Last summer I gave up on my improvised solar water heater because it sprang a theoretically impossible but quite substantial leak. This morning I pulled all the innards down to see if I could find it.
It’s just good quality black garden hose. Not made for the temperature in that box, to be sure, but it really shouldn’t leak until the hose completely deteriorates – and then it should unmistakeably leak.
I pressurized it, no leak. Left it out in the sun all day. No leak. So why was it leaking before? Tomorrow I’ll put it all back together and see how long it works. It’s kind of handy, if only the water would stay where it belongs.