pcm81 Posted April 4, 2015 Share Posted April 4, 2015 (edited) Tried 32 AWG nichrome wire yesterday. It is able to set off fine grit (400 grit) thermite directly from a 9V battery, however 425 grit magnesium makes it easier. Trick is not to use too long of a wire; i fount 2-3 inches is about the limit for 9V battery. You want to take long copper wire, attach 1"-2" length of nichrome to copper leads and put 9V through it. Nichrome will glow red and melt setting off thermite in the process.. 32AWG nichrome runs like $5 for 100ft spool on amazon. Naturally works for setting off all other pyro with ignition temp of less than 1100C. Edited April 4, 2015 by pcm81 Link to comment Share on other sites More sharing options...
deer Posted April 19, 2015 Share Posted April 19, 2015 I assume this is with a powerful battery pack, right? Because I find it difficult to get just 2..3mm of AWG 32 even to glow from NiMH (1.5V though). AWG32 wire is ~36 Ohm/m, 1" NiCr should be 0.889 Ohm's (more as the temp. rises). This means 10.123 Amp's to start heating the wire and should produce ~91.11W of heat. I think the 6F22/6LR61 battery can't deliver much more than few hundred miliAmps. My experience with cutting styrofoam is that from PC ATX PSU it burns paper at 5V but has no visible glow and glows brightly orange at 12V with ~4inch wire. Haven't measured current though, but the ATX is capable of 15..20A. So to conclude, what type of 9V battery? Link to comment Share on other sites More sharing options...
Arthur Posted April 19, 2015 Share Posted April 19, 2015 The aim with electric ignition is to fire from a safe distance. SO most commercial igs use wire about 50swg these fire at 500ma and you can fire them down a 100m coil of wire which is usually far/safe enough. Using fatter wire makes them harder to fire down a long wire. Link to comment Share on other sites More sharing options...
deer Posted April 19, 2015 Share Posted April 19, 2015 For even safer distances and better firing you could keep the battery close to igniter and just run relay switching wire. Simple relay costs much less than tens or hundreds of meters of high current wire. Even better - remote it and go wherever feels safe, not where you can pull the wire to.http://pic.o-o.lv/image.php?di=PL4T Link to comment Share on other sites More sharing options...
THEONE Posted April 27, 2015 Share Posted April 27, 2015 (edited) If a thicker nichrome wire can ignite thermite, i guess a thinner nichrome wire with more turns (making it thicker) it will be the same. I will try it. Edited April 27, 2015 by THEONE Link to comment Share on other sites More sharing options...
Nessalco Posted April 27, 2015 Share Posted April 27, 2015 Be careful with relays - the thump from lifting shells can bounce the contacts on mechanical relays and cause unintended firing. Kevin 1 Link to comment Share on other sites More sharing options...
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