In a message dated 10/27/99 7:25:32 AM Central Standard Time, [log in to unmask] writes: > Hi TechNetters -- > > Anyone got any ideas/experience with cleaning (nondestructively!!) assembled > PWBs that were exposed to an electrical fire? The boards are covered with > soot and associated black gunk. They are conformal coated (urethane). TIA. > > Sheila Smith, Marconi AES Hi Sheila! Sorry for the late reply, and I don't know if this will do any good... I worked for a company that's no longer in existence, and experienced a fire. We worked a saturday and the operator who was running our aqueous cleaner (very old vintage), turned the pumps, blowers, and conveyer off when shutting down for the day, but forgot to turn the water heaters off. The equipment being as old as it was didn't have the safety components incorporated that later equipment has (like a complete power down if the temps in the wash water or rinse tanks exceeded a certain temperature), and proceeded to do a self-destruct...melt down if you will. Boiled all the water out of all the tanks and caught fire. Set off about 8 sprinkler-heads just above the cleaner, but there was smoke damage all over the production floor. Now this was back in the time when we all used freon to clean, and water soluble was the next big thing (doesn't seem that long ago does it?) But we ran all the finished/partially finished boards thru our Detrext freon cleaner, retested the ones that we actually were testing, and informed our customers of product we built that we didn't test of the problem that we had. Surprisingly, we only had to scrap a rack of boards that was close to the end of the cleaner that happened to get some melted poly on them (the cleaner was a poly- plastic constructed...old vintage, don't take that to mean that plastic cleaners are bad news). All the black-gunk cleaned off, but ours weren't conformal coated either, don't know that freon won't degrade the coating...also don't know that you can get freon anymore (without paying an arm and a leg...probably two arms and legs)... I feel for ya' Sheila, as Smokie the Bear says; "Only you can prevent Forest Fires..." which translates to any fire is no fun at all, no matter if it's inna a forest, or on a production floor... I know, I've been there... -Steve Gregory- ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################