Sciencemadness Discussion Board

Electric initiator

Petn1933 - 27-9-2019 at 04:14

Hello
I want to know from your experience what kind of wire you are using in head of electric initiator to create heat?

I use 3v lamp element

Tnx

johnmay - 27-9-2019 at 05:53

Hello there,

Personally I use short fragments of metal scourer (the thing that you use to clean after the dinner if you are lame at cooking :D )

I cut it in about 2 cm pieces and twist between the two wires.
It goes red hot even when using regular AA batteries.

Best regards!

underground - 27-9-2019 at 06:00

I personally use Nichrome wire, 40 AWG.

Praxichys - 27-9-2019 at 06:34

I used to clip the tips off christmas lights. These days, it's easier just to buy electric matches for fireworks from eBay. They're only around 20 cents each if you buy a pack of 100 and it saves a lot of time and effort, and they're far more reliable, especially if you gang 2 or 3 together for redundancy.

https://www.ebay.com/itm/100pcs-lot-11-81in-Fireworks-Wire-F...

Petn1933 - 27-9-2019 at 06:48

Thanks for all your comments
All of this are great
Steel wool and nichrome wire are inexpensive
Online E matches more reliable
i will test them !

[Edited on 27-9-2019 by Petn1933]

Vomaturge - 27-9-2019 at 21:24

Quote: Originally posted by Praxichys  
I used to clip the tips off christmas lights.



I've ignited a ground up match head with a christmas light. I wasn't trying light anything else with it, though. Sometimes, we do things just to see if it's possible. The beauty of it is that the filament can light without much power. The sad part is that if you poke a whole match, or a fuse, or any number of other things in, you will break it and have a dud.

For an experiment with lighting candles and toothpicks in closed container, I used a twist tie which was maybe .5 mm thick. In order to get it to melt and ignite flames instead of just charring the fuel, I used a 50A 12V car jump starter and fed it with 2ft 16AWG copper wires. If you're trying to electrically ignite something which won't light easily and won't be too violent (so you don't damage the jump starter), I think this method is hard to beat.

Random thought 1: I should try that experiment again, with some minor changes. Last time, I never figured out what steady state burning of a candle would look like at 7x atmospheric pressure.

Random thought 2: a Yablochkov candle just might make a nice ignitor for a stubborn reaction like thermite. Just saying...

[Edited on 28-9-2019 by Vomaturge]

wg48temp9 - 28-9-2019 at 01:19

Quote: Originally posted by Vomaturge  

Random thought 2: a Yablochkov candle just might make a nice ignitor for a stubborn reaction like thermite. Just saying...


My thought is such a candle could be used in an arc furnace so that the need to adjust the carbon rods as they burn away would not be needed.
For example in making CS2, P or Na. Perhaps with the calcium sulphate replaced with a different material more compatible with the intended reaction.

XeonTheMGPony - 28-9-2019 at 07:29

I use Nichrome doped with lead styphnate and Nitro cellulose.

Going to make a spot welding rig for welding the bridge wire, I have all so used steel wool strands soldered on, but much more delicate to apply doping mixture to some times.

underground - 28-9-2019 at 11:58

Quote: Originally posted by XeonTheMGPony  
I use Nichrome doped with lead styphnate and Nitro cellulose.


Does it go bang just like that ? Could a SADA work as a replacement of LS ?

XeonTheMGPony - 28-9-2019 at 15:34

it fires with a very solid crack

My preferred doping method is to have a thin gel, dip assembly in that, then dust with priming agent, then dip in a thicker gel to coat the priming compound. this protects every thing from moisture, air, movement. Makes for a very sturdy and reliable E-match.

NL dip 3.jpg - 366kB Primed wire.jpg - 309kB 1.5ohm bridge wire.jpg - 255kB

[Edited on 28-9-2019 by XeonTheMGPony]

underground - 28-9-2019 at 16:01

Very clever idea thanks. I have never considered an e-mach detonator. I bet SADA will work too

XeonTheMGPony - 28-9-2019 at 20:23

I was never a fan of fuses for the most part, so all ways preferred electrical, so much more reliable and safer.

20190928_220107.jpg - 85kB20190928_215741.jpg - 104kB

dave321 - 29-9-2019 at 08:26

Quote: Originally posted by XeonTheMGPony  
I use Nichrome doped with lead styphnate and Nitro cellulose.

Going to make a spot welding rig for welding the bridge wire, I have all so used steel wool strands soldered on, but much more delicate to apply doping mixture to some times.



be interested if you get your welding rig sorted, please provide details when ready

[Edited on 29-9-2019 by dave321]

Estes rockets

sodium_stearate - 29-9-2019 at 10:30

When I was a kid I had Estes model rockets.
At one time most hobby stores sold lengths of nichrome
wire to be used as electric heaters to start the Estes
rocket engines.

As I recall, it was probably about #30 Ga. wire.

You'd cut a short length of it, maybe 1.5 inches long,
then wind it in a few turns around the sharp end of a pencil
lead. That would leave a little coil with leads sticking out
from both ends.

You'd then push this tiny coil up into the rocket engine
nozzle, and secure it in there by pushing a small piece
of wadded up kleenex or tissue paper in behind it.

The two short wire leads then were attached via two
small clips to the launch circuit, which was nothing more
than a plain 6 volt lantern battery and a push button
on a long 2 conductor lamp cord.

After a few years all the hobby stores discontinued the
sale of the nichrome wire. Estes instead started manufacturing
special little assemblies that had the pre-made little
coil, but it was coated with some compound resembling
that of a match head. Those worked too.

MineMan - 29-9-2019 at 11:18

Buy the firework ones on eBay. Nothing worse than a dud. Especially when it’s not just the cap.