20 replies to this topic

[JinxStar]

Hello, Im fairly new to the art of pyrotechnics. I had a question about an oxidizer. I need to burn magnesium. Since it needs such a high temperature, I was going to use Potassium Perchlorate to ignite the magnesium. My research says Potassium Perchlorate starts to burn at around 610-650 Celsius. Will the Potassium Perchlorate reach its combustion point with some simple Visco safety fuse? If not any input would be appreciated. Im unaware how hot that type of fuse burns. Rather than find out the hard way and waste material or do something stupid, I wanted to ask.

Basically im looking for a material I can use to start the magnesium. And that doesn't require a high temperature itself to start. Im not sure if I have all my terms correct. Simply put, Im looking for an oxidizer or material I can ignite with Visco safety fuse, which will reach a high enough temperature to ignite some pure magnesium. .. Sorry this is so long. Thanks for reading it and any help or information is welcome.

[Edited on 14-7-2003 by Richard H]

[Matt]

Umm, potassium perchlorate doesnt burn mate.

[JinxStar]

I read that Potassium Perchlorate does. But either way, that's why im asking before I try anything, mate.

Even if it doesn't all I need is a material that will burn at a temperature high enough to ignite the magnesium, but itself can be ignited with some simple Visco.

[Matt]

Sounds like a thermite job. Not sure if it would ignite Mg though. I know what ya could do with KClO4 and Mg to make it burn, but i think no one on the board would recomend it either.

-Matt

[Richard H]

Right, quiet in class!

Time to learn the basics.

A fuel is a substance which burns in the presence of oxygen to release energy.

For an example. Consider you have some finely powdered charcoal (An impure form of carbon). If you manage to ignite the charcoal it will smoulder very slowly.

For combustion to occur you need three basic elements:

1) A fuel must be present.

2) Oxygen must be present to sustain combustion.

3) Sufficient heat must be present to raise the material to it's ignition temperature.

In a pyrotechnic composition we make fuels burn very quickly by adding a chemical that is classed as an oxidant.

Oxidising agents or oxidants work by releasing oxygen when they are reduced. They act as electron acceptors in a reaction.

If we add an oxidant to our pile of powdered charcoal and mix, the reaction wil be much faster. Upon reaching the minimum activation energy (Ea) the reactants will begin to decompose to form products.

The oxidising agent releases ambient oxygen, thus the fuel mixed with it can burn very quickly.

Oxidising agents alone will release oxygen, but nothing will burn because a fuel itself is not present.

If you wish to light a pile of magnesium then mixtures containing chlorates or perchlorates will generally do the job. Many compositions burn in excess of 1000 degree's centigrade.

[Edited on 13-7-2003 by Richard H]

[Matt]

I assumed he was refering to a block of magnesium, is this correct?

[JinxStar]

The magnesium is a round chunk. Less than a 1/4 of a mm high and 5 mm circumference. I have been learning basic pyrotechnics for a school project. All of my terminology may not be correct. I appreciate any help.

A portion of the project I need a compound I can have atop of the magnesium slice and will generate enough heat to ignite the magnesium. But the compound itself has to be able to be ignited by Visco safety fuse. This is the only way the school will allow the project. I have most of the work done and its to late to change to a different one now anyway. All I need is a very simple compound or chemical I can easily ignite with Visco fuse but will be able to make enough heat to ignite the magnesium. Can anyone help?
Thankyou.

[pyromania]

flash powder would probably ignite it but im not sure :bounce:

[Gor]

OK I may not be the best to respond here but I do see that we are not answering your question.

I have lit magnesium ribbon with a match. The yellow part of a flame is around 1500 degrees (look up your black body radiation), the trouble with your block is that there isn't enough heat to get the magnesium block up to temperature (heat and temperature are of course different things).

I would have thought that your block would light straight off the visco, but if not a few shavings taken off it and placed between them should do the trick.

I suggest you try lighting a couple of shavings taken off your block, straight off a shorth length of visco to see what happens (without using up all your block). If it lights then do it again and put your block on top and it will light off the shavings.

I wouldn't get into perchlorate or other complexities. hope this helps

[Gor]

I have just read your post again and realised how small your block is - like a little wafer - and you mean 5mm diameter not circumference?

I would be surprised if that won't light.

[JinxStar]

Thanks gor. I did meant circumference, they kind of look like jacket buttons. I already tried lighting one directly with visco, sitting on top of it and once under it hoping it might do something.

I tried powdering one of the tablets too and lighting with visco. No luck either. The visco just burned into the pile and nothing happen to the pile or the magnesium tablet under it. But the pile did burn when I stuck a fireplace match to it. so I figured I need something hotter. That's why I was asking about compounds to touch off the magnesium. I don't all my lingo or technical terms. But that's all im looking for. Something simple I can set off with visco that can set off the magnesium. It seems simple enough but 3 days or research and nothing. So I looked for pyrotechnic forums. and here I am.

Knowing a match will work stinks. Because rules say I have to use visco safety fuse to do it. If worst comes to worst I will take the tops off matches and powder them. But it seems like it cheapens the whole project to have a main part done basically with a book of matches.

[adamw]

I wouldnt do any match head powdering, not entirely safe. Does this 'project' state 'Visco' green fuse only? If an ignitor cord like ICI PIC (Plastic ignitor cord) can be used, this may do the job. It burns a lot hotter and more vigorous than visco. You could always try a starting mix of maybe magnesium powder, or a metal powder / oxidiser comp (such as alu powder / KNO3 etc)

[JinxStar]

My professor overseeing the project just read for the shool reg. book. So he said use visco. If its a very safe fuse type im sure i can get him to okay it. But I have never heard of Plastic Ignitor cord. And any websites selling it seem to be UK.. I doubt with me living in the United States importing fuses w/o any type of permit is legal.

[Rhodri]

Hi Jinxstar

If you live in the US you could visit

CLICK HERE:

It's much easier for you to obtain cat. 4 components in the US that it is here.

Check out their fuse section.

[JinxStar]

Thanksyou Rhodri. What are category 4 components? Also what fuse am i looking for?