Half lap joints – panels are assembled using both continuous mullions and transoms. Both profiles are notched out at the joint position to half their depth. The mullion and transom can then be nested into each other. A clip on cap is employed to cover the joint. Production of this type of panel requires a saw, drill with measuring jig or staple table and special purpose notching device. A panel manufactured in this way is more rigid than the square cut equivalent.
The process for a basic 6 pane georgian panel is as follows:
1. Cut mullion to length
2.Notch mullion at transom positions
3. Cut transom bars to length
4. Notch transoms at mullion position
5. Assemble transom bars to mullion and clip centre covers to both sides of joints
6. Fit edge keys to mullion and transoms