This is really a two-person job!
You need:
Cement based adhesive
Grout – the same as you used on the panels
Masking tape or clamps
Sponge
Rags
Mixing tool
2 buckets – one for clean water and one for mixing the adhesive
A smaller container for mixing the grout
Mixing tool for adhesive and grout
Scissors or knife to open bags
Spreader with 6mm notch on one side
To adhere the panels to the Stobie pole:
Mix about a quarter of a 10L bucket with adhesive (about 3 cm water then cement based adhesive powder). Mix well - let slake, mix again (2 minutes – 2 minutes - 2 minutes) well!
Wet the Stobie pole, apply scratch coat.
Lay the mosaic on something soft like bubble wrap when you apply the adhesive to protect the front of the mosaic!
Apply a scratch coat to the back of the panel and then then use 6 mm notch spreader the adhesive in one direction on the back of the panels.
Make sure any overlapping pieces have adhesive applied.
With two people, attach the lower panel. Wriggle it to properly attach it. Then use masking tape to keep it in place. You can use clamps, but they must stay for about 12 hours and might be stolen in a public space!
Line up the top panel and attach and wriggle gently. Make sure the mosaic lines up. Make sure any overlapping areas have had adhesive applied.
Line up both panels.
You can now grout the overlapping area.
Make sure that the very top of the panel is very well glued to the pole and no gaps.
Clean any adhesive that has come out on the side and spread it along the joint. Make sure that the side of the Therma sheet is covered with adhesive!!! In order to seal it.
Clean up grouted area.
Stand back and admire your work!