> From: pauljsmi...@cs.com > Sent: Friday, April 25, 2003 8:53 AM > > In a message dated 4/23/03 5:37:13 PM Eastern > Daylight Time, peter.tar...@sanmina-sci.com writes: > > > Bill - > > > If you're referring to what I think you are, it's > > "fuller's > > earth and waterglass," which is a clay-like mineral and > > sodium silicate solution. > > A former agency engineer I worked with also used > this waterglass adhesive for thermocouples. It > worked great and was usually easy to remove > thermocouples without damaging.
How well the waterglass adhesive removes from the thermocouples must depend on the percentages of each constituent in the admixture and the amount of water used to make the sodium silicate solution. I've had it turn to stone. Probably greater amounts of fuller's earth will aid in making it more crumbly and greater amounts of water (to a limit) will allow the admixture to also be softer. Fuller's earth and water glass takes a long time to dry and makes thermocoupling a more tedious activity than is necessary. In using cyanoacrylates, I've noticed that the accelerant makes the adhesive more brittle than setting in air would. Two more advantages of using the smallest possible amount is that, when you're done, the thermocouple can be removed from the part by placing a sharp blade at the margin and prying it up (or cracking it away) from the sensed part *and* the residue on the thermocouple can be broken off by gently applying pressure (working from the outside-in) with a pair of needle nose pliers (one with checkering on the jaws). The residue literally cracks off and more times than not, leaves a good bead intact. Regards, Peter L. Tarver, PE Product Safety Manager Sanmina-SCI Homologation Services San Jose, CA peter.tar...@sanmina-sci.com This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
