Some friends and I have been trying to make a bank spot. We already put down the concrete and it's looking pretty good, but its looking really "flaky" like if we skated it, especially grinding the top, it would fall apart pretty fast. We were thinking there might be some type of a think paint or something that would hold it together a bit better and make the lip of it grind. If we end up having to redo it or add more concrete is there anything we should do differently or a specific type of concrete we should use? Anybody have any tips?