Shelf life of whistle motors

[OldMarine]

I just dug through my PMs on FW and found that I got the milled stuff from MikeB and it's American. Long gone unfortunately....

[August]

Old, contact Steve Kursinsky on Fireworking.com. He still has some Swedish for sale, I believe.

[dynomike1]

I have been meaning to get back to this. No resonance cavity. I think it is probably the Perchlorate.

I would try to reconsider storing any potentialy explosive composition inside a sealed metal container, it's a good recipe for an accident.

​Why would you think that a sealed SS plastic coated container wouldn't work? I have never gotten static from SS.

(Just asking) NJ

Edited November 28, 2016 by dynomike1

[NeighborJ]

Mike I may just be paranoid. I don't store any potentially explosive mixture in metal containers because of the possibility of shrapnel if it would ignite. It's unlikely to happen but there is always a chance of contamination from other comps around the shop no matter how clean you keep it. If there is a fire in the storage area those metal containers would be impossible to approach with a fire hose. At least with ziplock bags in plastic bins they would be more likely to flare up instead of confein but if they explode anyway, at least there won't be shrapnel. IDK I guess it's just preference.

[dynomike1]

Ok i see what you are saying. I have a big wooden box outside under a carport away from everything that i store chems. in. except for what i am using at that time, most in plastic some not. You know nothing in pyro is fool proof but you do the best u can. Every since i had some winchester powder catch fire in a plastic bottle one time.(10' away) in my shop i am kinda leary of some types of chems in plastic. That wont happen again. I figured an explanation was in order why i asked you that. Maybe this conversation will help someone else one way or another.

[August]

Zip lock bags are horrible for fire resistance. Slightest spark will melt through the bag and ignite the contents. Cardboard tubes work well and thicker plastic containers.

 

For those who don't like to store comps in metal container, better hurry and empty out your magazine. Intentionally setting something off in a metal container is a completely different story.

[NeighborJ]

Ziplock bags are horrible for fire resistance,but are great for keeping the comp from spilling around in the cardboard or plastic container, which is in the metal mag.

I certainly wouldn't want a fire but I treat all comps as if it is going to lite without provocation. By not using metal containers it ensures that I have one possible bomb(magazine) rather than ten bombs within a bigger bomb, each one with the capacity to kill or injure.

I've seen oxidisers eat stainless steel (quickly) due to moisture so in a humid environment such as many of us are I'd personally avoid using it. I am paranoid about getting certain chems contaminated, such as Chlorate, sulfers and AP. So in an environment where it is remotely possible I treat that possibility as a likelihood.

[Fotia]

So why is it that consumer whistles such as rockets, chasers, & Saturn missiles last a long time without being in a sealed container?

[NeighborJ]

Fotia the answer to your question is not strait forward and I've never heard a good enough explanation to satisfy my curiosity. But I do believe the consumer whistles are derated so they aren't under as much case pressure as our hobby motors. It has been suggested to me that consumer motors have an inert ingredient added such as perlite to cut the case pressure without sacrificing sound, IMO it may also give it a small cushion to absorb the relaxation of the fuel grain as well as any thermal expansion issues when storing in wide temperature swings.

[ExplosiveCoek]

They're usually made more like end-burner style, and are therefore not as prone as the core burners we make to CATO's. They have to be more on the safe side, because they are mass producing and shipping them everywhere. We know that it is not smart to bounce your rockets, or do other stuff that causes damage/cracks to the fuel, and therefore can lift larger payloads with smaller highly aggresive rocket engines.

 

That being said, I've seen quite some commercial rockets go bad due to moisture (not enough power anymore).

[OldMarine]

I was reading a thread somewhere in which a poster stated that some patents on Chinese whistle showed that wax was being used to phlegmatize the fuel so as to mitigate moisture absorption and to make the fuel more cohesive.

[dagabu]

So why is it that consumer whistles such as rockets, chasers, & Saturn missiles last a long time without being in a sealed container?

 

This is likely to be one of those questions that comes up every year, It has been answered by Chinese manufacturers, US manufacturers and innumerable hobbiests. Commercial whistles (all are only a few grams of whistle) are gang pressed in a single stroke. This allows the whistle to not have hard and soft spots in the grain and as mentioned already, they are all nozzleless and are made like an endburner where there is only a small cavity at the end.

 

A phlegmatizer is always used commercially to block moisture BUT the amount can vary widely! As can the type of phlegmatizer.

 

J also hit the ole nail on its head, they are severely derated.

Edited December 24, 2016 by dagabu