After making sure the daddy long legs were safely relocated, it is time to clean off the surface. We spray it down with a pretty good stream of water, trying to be sure all the debris is cleaned out of the holes (caused by air bubbles in the concrete). There's sand in there, from the blasting, in addition to your ordinary dirt, dust and such. It's important to get it all out though, so nothing interferes with the bond between the repair material and the underlying concrete...