Hello. I have built a grind box, attached the angle iron and everything, there's only one problem: the angle iron won't slide. I've sanded and grinded down the angle iron as smooth as possible, but it still won't slide at all unless I basically coat the ledge in oil (no exaggeration). I have seen skatepark ledges and other grind boxes, and the angle iron slides much better, some without any wax at all. So my question is: how do I get my angle iron to slide well? (yes, I have tried going faster, it still just sticks.)