The plastic sheeting is still applied, to protect the polycarbonate during construction.
I had a deadline to meet, which is the visit of David Atkins in 2 days time. I can't do any more on it now, as it's bank holiday and I can't get copper pipes to complete the plumbing.
The plastic and aluminium is less than 100pounds worth, and the thermal collector is an off the shelf radiator. So its inexpensive!
PS. during the Bank Holiday weekend, I have done some wiring in the loft, leading cables to the future location of the pump and thermostat for the Sunbox 2.
4 May : Just in case the PV panel for the Sunbox 2 does not work, or blocks too much solar heat from the black thermal collector, I have built an identical panel (same aluminium section, and identical frame size) that can have clear polycarbonate, and can be dropped into position into the same grooves. I will run the panel with both types, each for a few weeks. I was aiming to get the sunbox built and the panel made in time for the visit of David from Ice Energy.
Scaffolding: There is the problem about how to change the panel without incurring high scaffolding charge. I must decide either to hire in a mini tower and erect it myself, or to make a demountable frame of steel or aluminium that can be stored behind the garage, or even buy some scaffolding, and store it safely when not in use.