823 replies to this topic

[rocketpro]

Yes, Potassium perchlorate is fairly stable compared to chlorates, and very stable compared to some other oxidisers (which are too dodgy to find firework use are they not?).

I also agree that many people do have an belief relating to some mixtures (including both perchlorate/sulfur and chlorate/sulfur) which exceedes the real danger. However this provides a margin of safety, and is not a bad thing. Aditionally, since devestatingly powerful flash powder using Potassium perchlorate and Aluminium can be made, which can perform every use that we have for flash powder, including breaking small crossettes, I believe the addition of Sulfur to the flash powders to add significant danger far beyond the reward.

I have no doubt that they have measures in place to make what they are doing safer, such as anti-static measures and pure chemicals, and the screen is probably not made of a dangerous material, but I would not be happy doing what they are doing. Professionals have bad practices and die too.

Well, one thing`s for sure, if that lot went up while he`s sifting, he wouldn`t even hear the bang!!

[phildunford]

Don't know where these guys learned their craft, but they won't live to be much older if they carry on like this! Never screen flash - it's asking for trouble. Any company with the slightest knowledge of the dangers would be mixing in a rubber tumbler in an unattended remote building.

70/30 flash is powerful and about as safe as you can get so as Seymour says, why add sulphur?

[pyrotechnist]

Plus no proper respirators, no gloves, no cotton overalls, no glasses, no anti-static wrist bands or clothings etc. Bad practices! The worst is letting a novice mix flash.

[blasterbert]

OMG ive just been looking at this thread and im shocked.there is no need for ppl to make this stuff with anything other than perc and al 70/30 mix.i definately agree with phil about these people could cut there lives short.sulfer,chlorates,permang!!!i say NO NO NO its not needed.normal mix of perc and german super H makes very very powerful flash and all other formulations should be thrown out the window.bad practice = loss of limbs or death.there is my rant for the day.

[Potassium chlorate]

Plus no proper respirators, no gloves, no cotton overalls, no glasses, no anti-static wrist bands or clothings etc. Bad practices! The worst is letting a novice mix flash.

It's weird that they use no glasses and pretty bad respirators, I agree. I only use simple respirators if I mix small amounts of a composition and it's not very toxic.

[starseeker]

After all that,he then filled the end of the salute with hot melt glue,rather him than me.

[crystal palace fireworks]

I think this would make a good training film/presentation to show newbies how NOT to process firework comps without proper safety measures in place!

[pyrotechnist]

Then again we slate this guy though I see maltese people mixing colour based comps and all sorts of comps with bare hands and literally they are covered in comp as they brush it over the screen and hand fill drivers etc. The Chinese also do the same thing and do not work to much safe standards at all, would say why a firework factory goes up in smoke every week if I remember correctly.

[Mumbles]

Youtube is making my browser freeze at the moment, but I think I know what video you're talking about. It's from an American show called "Dirty Jobs" right?

It is common practice to screen flash. Ask every well established big shell maker, or try diapering that much flash. Diapering just doesn't mix flash as well. I avoided it too, but I've taken to screening and wont go back. I've heard from several manufacturers on the matter, and they ALL screen their flash powder. I don't like the sulfur addition, but it makes sense from an economic and performance perspective. Also to be fair, if you're doing it correctly, its more of a sifting, and not screening. Any scraping or rubbing is really a no-no, despite what is in that video.

I am not condoning letting the newbie who doesn't know what he's doing attempt it, but that is how commercial manufacturers do it. I've actually heard that the empty cement mixer opperated remotely is a bunch of BS. It's at least a running joke from a group of well known large shell builders who really heavily emphasize salutes in their products. It's just a glorified diapering, and that is already addressed.

Taken directly from the author of the Fulcanelli articles: "Diapering is for babies".

[pyrotechnist]

Well as far as I am concerned if fireworks can be bashed around in transit, miss handled, stacks of them falling down in factories while making them and yet none go off that contain flash then it isn't as sensitive as people want you to believe. Yes dont get me wrong its sensitive and dangerous but only if you are stupid and miss handle it. Even if the cement mixer theory is true or false if it is true then why haven't they gone boom? Anything can become sensitive if you start smashing pieces of iron into it, hitting flash with an iron hammer is not a good way to find how sensitive it is, wood would be a much better non-sparking choice. Of course your going to get an ignition if you smack an iron hammer on a pile of flash against a concrete surface as the dam thing sparks!

Thinking of it wouldn't diapering cause more static due to the particles rolling around on the papers surface?

Be safe with flash but not to safe, its like driving to fast but then driving to slow both will cause an accident.

[BrightStar]

Some of you may recall this:

Flash mixing accident at PGI meet

Remember, accidents do happen...

Edited by BrightStar, 23 March 2010 - 02:26 PM.

[helix]

I would suggest that it comes down to assessing the risk.

By assessing the likelihood of an accident and the severity should an accident occur the level of risk can be estimated. The reason for the initiation of an accident in this case could probably be attributed to either an electrical discharge (either via static or other means) or the sensitivity of the mixture to shock. The severity should an accident occur is likley to be high so mitigation of the causes of risk by minimising the likelihood of either shock or static effects would need to be carried out.

Presumably the company featured on the dirty jobs series, has looked at the options available to handle the quantities of material that they have to deal with and have decided that screening is the most appropriate method for them. Given that they screen the stuff then it would seem that they perceive the likelihood of an accident occurring via shock as being relativley low and the risk from static etc as being higher as I seemt to recall that they kept the humidity high to reduce the chance of static build up.

I would be very surprised if any commercial orginisation dealing with such large quantities of flash had not considered the formulation and the means of mixing very carefully before putting their lives at risk. Does anyone know how flash was mixed in the UK or how Kimbolton do it?

[BrightStar]

By assessing the likelihood of an accident and the severity should an accident occur the level of risk can be estimated. The reason for the initiation of an accident in this case could probably be attributed to either an electrical discharge (either via static or other means) or the sensitivity of the mixture to shock. The severity should an accident occur is likley to be high so mitigation of the causes of risk by minimising the likelihood of either shock or static effects would need to be carried out.

Static is always a bit of an unknown factor. Even working in fairly high humidity and avoiding the synthetic clothing, the human body makes a reasonable capacitor and you might just stumble upon a ground path. Flash really is very sensitive to electrostatic discharge.

As regards commercial manufacture, I believe that mixing larger batches infrequently, rather than smaller batches often, is common. As you say, given the certain severity of an accident, minimising the number of batch mixing operations is one approach to minimising the risk.

[crystal palace fireworks]

In addition to what has already been mentioned on this topic, I would like to see added safe guards when screening on a large manufacturing scale.

If possible,..... personally I would like to see some form of R&D along the lines of curtaining around the trays to help reduce atmospheric dispersal of comps into the surrounding air, along with a curtained/funnel hopper device to dispense comps into trays, as well as a remote control sifting trays ( a bit like a concrete vibrating table when you make paving slabs done via camshaft set up), all this could be done in a remote setting to help reduce human contact/fatalities.

[portfire]

I think that we (the hobbyist) should realize that were not going to be mixing that amount of flash, and should stick to Diapering, simple as.