Marcy PUGM4 Underglass Molding 7mm × 75ft | Firm Sponge | Windshield Installation

Underglass molding is placed along the pinch weld before the glass is set into the urethane bead. It provides a consistent resting surface that keeps the glass at the correct height and prevents it from sinking before the urethane cures. It also protects the glass edge from direct contact with the metal pinch weld.

Standard sponge (PUGM2, PUGM3) compresses readily — maximum conformity, best for uneven pinch welds. Solid (PUGM1, PUGM7) doesn't compress — a fixed, predictable height. Firm sponge (this product) splits the difference: it gives slightly under the glass weight for better seating than solid, but resists enough that the installer has more control over how high the glass sits than with a softer sponge. Many experienced technicians prefer firm sponge as a general-purpose underglass option.

A standard passenger vehicle windshield requires approximately 10–14 feet of underglass molding. A 75-foot roll covers 5–7 complete installations — enough for a week or more of steady windshield work for most technicians.

Yes — Marcy PUGM works with both urethane and ribbon sealer. Firm sponge is especially useful in urethane applications where some give is needed but the installer wants to maintain more predictable glass height than a soft sponge provides.

PUGM4 is 7mm firm sponge; PUGM5 is 6mm firm sponge. Both have the same resistance level and compression behavior — the only difference is the width. Choose PUGM4 for vehicles with mid-depth pinch welds (~7mm) and PUGM5 for slightly shallower pinch welds (~6mm).