Extra care must be taken to ensure that construction dirt, glazing lubricants or sealant volatile residues are not allowed to accumulate on the indoor surfaces of the glass within the shadow box cavity since they are difficult to remove and can stain the glass or the reflective coating.

Insulating Glass Spandrel

An insulating glass spandrel unit can be created by adding a clear glass lite with a dark colored frit on the #3 or #4 surface behind a reflective glass lite or glass of your choice. When used in an insulating unit, both lites must be heat treated. Annealed glass is not acceptable in spandrel areas because the thermal stresses normally encountered in an opaque cladding area could induce thermal breakage. Although this method is the most expensive, HGP recommends the insulating glass spandrel as the best construction for visual color match with vision glass on the building.

Ceramic Frit Opacification

Spandrel panels offer distinct aesthetic and economic benefits. Clear, tinted and pyrolitic reflective glass are coated with a durable colored ceramic frit enamel using a horizontal roller coating process. The pigmented ceramic frit enamel when it is fire fused onto the inside (#2) surface of the glass during the heat treating process produces an opaque colored glass panel. Ceramic frit coatings are available in a wide range of colors.

Fired ceramic enamel is durable and resists scratching, chipping peeling, fading and chemical attack. It provides a permanent finish, comprised ceramic frit and earthen-oxide colorants that inherent part of the base glass. Since the glass is to the exterior HGP spandrel panels provide durable, easily cleaned building panel.