Alright, I'll go along with that. You've alleviated all my concerns except the one about scratching the tank, which is enough reason for me to prefer them coated. Most of my tanks are scratched to heck and it makes it a lot less enjoyable to look at them. In any case, its a great idea, I've been thinking about using these for powerhead mounts for a while, nice to know that it will actually work. 