What was found
SELECTED WINDSHIELD DEFOG CLIMBING FL200, 45 MIN LATER LEVEL CRUISE FL400 F/O NOTICED RT WINDSHIELD APPEARED TO HAVE BUBBLE FORMING I/B HEATING BUS BAR, SURFACE HOT TO TOUCH. W/S DEFOG SYS SELECTED OFF. W/S DEFOG ANNUNCIATOR HAD NOT ILLUMINATED AFTER INITIAL UNDER TEMP INDICATION EXTINGUISHED. NORMAL OPS OF ANNUNCIATOR IS ILLUMINATION WHEN W/S DEFOG SELECTED TO OPERATE, W/S IS EITHER UNDER 85 DEG OR OVER 150 DEG. CONSULTED AFM & MEL, SECURED RT W/S DEFOG CIRCUIT BREAKER & USED W/S ANTI-ICE SYS TO PREVENT FOGGING ON DESCENT. MELTING OF HEATED PLY, SMALL AREAS OF DELAMINATION, SURFACE DEFORMATION ON INNER & OUTER PLIES. DAMAGE BEYOND LIMITS. W/S REMOVED & REPLACED. W/S DEFOG ELECTRICAL SYS BEING TESTED.