I appreciate all the good info. I need to buy some new filters to try and dry things up. I don't think my current problem is a clog though... But I don't know for sure.
I can dry the sand I am using pretty easily. At work we have a fairly large oven than I can put the sand into. I have done this before and it works fairly well.
What type of valves are you using? The same type that came on the blaster? Maybe the issue is the valves that are on the blasting unit?
Finger over the blasting tip works great! I use that trick in my siphon type blasting cabinet.