Boolean Self?

Iv had a few problems with the Boolean modifier not doing what i think it should but the main thing i want is to Boolean an object with its self.
This is mainly for 3d printing reasons. If i had intersecting meshes in the same model i want to collapse them all to one continus mesh. Some times it works and sometimes it comes up with some error in th boolean object selection fild.
Iv tryed bool tool a little but hangs for a very long time and often crashes.
Is there another way of doing this ?

Thanks
Ally

The boolean modifier uses two objects and two separate objects only. If you have one object then you need to add a second to your scene or separate part of your object to make a second object

Supply example blend file to clearly demonstrate what you want to do/

You could try to wrap it up with another mesh using boolean:

Blender now has edit mode boolean available in the latest version. It also has knife intersect that could be used to cut the intersections and separate the parts, so that you can remove the extra. Both are in faces menu (ctrl+F)