PyroChemistry

[Caustic]

of the iron oxides, which one is black and which is red?

[budullewraagh]

[math]Fe_2O_3[/math] is red and [math]Fe_3O_4[/math] is black

[math]N_2O[/math] isn't an oxidizer; it's a reducer that yields nitrogen oxides.

as for liquid/gaseous oxidizers, try hydrogen peroxide for a liquid. bromine works as well, but it's really nasty stuff and not terribly effective. same with chlorine gas except it's a bit less nasty to work with but annoying as hell nonetheless. also, iodine sublimes but it's poor. really, you dont want to use halogens unless it's fluorine, in which case you really dont want to work with it (and astatine too for obvious reasons).

[Caustic]

of the red and black iron oxides, which one would work best as a burn rate catalyst for KNO3 based rocket propellent? Would it be black because of the extra oxygen? or red because of the higher oxygen:iron ratio?

[Gilded]

For thermites I always see "use Fe3O4 if available" or something like that. However, I think the O3 produces more heat.

[Caustic]

would the Fe2O3 decompose at lower temp than Fe3O4? that seems to be the trend with oxidizers such as KClO3 vs KClO4...

[budullewraagh]

i would imagine that [math]Fe_2O_3[/math] would be your best bet

[Von Klemmung]

Hey where'd that LUVLY thread go?

 

Okay, I'm a couple months late on this forum, and have taken my time reading the threads from oldest up.

 

Now, I have a couple of replies to the earlier posts on this thread.

 

I hope they might prove useful.

 

(This might take a while to read, but just hang on)

 

1. YT, you mentioned an electric igniter with a coil or spring-shaped bridgewire. Why the coil shape? Anything to do with the inductance of the coil making it heat up faster or easier on a lower voltage?

Otherwise, I've only read about and used short, straight bridgewires.

 

2. Regarding dextrin. I make this stuff in quantity when I run out of it. Any problems making it (apart from time and temperature) might stem from the confusion between flour and starch. In Denmark, we can get both corn flour and corn starch. The purest starch type is the one you want. As we can also get potato starch for a third of the price of corn do. that's the one I'm using.

BTW, try looking at it closely before and after baking (good light and maybe magnifiers).

Anyway, after baking, it should make a CLEAR brownish paste with water. If it is still foggy or opaque, there's still some more unconverted starch in it.

 

3. Regarding filling rocket cores with black powder.

Okay for smallish rockets. For larger or serious ones, use a pyrotechnic igniter (one that creates a greater puff of hot gas).

Google Richard Nakka. He has good info on rockets.

 

4. Regarding coring of rocket motors.

This all depends on a multitude of factors. Eg. Casing strength, fuel power, nozzle size etc.

The topic is called Grain Geometry, and much can be found out by Googling Richard Nakka. Also check James Yawn (yes) and his page on RCANDY.

 

5. Regarding Red gum.

Initially, I thought this is what you get when you don't brush your teeth OK.

But I found this on the net. http://onlinedictionary.datasegment.com/word/Red-gum

Actually, it seems to be a naturally occurring wood sap from a Eucalyptus-related tree.

 

6. Regarding Spud guns.

Could anyone please think up a way to deplete potatoes??? PLEASE!

I would love to be the first on my block to fire Depleted Spud Rounds

 

7. Budullewraaagh, this one's for you (hope I got the number of A's right).

Okay, N2O might not in itself be an oxidiser, but AFAIR N2O releases oxygen upon heating, no? Also, it is used as the oxidiser part of the fuel in many hybrid rocket systems. As for the fuel part, I've heard of acrylics, paper and (believe it or not) BOLOGNA!

 

Whew, I hope it was as good for you as it was for me.

 

Could we please get the pyro thread up and running again (hopefully without the obvious explosives and "where do I buy this"-questions)?

 

Nothing wrong with lack of compounds, but let's be chemical types and synth it!

 

------------

"We're all individualists!"

-"I'm not!"

[budullewraagh]

ok, you added an extra A but it's ok

 

N2O is used to oxidize organics at temps above 300 celsius. it also can be oxidized easily enough to make nitrites. it's versatile in that sense. oh, and it is the anhydride of hyponitrous acid

[jdurg]

It's also more commonly known as 'laughing gas'.

[Von Klemmung]

Erm... Yup!

 

And used for boosting petrol engines and whipped cream, if I remember correctly.

 

Thanks for the additional info, Budullewraagh. Hat off!

 

You KNOW your compounds!

 

Any of you guys have an idea, why YT2095 suggests a coiled bridgewire for electric ignition?

 

Or maybe YT2095 himself?

[pyromaster22]

lets discuss the rocket fuel H3, this is potassium chlorate/charcoal in a ratio of 77/23 respectively (from Takeo Shimizu) this propellant is often changed to naclo3/c because the sodium chlorate is easier to obtain. so what are peoples experiences with it. it obviosly doesnt need a core as it burns fast enough anyone have comments on performance or safety precautions?. is it safe to ram?

[YT2095]

wow, that`s quite a thread bump there, PYM22!

yes I`ve used this mixture to reasonable effect in rocket engines myself, but you REALLY have to get the nozzel dimensions Perfect!

 

Any of you guys have an idea' date=' why YT2095 suggests a coiled bridgewire for electric ignition?

 

Or maybe YT2095 himself?[/quote']

 

sure, a Coil is inherantly more stable when it comes to movement (when drying and heating) and it also allows for greater surface area for the ignition material to adhere to, as well as being compatible with a whole range of different ignition systems

[RyanJ]

How did I miss this old thread when I was reading throught eh archives? Thanks for digging this up, I have some reading to do!

 

Cheers,

 

Ryan Jones

[chemfreak]

the vast majority of us are responsible adults

 

im 11 but a responsable boy scout who wants them to make a pyro merit badge

[Von Klemmung]

Happy new year!

 

I just decided to spi... erm... SHARE a discovery about electric igniters with my fellow experimenters.

 

I've been mulling over YT's "ignition coils", and decided that using a car battery was overkill (for me, anyway).

 

So I've checked pages with nichrome wires and christmas bulbs yattata yattata...

 

I even found a few rocketry sites, mentioning the need for blowing a cap with a battery contained in the nose cone of an amateur rocket (more bulbs).

 

What I wanted was something that would fire on say, 3 volts, through 5 metres of regular mains leads.

 

And I got it!

 

Shamelessly adopting existing technology, I came up with a design needing only aluminum foil, cardboard, a glue stick, some adhesive tape and some crushed/sanded match heads.

 

Cut out a piece of cardboard (say 4x4).

 

Cut out a piece of foil (4+ x 4+).

 

Coat one side of cardboard with glue and fix this to one end of foil.

 

Now coat the other side of cardboard with glue and fold foil over.

 

Next, cut the sandwich into strips WITH THE FOLDED END AT THE END OF THE STRIP, DAMMIT! Maybe 1/4 or less wide, depending on application.

 

Now, trim the folded end with a pair of scissors, so there's a "bridgewire" of approx. 1 mm. left (cut the corners).

 

Make a pile of flashy powder on a piece of sticky tape, lay the bridgewire in it, close the tape, and hey feckin presto!

 

You've made something like a tigertail igniter (or whatever they're called, we can't get them in Denmark anyway).

 

To fire it, apply positive charge to one side and negative to the other, providing your card is thick enough, so the two layers of foil don't short.

 

I've fired these babies on a single rechargeable on short leads.

 

Okay, 4 D recharg's at 5 metres, BUT I COULD TRIM THE BRIDGEWIRE, SO THERE, NYAH NYAH!!

 

---------------

 

Still working on a BP substitute using starch and/or dextrin.

 

For fuses and rocket motors, the results are promising.

 

---------------

 

Now start talking pyro!

 

I'm especially interested in advanced projects with simple means.

 

Perchlorates are VERY DANGEROUS over here, but we can still buy AN in 25 kg. sacks (not so with KNO3).

 

Maybe no Danes know how to make detonators? Or critical diameters of AN/ANFO?

 

Hmm, I guess I must be a foreigner, then.

[akcapr]

ANother good ignitor are christmas tree bulbs. THey will go off on like a AA battery. What you do is you break off the tip of the christmas bulb (heat the tip in flame then dip in water and it will come off easily) then into there u pour some blackpowder or what have you and then just connect it to your battery. works like a charm.

[KFC]

Use a broken christmas light and a 9DCV battery (the square).

[TATER]

If you need pyro mixtures i got a zillion of them

[Sanguine]

What`s up? Post them.

(numbered please)

...

[Freirec]

The Smoke bomb recipes in this website are great, but it is hard to find saltpetre (potassium Nit.). If you go to a drugstore and ask for saltpetre from behind the pharmacy counter, it costs about $2.19 for 6 ounces. Yesterday I tried combining the two outdoors on a campfire, it lit up. Nice Chemistry! I'm going to try to melt the sugar indoors, them add the saltpetre, after it is carmelized. 4 cups caramelized sugar to 6 cups saltpetre.

 

I'll post my 2nd try outcome in a couple days.

 

My smoke bomb mixture/creation worked. I used 4 oz. of sugar, and 1/4 cup of light corn syrup. I mixed them touroughly together, and heated them on my kitchen stove for about 1o-15 minutes on my kitchen stove, stirring constantly.

 

 

NOTE: Not stirring causes the mixture to become black, smoke, and it won't work for the smoke bomb.

 

 

The mixture should be done once it reaches a peanutbutter color. If the peanut butter color becomes red, thats ok. Its red from the light corn syrup colling down. Right when u take it off the stove, bring it outside and pour in the 6 oz. of Potassium Nitrate. It will go back to peanut-butter looking, and will cool down and harden fast.

 

Pour into containers, add wick, cool down and VOILA! done.

 

Works great, smoke, fire column (1-2ft. high)

 

TRY IT!

[YT2095]

and the Use for such things in everyday life would be?

[Freirec]

and the Use for such things in everyday life would be?

 

Why do I need a reason for everyday life. I use my smoke bombs for paintball/airsoft gun fights, throw out a couple smoke bombs, and you have cover for 10 minutes.

 

Also, if you add 1/2 cup of cornsyrup instead of 1/4 cup, they become perfect for sticking to peoples clothing, walls, or any other obstacle.

[pyroman]

what is the simplest way to make a cell phone ignitor? not a terrorist, jus curious

Edited August 1, 2010 by pyroman

[Mr Skeptic]

what is the simplest way to make a cell phone ignitor? not a terrorist, jus curious

 

It's actually extremely simple. However, it is too expensive for practical use unless you really need it to work independently, which seems unlikely. Also it's probably going to be only 1-time use for said purposes.

 

When I played as a kid I would ignite things at range with an old car battery, an electrical cord, and a thin wire from a window screen as a filament. This was really cheap and reusable, and allowed me to make things go boom from a safe distance. But that was in Paraguay; here in the land of the free I don't think it is allowed nor wise to do.

[First↔Cause ♀]

Just wondering if there are any other pyrochemz out there....

 

if there are... lets start a thread... on pyrochem only...

 

btw just wonderin what is the easiest flash to make,... like with the easiest ingredients to obtain...

 

post lots

 

chill out and have fun

 

 

Deletia

CAUTION→ Keep in mind that NO flash mixture is 100% safe. And, it is not legal to make,ignite,or possess.

 

!

Moderator Note

Not safe, not legal => We aren't ging to discuss it then.