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Detection of AP in consumer FW


Sulphurstan

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I have a consumer FW (rocket) where I would like to know if  AP is present in the composition.

The compressed power is white, contains sodium (yellow flame), and a chlorate or perchlorate as oxydizer.

How could I find which is the oxydizer?

 

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There is a very little chance it contains AP since it would be too expensive and too difficult to use in consumer fireworks rockets.

Why do you think it could be ammonium perchlorate?

What is the brand and type of rocket?

It is most probably based on potassium perchlorate, perhaps in combination with potassium nitrate.

If you mix some of the propellant with a small amount of water, so you get a concentrated solution of what ever ingredients there are, and add some magnesium powder you will immediately notice bubbling by the formation of hydrogen gas is ammonium perchlorate is present.

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Another common spot test is to slurry a small sample of the composition in question with sodium or potassium hydroxide and look for the telltale odor of ammonia.  There are other more intricate and less smelly tests, but that is probably the simplest.  

This to me sounds like a commercial whistle rocket.  Is that correct?

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Thank you for these tests I'll make. I like the KOH NaOH one, the smell of ammonia is easy to detect.

These are motors from amateur rocketry in fact.

 

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Motors for amateur rocketry will likely NOT be classified as fireworks and from some experience could well contain ammonium perchlorate. Why does it matter? If they are "Articles Pyrotechnic" the rules for fireworks will not apply. 

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Yes Arthur, I think you're right, amateur rocketry motors CAN be APbased.

Thing is, I may use some of these motors as rocket to put a shell on top, and need to create the passfire, which I usually make with nitrate based compositions. I shall make a picture or two to explain better....

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I see no reason why you should not have two passfires! one for the motor and one for the payload. You could also consider a flammable (but not explosive!) NC lacquer to chemically separate the two incompatible mixtures. The typical rocket motors I'm aware of (UK based) need a nozzle and a pressure casing, which must fall to earth after use-usually on a parachute.

I'd stay far away from non firework items, at least we know how a firework rocket behaves, and know it's incompatibilities.

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Yes Arthur, I'm ok with your opinion, not mixing Rocket motors and fw motors, but I'm not able to make my own BP pressed motors (not possible to make some testing to tune the mix, the motor, the nozzle.... out of NYE and national day because location is too much near the neighborhood and because of fw acceptance in my country), so I switched very early to a certain type of D-9 motors which can lift up to 3 inch shells. Never had problems with the passfire composition, but I want to know, to make it "100%" sure.

I can send a couple of pictures if needed.

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Do a web search for Estes D9 composition I vaguely remember a table showing Estes compositions. Estes are unlikely to tell you about the works of their motor and the www isn't always right. Can you consider using a layer of nitro-cellulose guitar lacquer as a flammable barrier between two incompatible compounds?

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  • 2 weeks later...

Estes doesn't make a D9 motor, only a blackpowder D12 (12N average thrust). And their motor design isn't really any secret.

SStan is in France where Klima, not Estes, is predominant. Klima makes a D9 motor series that's very popular across Europe, but use APCP (ammonium perc composite propellant) instead of BP--you can fit D motor power into an 18-mm C motor BP case. So yes, it does have AP in it. And aluminum. And whatever binder/plasticizer combination they use--very probably the common HTBP/IDP combo.

Like Estes' BP motors, Klima's D9s come either a 3, 5, or 7 second delay charge--unsure of the delay comp (it's bicarb-slowed BP in Estes motors) but the ejection charge it meets is BP (just like the small commercial APCP motors in the USA).

Klima also makes a D9-0 booster motor, which has no ejection charge but instead burns through to ignite a sustainer motor in an upper stage rocket (or converted to ignite a pyro load); these booster motors are simpler to convert to fireworking uses than worrying about removing an ejection charge and scraping out a (long) delay grain of a motor designed to eject a parachute.

Estes D12s will lift about 400g (including motor weight); you'd have to check performance tables for Klima D9s tho it seems Sulfur's probably determined lifting power empirically.

Edited by SharkWhisperer
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Thank you for these informations shark.

Regarding weight I just wrote it down roughly, didn't check my tables. I already fired d-9 motored 3 inch shells, but yes, they don't reach great heights, being pretty dangerous with an apogea at around 20-25 meters....

But for 2.5 inch shells, they are just great

Edited by Sulphurstan
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