The Thermite like reaction is because the oxides bound in the materials of the battery form a redux reaction in which they reduce from one material (caused by heat) and bind with other ones causing greater heat this proces is self sustained, exotherm, and needs no Oxigen. Any CO2 would be ineffective unless you could cool the whole thing with liquid co2. Peter van Hoof ----- Original Message ---- From: R. I. Nelson To: Microcontroller discussion list - Public. Sent: Friday, January 06, 2006 9:03:31 PM Subject: [OT]low cost fire suppresion system WAS [EE] stupid (learning) mistakes William Chops Westfield wrote: >> <>The usual failure mode involves fumes and (rather violent) fire, >> rather than explosion and shrapnel. I would worry that your >> plexiglas would make a fine fuel for expanding the fire... >> A gentleman I knew had several lasers for cutting intricate designs in paper and wood. On rare occasions they would have a fire in the cabinet. I made a circuit for him that when the operator would hit a panic button it would turn off the laser, flood the cabinet with CO2 and slow the exhaust fan down quite a bit. He had CO2 on hand for some of the lasers. the exhaust fan was slowed down so it did not suck the CO2 out faster the we put it in and yet exhausted the fumes from the cabinet. You could add a system like this to your Plexiglas box quite reasonably. Get your self a CO2 bottle for about $20 to $50 dollars. a valve to fit bottle for about $10 a regulator for $30 to $40(this will drop the CO2 bottle from 900 + PSI to under 100 PSI. You can have the CO2 bottle filled at the local Paintball store for About $2 to $6 depending on size and location. You watch ebay you can buy the stuff at quite a savings. I have some of the used stuff on hand now if you wish to contact me off list. -----Inline Attachment Follows----- begin:vcard fn:Robert I. Nelson n:Nelson;Robert I. org:RIN Designs adr:;;P.O. BOX 373;RIPON;WI;54971;USA email;internet:rindesigns@charter.net tel;work:1-(920)-229-7152 tel;home:1-(920)-748-7443 note;quoted-printable:Custom design and building of small electro mechanical devices.=0D=0A= AUTOCAD work ver2002 x-mozilla-html:FALSE version:2.1 end:vcard -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist