`I know some people who build rocket motors commercially. They use a gaseous igniter to ignite their motor proper and spark ignite the igniter. It MUST always work. I'll copy them this thread and see if they are able and/or want to provide any free advice. Russell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .