ZBrushCentral

ZBrush 4r4 p2 and unified skin?

I would like to take a ztool in edit mode and have half of the model masked and the un-masked ares unified skined with a smoothness of 0. The mask does not allow this to happen it does the whole model. So how would it be done.
Thanks

Use a Selection brush (Ctrl+Shift) instead of a Mask brush (Ctrl) to hide the part you don’t want skinned. ‘Make Unified Skin’ will only skin the visible portion. If you expecting your mesh to be half skinned and half not skinned, then I doesn’t work that way.

zber2 thanks for the reply - ok doesn’t work.

I have also tried the zproject brush to project the 0 smooth tool onto the non 0 smooth tool and zproject brush doesn’t want to work in doing so - which leads to the question does zproject brush work on any ztool or just the 3dplane tool (which is the only video tut provided by Pixologic).
What am I doing wrong to not get zproject brush to work on transferring info onto the other ztool?