how do i reglue the pleats? i have 13 shades in perfect condition but one by one each shade has a pleat which has separated from the pleat above it. the pleats that have separated are near the top of the shade. seems like the glue isn't holding them together. they were made by del mar and are 26"w x 36"l and are 90% of the time in the closed position. is there some co. that will apply new glue to the pleat that gave way.