our best to take precautions and take it slow. (And yes, gloves and aprons are involved, as well as fire extinguishers, and more) As for blowing ourselves up, that is why we are talking and researching, instead of just trying blindly. One of "the right forums" couldn't help, which is why I was seeking some varied advice. If you have suggestions as to where this should be asked, we welcome them. Meanwhile, we are doing reading (offline as well as online). We entirely understand that the smallest chemical change can alter the molecule's properties immensely. It was a guess based on my lack of understanding of calcium stearate.

APCP and ANCP are far safer alternatives to ZnS.

Messing around with ZnS is JUST PLAIN FOOLISH.