I want to repair the bottom corner of a casement window rail which has rotted. Having used many different types of filler in the past (including 2-stage), all of which split away from the wood after a few weeks, I wonder if Dry-Flex would be a better bet. It seems quite tricky to apply, and I am only a moderately competent DIY-er so I would be interested in peoples' experiences with it. The job is complicated by the fact that part of the corner of the frame has crumbled, so I am almost building a new corner for the frame, rather than just filling a hole. The joint is basically sound though. Any thoughts appreciated.