I got ya..... Most manufacturers use pretty cheap cork nowadays since the price of good cork has skyrocketed (must be tied in to oil ). They almost all use a filler of cork dust and wood glue to fill holes and put a thin coating on the grip. You should be OK using cork dust and wood glue to fill the holes, the U-40 should work as well to seal it. I have only used it a few times, but it seems to be holding up. If you need some scrap cork to make the cork dust with IM your address, I have a bunch lying around.