There are easier and safer options than zinc/sulphur.

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There was a pretty slick idea that Dr. Zooch did to create some neat smoke/fire for his Saturn IB/Milkstool setup...

He installed the regular desired rocket motor in the rocket, and then 'CHAD staged' a booster motor underneath it, which was then securely attached with three thumbscrews to a ring mounted to the base of the launcher. The ignitor was installed in the booster motor and fired in the normal manner as a two-stager would be.

The booster motor fires but is held to the pad, producing a large cloud of smoke, and at burnout ignites the sustainer motor in the rocket, which then takes off for it's flight like an ordinary single stage rocket.

Now two things immediately come to mind. First, this might bend or ding a safety rule or two and might get somebody's panties in a bunch at a club launch, so talk to your club RSO before you try it, if you're doing it at a club launch. Second is, this was using a "special" launcher, modeled after the Saturn IB "milkstool" used by NASA to allow Saturn IB flights for the Skylab/ASTP program from the existing Saturn V pads at Complex 39A/B instead of having to refurbish the mothballed pad at Complex 34 which saw all previous Saturn I/IB operations through Apollo 7. It was basically a tower extending from the existing Saturn V launch platform to the correct height for the Saturn IB stack, when placed atop it, to use the standard tower connections for the S-IVB stage and Apollo CSM connections/white room as it was set up for Saturn V... basically replace the S-IC and S-II stages of a Saturn V with a Saturn IB first stage and a tower to make up the height difference and you've got the setup. This raises the booster motor several inches above the blast deflector so that the flame never really strikes the deflector itself, which prevents it from melting. If you put a booster motor in close proximity to a standard blast deflector plate and prevent it from lifting off, so that the flame impinges on the blast deflector for the entire burn, it will likely burn a hole through the plate like a blowtorch through butter and either set the launcher afire or start a fire underneath it.

Another thing is, IF you choose to use a method like this, be sure you mount the booster motor in such a way that it CANNOT move-- IE don't just tape a booster motor to the launch rod with a standoff or something, as it will likely lift off with the launch rod and rocket and be completely unstable (sorta the reverse of the "stick stability" of a bottle rocket with the launch rod sticking up above the model and all the weight of the motors at the opposite end, and fins on the rocket itself far too small to overcome those destabilizing forces) and be EXCEEDINGLY dangerous, like an unstable powered jousting lance! (See Dr. Zooch's video archive of his first cold power static test launch with the rocket taped to the rod to see what I mean) Remember safety first and think through all the 'what will happen if's' before you try something like this...

That said I'm sure it can be done safely and would be infinitely safer than attempting a sulfur/zinc homemade smoke motor...

Seems like some fireworks type smoke bombs would work too...

Basically you need the formula for delay train powder-- slow burning, lotsa smoke, no thrust. Use that instead of regular BP for the 'thrust phase propellant' and you've got an FX motor...

Hope this helps! OL JR

BTW though they came in about the time I no longer had time or money for rocketry in my pre-BAR days, I always liked the FX motors and thought it was a NEAT idea, and always wanted to try it but never got around to it... JR

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