I am having trouble with my spray pattern. ( I spray Blackmac) I have tried different tips, played with the pressure relief valve without any luck. the pattern I am getting is like this - ------- - wall Where I get a void at either end. Does anyone know what is causing this and what I can do to stop it, or is this the way everyone's wand sprays? I have called Protect Asphalt where the machine comes from and they don't know. Any help would be greatly appreciated.