If the budget allows you can buy an ematch kit for about $1 per
igniter with 3' wires and have all the tricky soldering already done.
Typically use the chemicals provided as-is and have it ignite
additional pyrogen, thermite, etc.
https://electricmatch.com/pyrotechnics/see/8/5/nichrome-e-match-kit
https://www.apogeerockets.com/Rocket-Motors/Motor-Starters/E-match-Starter-Kit
On Wed, Jan 20, 2021 at 1:12 AM Dr Edward Jones <RocketPioneer@xxxxxxxxx> wrote:
Reinventing some wheels can be entertaining.
Ignition with a fresh Duracell alkaline 9vdc battery was a choice, for
this KNSB solid propellant application. Telco 18-g "bell wire" was
selected for the 12" lead wires. [I learned this is better known as
"annunciator (bell) wire".] Solid copper enables easier soldering to
Nichrome bridgewires. Nichrome was selected as the bridgewire of
choice, and 36g as the optimum size. That's so tiny it's almost
invisible. Maniplation requires care and dexterity, and/or an
Optivisor. It looks like chrome hair.
Nichrome isn't readily soldered, though Rubyfluid Soldering Paste with
60/40 rosin core solder permits rapid solid connections with the
nearly-invisible 36-g wire. I've found that a bridgewire of about
0.5-inch L will swiftly heat to orange-red with the Duracell, yet not
melt or burn thru. If that bridgewire is wrapped around the PVC
insulation of one bell wire strand, it becomes less fragile yet
well-exposed for pyrogen dip.
Smokeless powder dissolves in acetone readily, producing a NC dope
that's superior for dipping the bridgewired electric matches. Multiple
dips with short times to dry produces a resistant covering that's
flexible and at least water repellant. Any NC dope dip produces a
sticky surface ideal for dusting with any pyrogen: FFFFg Goex,
Pyrodex, Mg, Ti. Flame temperatures are more than adequate for dense
KNSB grains.
Realizing all this is well-known to experienced rocketeers, perhaps a
beginner will read this post and learn something.
Ad astra
Edward