3D Print Preperation

Hello there,

Any help would be fantastic, I've managed to create an output from Grasshopper and I'm curious if anyone would know where I could begin in making it suitable for 3d printing. 

My understanding is I need at least a 0.5-1mm surface to 3d print with no overlapping. Whenever I try to offset I get overlapping. 

Is there a command or way around this, or am I going to have to just be patient and delete and trim all the overlapping.

Many Thanks

Kyle