There are arange of other chemical reactions which liberate energy with minimal gaseous products. A competent pyrotechnic chemist should be able to advise. I'll post a modified version of the quesry on a rocketry list and see what responses we get. Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist