Rudy's explanation is an elegant one, just one thing to add: It is possible depending on the original cause, that once you have started on the sequence described that it will continue. The formation of the carbonate releases the original acidic component which will take more material to a soluble salt which gets more CO2 to make a carbonate which .... and so on. This explains the sometimes relatively large amount of these deposits compared to the initial amount of "starter." Mike ----- Original Message ----- From: "<Rudy Sedlak>" <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, January 31, 2001 2:51 PM Subject: Re: [TN] Lead carbonate growth during humdity testing > Lead Carbonate formation is almost certainly a two step process. > > The first step is probably formation of Lead oxide, or other Lead salt, > probably done at high temperature, and/or aided by some chemical that is more > aggressive than Carbonate, like Chloride. > > The second step is the reaction of this Lead salt, with either your > Armaclean, or atmospheric Carbon Dioxide, to give you Lead Carbonate. > > Not sure how much this helps, but this is an analysis knowing the chemical > properties. > > Rudy Sedlak > RD Chemical Company > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------