A question was asked on rec.pyrotechnics about formulations for strobe comps that do not use dichromate. Here are some nitrate-based compositions.
#1 works particularly well, and by tuning the amount of 200-mesh vs. 60-mesh MgAl, it can speed the strobe up to a steady burn, or slow it to one or two flashes per second, with an occasional “stop”, followed by self-relight.
It’s not a true strobe in that it has more of a shimmering, intermittent burn than a regular on/off strobing effect.
This material works best simply “settled” in a 5/16″ i.d. thin paper tube (lance tube).
Adding up to 3% air float charcoal will make it less prone to go out, and easier to ignite.
Simply replacing the strontium nitrate with barium nitrate yields an acceptable green version.
Various Nitrate Red Strobes
|Magnalium, 60 mesh||9||9||6||12|
|Magnalium, 200 mesh||9||3||6||0|
#3 and #3b bound with acetone, but try/dextrin water.
I have used these formulations with good success and have even modified #1 with a little copper oxide and saran for a purple shimmering lance.
It should be pointed out that these are not products of my mind – I got them “off the web”. We should give credit to the anonymous original author.