36 replies to this topic

[Arthur Brown]

Not all fluxes work for Nichrome, Cooperman's selection obviously does for him ( have you a trade name please? ) Bakers fluid is a highly regarded liquid flux for soldering which also works when soldering nichrome to copper. ( http://www.knighton-...id.html#a070342 ) is only one of several suppliers in the UK.

[StephF]

Not all fluxes work for Nichrome, Cooperman's selection obviously does for him ( have you a trade name please? ) Bakers fluid is a highly regarded liquid flux for soldering which also works when soldering nichrome to copper. ( http://www.knighton-...id.html#a070342 ) is only one of several suppliers in the UK.

I've ordered a small amount to test and I'll get back to you all with my results.

[StephF]

I also found this on Youtube, it seems ideal for this thread.



It seems to be almost identical to Cooperman's method although no disrespect intended Phil, the camera work is better

Ouch ! I bet that will come back and bite me in the butt.

[phildunford]

I also found this on Youtube, it seems ideal for this thread.

This sort of method will work fine if you are using a high current supply of reasonable voltage - this guy is using a lead-acid battery. It does depend a lot on the size of the fine wire and this will vary greatly depending on the 'flex' you use. It's easy to solder as it's copper.

If you want something a bit more sensitive you will need to use nichrome, you them have the soldering problem... Of course Phil C's method uses a wire-wrap technique and so does not need solder.

I now use 50 guage prepared match 'chips' (from the states at about 8p each) and just solder on the lead wires and dip in pyrogen. So far 100% reliable and they pop with a single aaa battery on 100 yards of wire...

[Arthur Brown]

Remember that a commercial pyro igniter has a resistance of about 1.5 ohms and most of this is the bridgewire! This typically means the wire must be very thin and of a high resistivity Nichrome is the popular choice, and there are very few suppliers of 50SWG nichrome (and very few people who can work with it without specs!)

A commercial ig fires at a current of about half an amp for 20milliseconds -well within the capability of a small battery, even at the end of a sensible shooting wire.

[portfire]

Well, with me having plenty of time on my hands at the moment, I tried my hands at making E-matches. The problem for me is I didn't want use my NC and not wanting to use exotic Pyrogen's

The story starts with my car not liking the rain (As paul knows) so I bought some automotive spray that you use on the ignition system and covers it in a waterproof layer. So yesterday had the idea of using Phil C's method (I used 38-GA Nichrome) then using the spray to protect from water. The end of the wire was then dipped in a thick BP slurry, and left to dry in the sun.

Using my 1-cue firing box and a car battery, I had instant ignition Soooooo today I've made 20 for further testing, one of which will be to see if this spray works (I'll report back on that in a few weeks).

Here's a pic
http://www.pyrobin.c...es/pic_0136.jpg

The length of each match is 190mm and I'm getting around 2.5 ohms on each one........You'll have to spoonfeed on this as to what I need with regards to continuity testing on a 12v system (car battery)

I'll post a vid tomorrow

Edited by portfire, 14 June 2009 - 08:28 PM.

[portfire]

Quick update. Almost 2 months and my BP E-matches are still firing