Painted the keg. Wanted to test it out tomorrow but forget a program I have most of the day, and when I'll get back I'll have lost most of the daylight. I expect a few more sunny days, but from the middle of the next week it will most likely rain, so next weekend is probably out. Now I'm planning to put it to it's place in the morn and leave it to the family the rest and listen their report when I get back.
The sun heater isn't complete, I have to check some plans first and how to do it. Oh it needs glue ofc, would be more cost (by not much tho) but I got some from wörk.
If I have enough foil I will make a smaller reflector, just a cardboard bent twice so it has three faces and can be put behind the keg. Will see.