"V" or clean out the cracks, then fill with PC-7. An old hacksaw blade, hand administered will work well to enlarge the cracks enough to permit filling. Leave the fill slightly high and sand down to contour. The PC-7 will shrink very slightly while curing so be sure to leave it a bit high. I used a wrap of ducktape on each side of each crack to help confine the fill to the crack and minimize the mess. dw