should all my a/c lines be icing up?

I've never seen this before on any car. all my low pressure lines ice up as does the receiver dryer. It's about 68 degrees outside and the hood is open and a/c has been on for about a hour. The air out of the vents is real cold .... this is a converted 134a system by the way.

when I say icing up they turn pure white and are very cold to the touch.

They are alright as long as the last 6 inches or so to the compressor are just moist not white.
At 68 temp, it gets hard to charge accurately.