Doug Answering your questions: 1 No 2 No 3 No Hope this helps!? Regards, Graham Naisbitt [log in to unmask] www.concoat.co.uk Concoat Limited www.concoat.co.uk <http://www.concoat.co.uk> Alasan House, Albany Park CAMBERLEY GU16 7PH UK Phone: +44 (0)1276 691100 Fax: +44 (0)1276 691227 Mobile: +44 (0)79 6858 2121 -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Douglas Pauls Sent: Tuesday, April 03, 2001 03:33 To: [log in to unmask] Subject: [TN] Acrylics and Silicones Good morning, Seems to be a morning for coating related questions. Like many high-performance manufacturers, we use silicone RTV materials around high mass components, such as them big honkin' electrolytics, to give vibration resistance. Our coating specifications has us coat over the RTV materials with acrylic coating (Humiseal 1B31). Our normal product acceptance screen is a thermal cycle of -55C to +125C. You can guess some of the adhesion related problems we have from the differential expansion rates and from the problems of trying to get anything to stick to silicones, as well as to the halo region around the cured silicones. Here are my questions: 1. Do you coat over silicone RTVs? 2. If you do, do you preclean the silicone and surrounding areas? If so, with what? 3. If you coat over silicones, do you use a primer material to promote adhesion? I imagine that this will be a dragon that I joust with regularly over this coming year, till I slay the beast (Mountain Dew starting to kick in folks). Tis an unwholesome creature............ Doug Pauls Rockwell Collins ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------------