I know I'm bumping up a really old thread, but I'm curious about some of the lining suggestions I've read here. People mentioned ways to line a pvc downspout - they mention using mylar and they linked to Nizzy's site and some of his suggestions (polyurethane and silicone). I read through stuff and I still don't understand the actual "how" of it. "HOW" would you use mylar? How does Nizzy's suggestions of polyurethane or silicone work for this? I can't picture it. Any input would be welcome - I love the shape of the soaps that come out of the fluted downspout - so pretty! Thanks!