Author |
Message |
Robin E. Snyder Senior Member Username: robin
Post Number: 55 Registered: 08-2004
| Posted on Wednesday, July 05, 2006 - 10:24 am: | |
A glazing consultant has recommended that we heat soak our tempered glass to test for inclusions. Is this common procedure? Can anyone explain to me how this works and if there are any other options? |
Richard Howard, AIA CSI CCS Senior Member Username: rick_howard
Post Number: 85 Registered: 07-2003
| Posted on Wednesday, July 05, 2006 - 10:42 am: | |
Viracon has an explanation of heat soak testing in a TechTalk on their website. http://www.viracon.com/viraconsultingWhitePapers.php |
Anne Whitacre, FCSI CCS Senior Member Username: awhitacre
Post Number: 358 Registered: 07-2002
| Posted on Wednesday, July 05, 2006 - 03:57 pm: | |
Robin: I require all glass on our projects to be heat-soaked. I've had only one squawk about that in the past several years, which leads me to believe that having that requirement isn't that difficult to comply with. (adding that was recommended to me by a glazier, by the way) |
Tracy Van Niel Senior Member Username: tracy_van_niel
Post Number: 180 Registered: 04-2002
| Posted on Thursday, July 06, 2006 - 02:24 pm: | |
We had a project many years ago that had spontaneous glass breakage with a final conclusion that it was happening because of the nickel inclusions. Viracon's recommendation, which we have adopted, is to require glass to be heat strengthened as a base, with fully tempered only where necessary to meet building code requirements. We also include the requirements for heat soak testing in our specifications and about the only people that have questioned it are some of the developers we've worked with. |
Ian Patlin (Unregistered Guest)
Unregistered guest
| Posted on Saturday, July 08, 2006 - 10:55 pm: | |
Robin - Heat soak is a common procedure to limit the possibility of a nickel sulfide reactions. It is always a part of any glass wall system we design. |
Ronald L. Geren, RA, CSI, CCS, CCCA, MAI Senior Member Username: specman
Post Number: 321 Registered: 03-2003
| Posted on Friday, September 01, 2006 - 12:01 pm: | |
Based on this discussion and a specific incident I know of, I'm now requiring heat soak testing in my glazing section. However, on a project we currently have out for bid, I'm getting getting some resistance from a glazing installer saying it'll cost "thousands of dollars" and the only manufacturer that will do it is Viracon. Does anybody know of what the relative cost increase would be, and if there are any known glass manufacturers that WILL heat soak test their glass? |
Vivian Volz, RA, CSI, CCS Senior Member Username: vivianvolz
Post Number: 80 Registered: 06-2004
| Posted on Friday, September 01, 2006 - 04:26 pm: | |
Saint Gobain will heat soak. |
Tracy Van Niel Senior Member Username: tracy_van_niel
Post Number: 190 Registered: 04-2002
| Posted on Tuesday, October 17, 2006 - 03:33 pm: | |
Just as an fyi, the October 2006 issue of "Glass Magazine" has a multi-page article on glass breakage from nickel sulfide inclusions. The article is based on a presentation given in Finland so includes reference to European standards and terminology (refer to tempered glass as "toughened" glass for example). |
Max Perilstein (Unregistered Guest)
Unregistered guest
| Posted on Tuesday, October 17, 2006 - 05:41 pm: | |
Some insight from the glass fabricator side... I will tell you that the reason no one (or a very rare few) heat soaks domestically is because the "inclusion" issue is so rare. The average spontaneous breakage used to be 8 per thousand, I believe it is significantly less now. Also, at least according to Pilkington and the other primary mfg's Nickel sulfide is more prevelant in glass that is made overseas. (though not sure if I believe that angle actually) Regardless this issue is not a big one from the domestic side. In the last 4+ years I can count on one hand how many lites we've had spontaneous explode in the field- and we have the 2nd most tempering facilities in North America. Plus as the folks that do Heat Soak like Prelco even note on their Heat Soak requirements that heat soaking does not guarantee the glass won't spontaneously explode. That too was a reason we stayed away from that technology when we realized we probably could have the same events whether we heat soaked or not. I know this may not be what you want to hear, and the angle of heat soaking may be what everyone wants, but I just wanted to give you some insight on why its so impossible to find anyone willing to step up and do it. Thanks for your time- Max Perilstein [Max is with Arch Aluminum - Colin] |