Dual Seal – Silicone/PIB IG Units

Perhaps the Insulated Glass, “IG” That has the greatest longevity in the window manufacturing industry is the Dual Seal – Silicone/PIB unit. The PIB forms the most effective seal against moisture and the silicone has structurally the strongest and most resilient of sealant bonds. Most often glass fabricators provide an irregularly applied 1/2” sealant band or sightline.

Through consistent, careful craftsmanship and use of the highest quality of materials, Green Mountain Insulated Glass is able to consistently provide as small a sightline as 5/16” on small lite IG units (2 1/2 square foot or less). Any millwork company that has ever attempted to blend a modern, energy efficient window with the look of period architecture is well aware of the need to keep the muntins (glass dividing bars within a given sash) as narrow as possible. Green Mountain Insulated Glass, Inc.’s accurate and reliable sightlines have regularly made the option of narrower muntins possible for many of its millwork customers.

Another important connection which Green Mountain Insulated Glass, Inc. has with the Historic Window Market is that we offer many different Restoration glasses to our customers in both monolithic and insulated modes. Green Mountain Insulated Glass, Inc. stocks many kinds of “cylinder” or “mouth blown”, “bull’s eyes”, and “rolled” glasses that are manufactured in the same manner as they were many, many years ago. These glasses can almost always be fabricated as Dual Seal – Silicone/PIB IG units where other systems are simply not as reliable to use.

And yet another helpful point is that of using historic glazing putty on Dual Seal – Silicone/PIB units. Some of our customers have had a very good experience with putty glazing on top of these IG units. Because some glazing putties may emit solvents during the putty curing process, (These solvents may be incompatible with the IG seals.), this type of glazing requires thorough, careful sealing of the IG unit into the glazing cavity. A prudent installer should also assemble and test a unit with intended glazing putties.