It was also before the BATFE stuck their noses into things and put thermalite on their list.

__________________
I love sanding.

+1 to what tbzep said above.
Nuisance regulation.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

Luckily, I had bought a big roll from FSI back in 1990. I still ahve a little bit of it left.

I got rid of the last of my thermalite out of an abundance of caution.

In any case, the stuff goes bad with time. "The fire goes out of it," as one of of my old club put it.

Back in the day we used it for "air starts," staging (always a little dicey) and plain old motor ignition.

I did find and use an inch of it last year; an old FSI igniter!

I suppose an alternative would be a special staging igniter. A fast-burning fuse with a wide base to catch the flaming particles from the booster, and a really hot-burning tip, to get composite fuel burning.

__________________
NAR #27085 - Oregon Rocketry - SAM

A trick that is commonly used by European space modelers (especially for staging scale models, or old-rules Altitude competition models, with long first stage airframes) should provide reliable ignition of Q-Jet motors used in upper stages. It is a "blast tube," a thin-walled fiberglass "funnel" (which fits inside the upper end of the first stage [and "intermediate," if any] motor or motors), whose neck is long enough to fit up into the upper stage motor's nozzle (or nearly so). A pinch or two of black powder, placed inside the "funnel," jets enough flame forward/upward into the Q-Jet motor's nozzle to ignite its propellant. One or two of Stuart Lodge's books (see: https://www.google.com/search?sxsrf...HTLRCZ8Q4dUDCA0 ) covers/cover this device and how it is used.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

That is interesting enough I will have to give it a try in the spring 2021. I had never heard about this technique. Now that I am done with getting started on my latest hobby. Coop and run all built and the girls are in production.......

A variation on that marries the "blast tube" and "flashpan" ignition for cluster ignition. It's often called spider ignition.

Here is an article and photos about it.
http://meatballrocketry.com/pvc-spider/




.

__________________
I love sanding.

The "blast tubes" may also be "off-the-shelf" products.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

The European flash tube method is somewhat different from what you suggest. The European booster motors, unlike Estes booster motors, are not simply open propellant at the upper end. Instead, they have a small paper diaphragm with a tiny hole in the middle. A small amount of loose black powder is sprinkled onto the diaphragm to create a flame source to propagate up the flash tube. The lower end of the tube sits into the upper end of the booster motor. The upper end of the flash tube does not insert into the sustainer motor. Instead, it rests just below the sustainer nozzle with a small air gap. This serves the same function as the vent holes in U.S. style gap staging. I only know of one contestant who uses a flash tube with Estes booster motors and I seriously doubt such an arrangement would add any benefit to trying to ignite Q-jet sustainer motors.

The European (especially Central & Eastern European, including Russian) model rocket motors vary a lot in construction and internal arrangement, and there are many different manufacturers; Stuart Lodge has one of the largest--if not THE largest--collection of them. The FAI (non-scale) Altitude event rules, which favored "long first stage/small second stage" competition models, were changed some years ago, and this made blast tubes less necessary and common (the FAI Scale Altitude rules were similar, and made Bumper-WAC Corporal entries 'too common'). But a blast tube would help ignite Quest Q-Jet upper stage motors, by directing a jet of flame along the upper stage motor's propellant grain (the tube could have vent holes).

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR