Viracon, Dow Corning Update Customers on Sealant Concerns in IGUs
June 18, 2010

As a follow up to the notification sent by Viracon last week to customers that that they may have received insulating glass units using a problematic batch of sealant from the company's silicone supplier, Dow Corning (CLICK HERE for related article), Viracon today issued a notice to certain customers updating them on the matter.

The letter, which was sent by Viracon president Greg Silvestri, states that since last week's notice, "Viracon has worked closely with our supplier Dow Corning to investigate and identify suspect 982 base that may result in micro bubbles within the secondary seal of insulating glass units."

The letter continues, "We have been heavily engaged in identifying specific projects and customers with suspect IG units so we can work to ensure product safety and uphold our customer service commitment. We have inspected thousands of units within our inventory and in customer supply as recommended by Dow Corning, and along with Dow Corning's investigation and review, believe the scope of this issue has been substantially narrowed."

In addition, Viracon also says its investigation and testing "determined that IG units for installation into four-sided mechanically captured glazing systems need not be inspected for micro bubbles and may be installed."

Dow Corning provided USGNN.com™ with a statement, saying it has "conducted a comprehensive investigation and found this intermittent and isolated issue was likely caused by a failed seal in a drum off pump, but only when certain environmental and/or processing conditions were also present. The failed seal was immediately repaired upon discovery. Dow Corning has implemented engineering and process controls to prevent similar incidents in the future. The drum off process is dedicated to Dow Corning® 982 Silicone Insulating Glass Sealant base. No other products are affected due to this issue. Based on the investigation to date, the potentially affected sealant is only present in a small percentage of batches within the batch range 5944452 to 6010209. The time period for this batch range is limited to material manufactured between March 10, 2010 and May 3, 2010."

CLICK HERE to read the notice sent by Viracon.

CLICK HERE to read the statement from Dow Corning.

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