So here is my attempt at making the least expensive solar collector possible and then using it to heat our small two person hot tub!
I found an old piece of 5 layer lamninated plywood, It'san old sign from I recycled from a local business. - Cost to me $0
Also recycled, I found this piece of tin that we pulled off of an old garage that we tore down years ago.
After cutting the board down to the size of the tin, I had just enough to buid the shallow walls of the solar collector
I went to the local hardware store and bought:
Generic black spray paint - $1.75
A Cheap 1/2" diameter 50' garden hose - $13
Some 1/2" T Connectors - $4
2 1/2" straight connectors - $1.50
A cheap roll of plumbers metal tape - $1.75
Total: $22
Screwed the shallow walls on and painted the part that will be exposed.
Screwed on the tin, used a whole can of spray paint painting it,(sorry environment... will have to find a friendlier way to do it next time.. ) and scrapped the idea of using plumbers tape to attach the hoses, instead I found some 1/2 insulated staples laying around our shop. Using a large nail to pierce the starter holes in the tin, the staples made for a quick installation of the hose.
As you can see I left this end of the hose intact as I bought it. When put to use, it will connect to the drain tube of the Hot Tub and be the water input for the Solar Collector.
The water output end of the hose need to be cut off to fit through the wholes cut in the end of the Solar Collector...
Some close-ups of my stapling...