Got it back together yesterday after the Monday morning water run, this time (so far; it fooled me the first time) leak-free.
Max temperature with good overhead sun, no glass cover:
…barely one’o’those. Which is just enough for dish washing or a minimal shower with max sun. So I’m going to be ordering more black hose, which I gather is available on Amazon. Big Brother donated the 100′ currently up there.
That seems like a surprisingly low temperature. Adding the glass should help.
My earlier comment was daft! Anything over 120 degrees is considered to be a scald hazard, so 140 should be an okay temperature for your purposes. (Assuming normal caution) Now you just need more, and you know how to get it.
I would expect the glass cover to help a fair amount – the greenhouse effect. Long term, I would worry about how well the hose will hold up to the heat, but we will see.
I suspect that the ideal setup would involve a smallish insulated storage tank and a small circulating pump, but that is probably for the Mark II or Mark III version.
I wonder if you could flatten the hose a bit, that should cut down the amount of “dead” water space and increase the heat transfer.