H F Sandblast Cabinet won't suck

I had an old fridge left on the property so I put it in the shop. I decided to use is as a dryer. I coiled up 20' of 1/2" soft copper line, put it in the freezer section, with two holes drilled in the side, ran the compressor line to to one, other side to a tee with a drain valve. From there it's about 40' of copper line to another tee and drain valve, before it gets to the water separator. With long compressor runs I'll get a little water in the separator but not much. The first drain gets most of it even when I have the fridge off.