Although not familiar with the Insulcast material, based on the nomenclature I guessing its an "Addition Curing Silicone". If this is the case there is a long list of "inhibitors" that will give you problems including: Latex, Neoprene, Buna W Rubber, Natural Rubber, Certain Tapes etc. For a more complete list go to the Emerson & Cuming web site and look under "technical tips". Bill C. -----Original Message----- From: Carl VanWormer [mailto:[log in to unmask]] Sent: Friday, July 06, 2001 9:41 AM To: [log in to unmask] Subject: [TN] Insulcast RTVS curing problem (caused by latex gloves) We are potting an automotive application using Insulcast RTVS 27 (thermally conductive potting compound) using room temperature curing. An autopsy of a failed unit showed areas of gooey (uncured?) compound around several components of the assembly. The gooey areas are up to 3mm deep, and will flow slightly with gravity . This particular assembly had been re-worked before (un-potted, fixed, then re-potted). The areas that were gooey were not the re-worked areas, but were areas where the old potting material had been removed. There has also been a similar gooey effect around a Nitrile gasket. The vendor suggests that latex gloves (worn during the handling/potting operations) can cause the platinum based catalyst to become ineffective. A different compound with a tin catalyst (about twice the cost) will eliminate the latex sensitivity. We have been told to eliminate the latex if we are going to stay with the existing compound. We have also been told that Nitrile can cause similar results, but by using higher temperature curing (oven), the potting compound should cure before the Nitrile can cause a problem. Has anyone else had similar experiences with this compound? How about any better solutions? Carl Van Wormer Cipher Systems 1815 NW 169th Place, Suite 5010 Beaverton, OR 97006 Phone (503)-617-7447 Fax (503)-617-6550 ------------------------------------------------------------------------ --------- 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 ------------------------------------------------------------------------ --------- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------