I am building a resonator guitar with a cone kindly given to me from a guy of here,does the bicuite have to be any special thickness of wood? as it would help me if I could make another one a little thicker.Mal
You want it at least thick enough to support the tension of the strings without bending or warping. Other than that, the thickness of the biscuit and bridge should be determined to achieve the desired string action.
A biscuit around 5 or 6mm thick should be OK..if you need extra height just use a taller saddle insert. Fix it to the cone with a small screw - a machinehead fixing screw should be just about right. Don't pinch it too tight, just enough to stop the biscuit sliding around.
Commercial resonator guitars are often built with the saddle and the "busquit" made in one piece. The way most of us do it is to make the busquit part out of some hardwood or other and then add a saddle; usually into a slot.
Here's a rather out of focus photo of one of my uke cones with a rosewood biscuit and a maple saddle. The saddle is friction-fitted into a slot cut into the top of the biscuit. This gives a fair amount of scope to adjust the action by changing the height of the saddle (providing you've got adequate clearance over the coverplate and under the handrest if you are using a standard metal coverplate).