The usual response is to keep the batches of home made powder small so even if they go off, the damage is limited.
......yep, and since we're talking "cannon grade" BP here, I think 10 pounds is a small batch.
Great post - Ulrich's page is terrific!
I read a recent post on the average price of buying BP (by mail order). At around $10.00 a pound, one imagines the topic of safely making very good to excellent quality BP at home, using inexpensive methods, has been brought up before. I don't believe I saw any links on it in a FAQ, though; maybe I missed it?
As an admitted, long-time (pyro (and member of the the Western Pyrotechnic Ass'n,
http://www.westernpyro.org/), I thought I'd post this great link to a few pages, authored by safe and sane pyrotechnicians, who explored several different methods of making BP at home using very inexpensive tools and supplies. They used commercial, and homemade charcoal -- and included a section on testing their batches showing the power/quality of commercial BP vs. homemade pine charcoal vs. commercial charcoal mixtures (surprise! Homemade pine charcoal kicked butt!)
http://blog.skylighter.com/fireworks/2008/09/making-testing-high-powered-black-powder.html They include one method (coating rice hulls) which is geared specific to making "lift charges" for fireworks shells - you can fast-forward thru that part...
regards,
wolff