electronic igniter problem

[stanfield]

Here's a picture of my Detonator :
<img src="http://stanfield.150m.com/Bcap.jpg" alt="" />
As you can see, I use a filament lamp with a mixture of Nitrocellulose laquer + sodium chlorate + sugar
But, yesterday, I made 50 of them but I haven't put enough sodium chlorate+sugar and neither of them worked ! so I lose 40$...

Anyboy here has a pyrotechnie mixture wich works every time ?

I use 6.3 V/40 mA lamp...

Oh, I gorgot : I will soon made an order to ACROS Organics and I will buy 100g of sodium azide (for lead azide), do you think it could be reliable when lead azide is put in nitrocellulose laquer ?

a big thanx !

<small>[ May 21, 2002, 01:59 PM: Message edited by: stanfield ]</small>

[Zambosan]

!?? That didn't work? I'm contemplating dreaming about some DDNP for the first time soon, and I was under the impression that it was still pretty sensitive to heat! How does it behave with a flame? Your lamp is 6.3v; what type of power source are you using to energize it? You may need to apply a bit more voltage than the rating to get it to glow hot enough. How do your filament/NC lacquer ingiters work by themselves? Sorry for all the questions, I'm just trying to figure out what the failure mode is here, because this should be working... unless I'm really mistaken about the properties of DDNP.

Hmm, a little hunting reveals this:

"DDNP is used with other materials to form priming mixtures, particularly where a high sensitivity to flame or heat is desired"

So it's apparently less sensitive to heat than I thought. Which makes me want it even more. :D

At any rate, the sugar/chlorate mixture burns fiercely, but it does require a sustained flame to ignite, particularly when the hygroscopic sucrose has had a chance to absorb water. If you have access to NC grains (not ping-pong balls), I'd just use a small layer of that, or some fine grain black powder rather than a homemade pyro comp. just for added reliability & no nasty surprises.

[stanfield]

in fact, there is too nitrocellulose laquer, not enought chorate, so the is is a spark and nothing more... this doesn't ignite all the substance...

a few weeks ago, I made the same method but I put very large excess of sodium chlorate+sugar, they worked well but the filament was often broked due to the "concentration" of powder (chlorate+sugar) in the laquer...

otherwise, they worked very well, I heard a great BAOUM !

see ya !

[xoo1246]

I always use a pyrotechnical compositon around the filament, mostly fineley powdered matcheads, they never fail if the are constructed properly.
I have been there, with the NC in on the filament, the heat transfer is large, therfore you would need a high(er) voltage.

<small>[ May 21, 2002, 03:10 PM: Message edited by: xoo1246 ]</small>

[stanfield]

ok, so, what's the "recipe" for matcheads igniters ? could you give me the procedure ?

thanx !

huuum... the might be witout importance, but I usually use ping-pong balls for my laquer.

[mongo blongo]

It would be MUCH better to use NC grains!
As for the matcheads igniters, I never use this myself but you could crush the heads and add a small amount of water to make a slurry and coat the bridge wire with it and let it dry.
Anyone know the comp on rocket igniters by the way?

[Energy84]

Personally, I use double base smokeless powder mixed with acetone and coat all my ignitors with it.
The ignitors themselves are usually just wrap a strand of wire from some steel wool around a toothpick and solder some wire to each end. Then I coat the stick with my acetone/DBSP mix and let dry. They fire everytime with a 9V battery (just one of those little rectangular ones).

[stanfield]

What's your smokeless powder, and your ingredients ?

[Microtek]

I use a slightly different approach when using electrical ignition:

- A piece of cardboard is cut out in an appropriate size and a thin layer of glue is smeared on it. I use glue sticks for office use.

- A piece of Al kitchen foil is attached to the cardboard with the glue as smoothly as possible.

- Using a razor, sections of the foil is cut off, so as to form two leads and a thin bridge connecting the two.

- A small amount of highly spark sensitive material such as Ag2C2 or double salts is placed directly onto the bridge, and a small piece of adhesive tape is used to keep it in place.

- This ignitor is used to initiate the primary.

The current density needed will vary depending on the width of the bridge. Usually 1 mm bridge width will do for typical 6 volt batteries, but a standard 9 V battery will need impractically thin bridges to work. I use a capacitor discharge from a 400 V, 1000 mikro Farad capacitor. This makes the bridge explode with a quite loud crack, but unfortunately isn't enough for an EFI ( exploding foil initiator ).

[stanfield]

could I mix lead azide with a "glue" then put the filament in and let dry ? I think it will explode even if there is only a spark...

[mongo blongo]

From my experience Lead Azide doesn't work very well when mixed with binders or plasticizers. You would need more than a spark to set it off.

Edit- You could try mixing it with NC. I think maybe 20% NC could work.

<small>[ May 22, 2002, 08:33 AM: Message edited by: mongo blongo ]</small>

[stanfield]

what about the compatibility and the stability of the products ?

[xoo1246]

Remove

<small>[ December 11, 2002, 12:59 PM: Message edited by: xoo1246 ]</small>

[stanfield]

I maybe found the solution :
<a href="http://home.pacbell.net/sparksd/Pyrogen.htm" target="_blank">http://home.pacbell.net/sparksd/Pyrogen.htm</a>
but magnesium is very expensive... could it be replaced by an another product ? otherwise, is this "pyrogen" recipe reliable ?

Since I could buy 100g of magnesium for 15€, how many igniter could I make ?

The guy said to mix nitrate+magnesium with Nitrocelluloe laquer, ok, but how much ?

Could the potassium nitrate be substitued by sodium nitrate (which is cheaper for me...)

thanx for all !

<small>[ May 22, 2002, 12:29 PM: Message edited by: stanfield ]</small>

[Snipie]

I make my e-fuse from resistor wire and molten KNO3 and Sugar. They never failed me..

Solder 3 cm resistor wire (100 Ohm / M) between 2 wires (twist the resistor wire a bit around one wire). Then dip it in molten KNO3 and sugar. When it is dry, dip it in molten candle wax (I use pure paraffin) to make it water resistant.

The best way to melt the sugar and KNO3 is to take an old frying pan and put a metal pan inside, put the KNO3 and the sugar in it, let it stand (on 190 C) for 15 minutes, and voila molten sugar and KNO3.

I set my E-fuses of with a 12 V battery.

Some pics at: <a href="http://home.conceptsfa.nl/~sniper/EFuse/eFuse.html" target="_blank">E-Fuse</a>

<small>[ May 22, 2002, 02:08 PM: Message edited by: Snipie ]</small>

[xoo1246]

There is no need for any KNO3/Mg, you could use BP as well.
With some aluminum if you want it to burn hotter.
Snipie: how fast are your "E-fuses"?. I see two drawbacks:
Slow reaction time and requires high current. Am I wrong?

[stanfield]

I found a cheaper place for magnesium (250g for 22€)
so, is this pyrogen reliable ? anyone tested it before ?

thanx...

[PYRO500]

Thought I might mention that I have used a stub of fuse (NC laquor over BP coverd strings) with a pece of nichrome wire threaded through it. As for using a light bulb filament, I think they are too light and fragile to be of much use, Your ignition system should be able to take a litle pulling or else it's not reliable enough to have a safety advantage over fuse. I have messed with tiny silicon diode ignitors before, I ripped the idea from some kewl book, Apparently when you run about 12V through these things they will burn up regardless of their biasing. I would recomend purchasing a gel-cel backup battery (for ups's burglar alarms, emergency lights etc...) these can put out up to 4.5 amp hours (run for an hour at 4.5 A) witch is more than enough to heat a relitiely small diode into melting. I have to see if one of these actually will burn up a stub of fuse, I may try this soon and post results.

<small>[ May 22, 2002, 06:53 PM: Message edited by: PYRO500 ]</small>

[FragmentedSanity]

Slicone Diodes will work. But I still find they need a match head to produce enough heat.
IMO Nicrome is by far the best option for electrical igiters - that stuff will get damn hot before it burns the wire out - pretty much gauranteed to fire up - and its nice and strong too.
FS

[stanfield]

I love my igniter (when they work...) made with lamp filament because, when the nitrocellulose laquer is dry, it's very hard and protect the filament lamp from being broken ! it's hard like rock, so if you don't broke the filament during the manufacture, it's impossible to broke it after... really ! Last time when I made my 50 (wrong!) igniters, there is only 3 who didn't worked ! (I tested them with my multimeter) so, the "yield" :) is 94% of success !

after all, when these igniters are dry, they requires a few mA to work, so I can have a portable solution for detonating everything... (I attached them with the new Jumala's timer which work very well with a 9V battery (there are little and cubic)

So, I only have a problem of "ignitiating mixture" !

see ya !

<small>[ May 23, 2002, 02:11 PM: Message edited by: stanfield ]</small>

[Snipie]

The reaction time is (with 12 V) under the 0.3 second, it’s a bit hard to give an exact reaction time, but they are pretty damn fast.
And the needed amperage is not that high, because the resistor wire is very thin, so it can take maybe 0.2 W. And above the 0.2 W, it burns….

With 12 V and some resistor wire (3 Ohm) there will be a 4A current, that’s 48 W witch will be dissipated in the resistor wire….
4 A is a lot, but if your power source can’t deliver that kind of current, it doesn’t matter, because only 17mA is necessary to burn down the resistor wire (at 12 V).

I just tested it, and with 3 penlights (almost empty, 1.2 V each) it took 4 seconds to turn the wire (3.6 Ohm) red hot, the wire didn’t meld. With a 6 V battery (full) the wire melted instantaneously.

If you have some kind of electronics shop nearby, buy some 100 Ohm/M resistor wire, so you can see for your self (the stuff isn’t expensive, one dollar for 5 meter or so).

[stanfield]

I just tested out to crush match heads into powder but it's very very very long ! and the powder is full with piece of wood !
I will try to make 1 or 2 igniters with that...

see ya !

[xoo1246]

Hmm, you should only remove the matcheads, not the wood. <img border="0" title="" alt="[Wink]" src="wink.gif" />
How hard can it be? <img border="0" title="" alt="[Wink]" src="wink.gif" />

[stanfield]

how do you crush your match heads ? me, I take a knife then I "rub" the head...

[xoo1246]

Ok, I'll make a manual for you. :)
I'll post it here in a few minutes.
Edit: Lol, I feel really kewl, I have made an instructive image for removing matcheads.
<a href="http://w1.478.telia.com/~u47802930/stanfield.jpg" target="_blank">http://w1.478.telia.com/~u47802930/stanfield.jpg</a>

<small>[ May 24, 2002, 03:27 PM: Message edited by: xoo1246 ]</small>

[stanfield]

sorry Soldier F, I don't saw your message, yes I just tried to crush them with pliers and YES, this is very easy & effective ! I never had the idea to do it with pliers...

thanx for the tip !

[stanfield]

xoo1246, your link doesn't work, I tried to copy and paste it in a new window but it definitively doesn't work...

see ya !

[xoo1246]

Remove

<small>[ December 11, 2002, 12:50 PM: Message edited by: xoo1246 ]</small>

[PYRO500]

I remember a long while back when I tried making fuses the kurt saxon way, I took the thousand or so match heads and poured them into boiling water and dissolved the heads in the water leaving the match head fuel and oxidizer in solution witch I boilded down till it was a thick solution and dipped string in it. I am not sure how much of the actual fuel stays in even solution but I remember the little crystals of the stuff that formed on the sides of the metal tin I had burned pretty well. Now what if instead of dipping strings in this stuff you dip silicone diodes in this stuff ? I know that NC laquor will probobly work but it is probably not as cheap and readily avalable as this. also has anyone tried that match head idea with acetone instead of water (I hope you have the sense not to use an open flame) so you don't have to put up with that awful sulfur stench but you can smell that pleasent sweet acetone smell. :D

[stanfield]

my matches doen't dissolve in acetone in any proportion...
I will soon receive my 100g of sodium azide I ordered, do you think it could be possible to make powerful matches with lead azide (since it's extra sensitive) ?

bye

[nbk2000]

Perhaps it'd be possible to melt or dissolve off the plastic casing of a semiconductor to use it as a basis of a SCB (SemiConductor Bridge) initiator?

I too had some troubles with the NC laquer/SC/Sugar mix. Rather, I just used straight NC dusted with ground lighter flint powder. You make that by taking a used up lighter and SLOWLY turning the flint wheel to grind up the flint.

The powder gives a very hot flash of flame when the NC is ignited.

The SC/Sugar mix sprinkled on the NC didn't do much more than just fizzle a little. Probably because it wasn't microfine powder, but rather sugar granule sized, thus not finely mixed enough to properly combust.

[SATANIC]

i hate to admit it, but i have constructed working initiators from match head powder, ground with just water. (boiling water) then i coat it over small light globes.

Using a cheap set of christmas tree lights, i can make 45 for around $15 including all the materials...

[stanfield]

this is what I used but my mixture were shitty !
As a bloody, I made all my 50 mini lamp in one time and no one worked... shit !

[stanfield]

Do you think it could be possible to make a pyotechnic mixture with nitrocellulose lacquer then add the primary to this mix ?

thanx

[kingspaz]

stanfield i think this can be done with any primary so long as it isn't soluble in acetone. this method has been used to cast AP and HMTD into detonable blocks. it also decreases the friction sensitivity a bit as the NC holds the primary crystals in place so they cannot rub on each other and other things so easily.

[Mr Cool]

A good pyrogen would be a mixture of KClO3, charcoal and grains of something that burns hot. This could be Al, Mg, Si, SiC... even iron filings work.
KClO3/charcoal ignites very easily. Mixtures with sugar as the fuel take longer to ignite, because the sugar must heat up, melt, heat up a bit more and decompose before it ignites, whereas charcoal doesn't need to melt etc so it can catch fire more easily, from a smaller input of energy.
The KClO3/charcoal mixture burns hot, and ignites the grains of Mg or whatever. These then get flung into the primary, and continue to burn until it detonates.
A good filament is nichrome, bent around a small square bit of cardboard, so the wire goes up one side of the card and down the other. That way the card supports the filament, and prevents short circuits which could cause problems if they occur too near the ends of the nichrome.

Stanfield: I think 250g of Mg would be enough for about 1000 detonators if you used it carefully.
Hang on a minute... you're buying NaN3 and pentaerythritol from the SAME COMPANY???

[stanfield]

yes, from acros organics

thanx for your mixture but which ratio ?
Aren't KClO3 and Mg incompatible ?

see ya !

[stanfield]

I found, browsing the web, these ratio :

#1
KClO3 : 67%
Charcoal : 0%
Magnesium : 33%

#2
KClO3 : 75%
Charcoal : 15%
Magnesium : 10% (initially, it was sulfur...)

what's the best mixture ?
thanx !

<small>[ June 09, 2002, 03:37 PM: Message edited by: stanfield ]</small>

[Mr Cool]

Ratios aren't that important, just mix up a good, fast burning KClO3/C composition and then add about 15% Mg, Al, Fe or whatever you decide to use.
Both those mixtures you posted would work, but I think the one with charcoal will ignite more easily from a hot wire.

I still can't believe you're buying precursors for one of the most common military primaries and one of the most powerful common secondaries from the same place!! I wouldn't dare do that...

[stanfield]

I don't buy to Acros Organics directly but I have a reseller in France. I phoned them and I said I was a student in love for chemistry :) Each time I phone them to order, the women absolutely don't know anything to chemistry so I can buy all the acros organics catalog without be disturbed !

Otherwise, sodium azide, red phosporous, pentaerythritol, bis ethyl hexyl sebacate/adipate, mercury nitrate... are very hard to get ! Furthermore, Acros has the best prices on products I ever seen !

If pigs come to me I will said I'm an pyrotechnic amateur... this will calm them but in France, the "big brother" system isn't very effective ! there is no CIA or FBI here :)

see ya !

<small>[ June 11, 2002, 03:54 PM: Message edited by: stanfield ]</small>

[DeAd]

hey all, new member here, this is my first post. you all have listed off alot of good ideas(ive never tried them)but they sound plausiable.
what i use is camara flash bulbs there old to me but i didnt see any mention of them. i dont know if there available in all countries but heres a picture of them
<a href="http://members.aol.com/edwashere2/images/img00002.jpg" target="_blank">http://members.aol.com/edwashere2/images/img00002.jpg</a>
just the flash bulb
<a href="http://members.aol.com/edwashere2/images/img00005.jpg" target="_blank">http://members.aol.com/edwashere2/images/img00005.jpg</a>
the blue dot ones are guarenteed to flash,, best if you peel the plastic coating off before use. they work good for most things that a fuse or solar ignitor would work for and they can be found really cheap 12 for 25 cents (US)

---
Please pay more attention to proper spelling
---
ok Machiavelli i missed one letter in two words sorry for any problems this caused you. !tihs
---
Actually, there are a lot of spelling mistakes and punctuation errors, but there is no need to make too much of an issue over this -zaibatsu
---
Are you missing a period here ......^ ? Anyway this is starting bad. I suppose keep doing your lightbulb things, with their large power sources. I was just trying to help. For the person who started this thread try my idea and you'll be most happy with or without spelling errors.

<small>[ August 31, 2002, 01:58 AM: Message edited by: DeAd ]</small>

[NoltaiR]

I have always used regular 12v leads going to a few strands of steel wool embedded in a small charge of commercial BP or pyrodex. And always powered by a 12v lantern battery. Work everytime for me!

[Jumala]

Hallo Stanfield,
I had a lot off problems with my arcor mail accout last month wich I recognized very late. Perhaps I didn´t answere your emails.

Don´t waist the 50 lamps.
If you have a adjustable powersupply (0-30V) you can test at wich voltage and current the igniters work.
When it is not to high then you can modify the timer. At first it works up to 15 V. Then you can change the transistor. Use BC 639 because it can switch up to 1 A ( The BC 547 only 100mA)

So you can overload the lamp 3 or 4 times to get ignition.
The lamp wire will be only destroyed by heat but this happens not before ignition (impossible)

[stanfield]

even with the BC547, I never had 100mA, Now I'm using a big 6V lantern battery so I have no problem ! but this is too expensive so I will try to use two 9V in parallel... furthermore, I detonated a PETN detonator and this battery suffered due to a fragment !

I usually use 6.3V 40mA mini lamp but I ordered 4V 60mA, maybe they will work better ?

Secondly, I use a mixture of KCLO3, Carbon and Sulfur, and YES, it ignites better !

I'm always looking for a portable solution so an adjustable powersupply is impossible to transport in the forest where I usually "test" my explosive !

What software do you use to make your typo ? I'm looking for something easier than Cadsoft Eagle Layout 4.09

A good idea will be a timer wich, at the end of the programmed time, "suck" ALL the current of the battery in a very short time ! This doesn't matter because the timer and the battery are intended to serve only 1 time ! (depending on how much explosive you planted...)

sorry for my poor english !

[leonvios]

I know this is not about the same topic but cannot post new posts so I was wondering, how to make a radio detonator that could be reliable cheap and semi easy to make.

I was thinking of cheap walky talkys replacing one of the speakers with nicrome wire or brillo pad strands would this work or will I have to make it more technically than that?

Sorry if you don’t like my post but I could not find this in a search if you can tell me where this information is please.

<small>[ August 31, 2002, 12:39 PM: Message edited by: leonvios ]</small>

[xoo1246]

I know why you couldn't find anything, you should work on your spelling...
Anyways, replacing the speaker with a nicrome wire is not reliable and dangerous. This topic has been covered before, so I suggest you take a lexicon and try searching again.

[stanfield]

I've already posted a topic on this and both Jumala and me conclued that a cheap and easy-to-make solution is impossible for everyday use...

I made an electronic section on my web page where I scanned a book on radio transmitter, there are both emettor and receptor with schema, typo... only the components are missing ! :) when I'll have some times, I will post them !

[Jumala]

off coarse,- for single use a cheap battery is nessesary.

A good 9V Battery is able to give more than 1 A current. (for use in stuns) If you switch two batterys in parallel it has two bad and no good propertys.
1. you get not 1 mA more current because the voltage is already 9V
2. If one battery has a little higher voltage than the other, this battery will be discharged over the other battery.

The current through the lamp depends only on the voltage and the lamp-resistance with exception the transistor has a to high ON resistance.
This could cost some power.

The adjustable powersupply is only for find out the best ignition voltage for your lamp. (Without HE) This should be done at home.
You can take one lamp and increase the voltage until ignition occurs.
Then you read the voltage meter and add 2 or 3 Volts for safety.
This is the voltage the perfect battery should have.

If one 9V battery don´t work properly it will be the best to switch to batterys serial (18V). A additional Z-Diode and a resistor can regulate the voltage for the 4541 chip to 12 V.

Or much more simple,the transistor gets the 18 V and the timerchip only the 9V from between the serial batterys. This works good.

[stanfield]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">Or much more simple,the transistor gets the 18 V and the timerchip only the 9V from between the serial batterys. This works good </font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">==&gt; sorry, I didn't understood :) could you explain ?

oh ! and I'm using saline battery because, ofcourse, they are RELLY cheaper than alcaline ! (but I don't think it decreases the performances a lot...)

thanx for all !

[Anthony]

Using batteries in parrallel would allow more current to flow into a high wattage bulb. But we don't want high wattage bulbs, as the filament will still burn up in even the lowest power bulb and provide ignition.

Saline battery? I'm not sure what battery you mean, but I take it is a commercial, primary, dry cell? Alkaline batteries have better power output, zinc-carbon for example just plain sucks in high drain applications (like this).

I'd add quite a large safety margin in regards to ignition voltage. 100ft of blasting wire could eat up a lot of volts in bad conditions.

[stanfield]

yeah I'm using "saline" battery (dunno how to say in english !) because, here, alkaline are expensive !

Hey, Jumala, what about a "timered stun gun" ? could it be possible to make one ?

thanx !

[Jumala]

Hallo Stanfield,
I tryed to send you a email with the modified timer but the mail comes back twice.
Do you have a new email adress?

[stanfield]

damn ! I was at AOL first and I didn't modified my profile when changing my provider ! shame on me ! :)
I have this email which doesn't change : COMMANDE_SUIVIE@HOTMAIL.COM

sorry again !

[Flying Dutchman]

Stanfield,
You're from France right?
Then you shouldn't complain about costs of batteries!
there pretty cheap comparing to Holland.
As for the ignitor, I used the X-mas lights alot some years ago.
they were pretty cool!
just cut them open and put some BP in and you're done

-FD

[BrAiNFeVeR]

I use X-mas lights filled with BP too, but I place them in a straw (they should fit nicely).

So first I cut about 8 cm of a straw, jam the little lamp (broken open at the top) in the end, fill with some BP so the entire resistor wire is covered, and then I add my primary (AP or HMTD) the rest of the eight cm. Then I tap it softly to make sure all AP settles and leaves no holes, and then I softly press it.

It works wonders and initiate even pretty hard to detonate things if you turn about 75 cm of cotton wire around this, and soak 2 ml of NG in this :-p

Check out the vid on the bottom of <a href="http://www.geocities.com/brainfevert/index8.html" target="_blank">this</a> page if you want to see what such a detonator can do to an Al profile ...

[Marvin]

stanfield,
"Secondly, I use a mixture of KCLO3, Carbon and Sulfur, and YES, it ignites better !"
Dont make pyrotechnic mixtures containing chlorates and sulphur. They burn better but they are unpredictable in the long term. rec.pyro is fairly paranoid about chlorates in general and rather unfairly, but chlorates and sulphur mixtures are a really bad idea to be messing with. Do a search to find out why, or consult virtually any book on fireworks. I'm slightly surprised noone else pointed this out by now.

Since you are in france I assume you can buy neer pure sodium chlorate weedkiller, it makes it a good oxidiser for pyrotechnic/explosive mixtures but you need to be much more careful you arnt mixing incompatable chemicals together (I used sodium chlorate for several years with no problems). Since you are using KClO3 I'm assuming you can get KNO3, which you might want to think seriosly about using instead. Its much more tolerent to mistakes and you can make mixtures almost as impressive with proper processing. For something as simple as an ignitor, and something so potentially devistating if it goes off at the wrong time, you really shouldnt be using chlorates at all.

[stanfield]

whaou !... you frigntened me a lot...

I made 20 detonators with 1g of PETN in each ones... all the igniters are made of KClO3, C and Sulfur + nitrocellulose lacquer, they are ALL in the same box ! Do you imagine if one goes off ??? Serioulsy, they have been made 1 month ago, when will they explode ? How many time got I ?!?! Don't you think that the nitrocellulose lacquer will prevent the mix to be oxyded ?

thanx for all...

[kingspaz]

stanfield i would dispose of all those detonators immedietly. the reason for the instability is this:
ever seen what happens when you add KClO3 to H2SO4?
KClO3 + H2SO4 --&gt; HClO3 + KHSO4
2HClO3 ---&gt; H2O + ClO2 + ClO3 (not sure about this reaction but its bad :()
now, everything in the atmosphere is oxidised to some extent by the O2 in the air. S being non-metallic has acidic oxides therefore if sulphur contacts the air acids are formed to some extent from H2O and O2 in the air. there is only a very small amount formed. in the presence of KClO3 you have the very real possibility of HClO3 formation and thus the formation of oxides of chlorine which will oxidise the reducers in the primer (charcoal and sulphur, hey this means the process catalyses itself!!!...learn somthing new every day :) )
in light of this you definately should dispose of the caps this second! the longer you wait the more chance of an accident!
for a primer comp i use 75% KClO3, 20% charcoal and 5% dextrin. this mixture is put over the bridge wire when damp and left to dry. once it sets it forms solid rock protecting the bridge wire.

[stanfield]

damn, shit ! it tooks my hours to make these caps ! what's the procedure to defuse these cap ? they are sealed with epoxy resin (hard like rock !) DAMN DAMN DAMN !!!

So, if I understood correctly, the only problem in my composition is Sulfur ? I can always use KClO3 and Carbon but Sulfur must be avoided for long use ? ARGH ! life is hard !

thanx for the tip... you probably saved my life...

[kingspaz]

yes sulphur is the only problem with the comp. also you must make sure the PETN is thoroughly neutralised otherwise a similar result would occur:
H+ + KClO3 ---&gt; HClO3 + K+ (the H+ coming from the residual acid)
but if you remove the sulphur and make sure the PETN is neutralised then it should be fine.
to destroy them what i would do is put them in a hole then put a big thermite or KClO3/sugar composition on top (don't fill the hole in). light the fuse and run! make sure you have a big fuse though because you're going to be setting off 20 dets at once.
good luck and be very careful handling those caps.

<small>[ October 05, 2002, 05:46 PM: Message edited by: kingspaz ]</small>

[stanfield]

I was thinking on an underwater detonation... more funny, no ? how could I make my electronic timer "waterproof" ? with plastic bag ?

thanx again !

and yes, my PETN is VERY WELL washed, I tested it with a blue litmus paper and it stayed blue...

[kingspaz]

underwater could be tricky when trying to destroy a load of dangerous caps. you have to make sure they all go off and underwater you have to use an HE and therefore make another detonator...or use one of the dangerous ones. but on the surface in the open air you only need an incendary and its much easier to do.

[stanfield]

I though to detonate only one, the 19 anothers will too...

[stanfield]

I want to detonate them under a big rock (there's a little cavity...), what's the security (safety ?) range for me ? 20 meters ?

[SATANIC]

Well, I've got my own little ignitor problem.... (better not to start another topic right?)

I would usually use christmas tree lights, but I have used all those from last year, and they aren't in the shops for this season yet :(

I tried what I was sure was nichrome wire, (from toaster filaments) but no luck there (maybe because it was pretty well coated with crap, it was an old toaster)

I then purchased silicon diodes, and not knowing which to get, got both types availiable. (smaller "small signal" type and regular or something.

Neither of these were hot enough or produced any flame suitable for use..... First I tried each over a matchhead, and only the small one worked, and then only once in half a dozen tests. They all broke down, with a very small red heat across the centre wire, but not nearly enough to cause ignition.

I thought they were the most reliable for of ignition.... have I done something wrong, or is it just that they are'nt as good as people make out?

[stanfield]

By using nichrome wire, you must have high amperage to make the filament red...
But mini lamp are pretty common, no ? try looking in an electronic store/catalog :)

[Anthony]

You should be easily able to find christmas lights online. Or as suggested, by a load of little bulbs, although this might be more expensive.

Try some 1/8 watt, low value resistors instead of diodes, they don't go open circuit so quickly.

Two things with the toaster filament: a) make sure you have enough current to heat it, it's quite thick so will need more than a 9v ((3 battery. b) make sure it isn't too long! The length, and thus resistance, is matched to the mains voltage. If you're using a battery, the voltage won't be high enough. Try with a piece which is no more than an inch long and see what happens.

[SATANIC]

Thanks, I'm just going to wait till christmas displays start up, ( matter of weeks now) and get some cheap ones then, remembering to stock up this time, so I don't fall short of next christmas.

The toaster filament was pretty thick, and I was trying less than a centimetre, but only the one 9 V battery. I suppose I'll give the resistors a go, I now know silicon diodes aren't worth the trouble.

I don't shop online either, as I don't have a credit card, and it's too much of a hassle when I know most things are in a shop close by anyway.......

I'm happy just to wait a couple of weeks anyway, not like I have anything I want to set off urgently, so not really a hassle. I was hoping to find a better alternative in the meantime, but I'm happy to stay with the tried and tested.

[SATANIC]

I've just decided to continue testing, (however unnecessary), and have decided to try resistor wire.

I have the choice between 3 ohm / metre, and 6 ohm / metre. I assume I should use the 3 ohm because it will be easier to 'overload' creating the heat that I need right?

The 3 ohm 'cuprothal' (or something) is rated to 400⁰C and the 6 ohm is 'nichrome 80' and is rated to more than 1000⁰C.

Any reccomendations?

[Jumala]

I recommend also resistors. You get every resistance value you need for your available powersource. Simple calculate the value for maximum power supported by your powersource.

<img src="http://www.elexs.de/widerst.gif" alt=" - " />

The small resistors on the pic are perfect.
Try to get metallfilm types. They cost only a few cents and they can burn holes in epoxy boards.

[stanfield]

An another problem :
Yesterday, I finally detonated my 20 (dangerous) detonators.
Firstly I attached one of these "old" det to the jumala's timer and it didn't detonated, the timer worked well but apparently the detonator got a problem... So, I came back to home, re-made 5 detonator with sulfurless electronic igniter (70% KClO3 + 20% C + 5% Dextrin + water) and then, no problemo, I put this new blasting cap with the others and all worked perfectly ! I liked the sound but there wern't very high damage... I detonated them under a big rock, the rock wasn't damaged, only some earth was removed... not very important.

My question is : why the old BCap didn't worked ? the igniter is made with KClO3 which is an oxidant, do you think it's possible that KClO3 "attacked" the lamp filament ?

thanx !

[kingspaz]

it could be possible that a combination of KClO3 and sulphur caused corrosion of the filament. the unstable HClO3 formed in small amounts would readily oxidise the filament. thats only an idea though, the oxides of sulphur present could equally be to blame.

[stanfield]

ok...
and now ? there is only KClO3 and C, are my igniters long life stable ?

[kingspaz]

well, yes. if not thehn neither are mine :(. they should be fine now because they do not contain anything unstable or reactive towards metals. the KClO3 may possible oxidise the filament but this will be a much slower process than when sulphur was present.
i've got a similar ignitor i made a few months ago and i've tested it with a multimeter and its still live :) . if it'll last a few months it should last longer i'd say.

[stanfield]

maybe we should dip the filament in nail varnish before, it will protect it from oxydant. I don't think it could be a cause of failure...