Since it was super hot at the cabin (and no campfire ban), though it would be a good plan to “test” the Cowboy Hot Tub Project. The goal was to place a hose/copper pipe in the campfire and run it back into the tub. The water would be pumped through the hose and come out warm on the other end. After 2 hours, the water should be a reasonable temperature.
Most of the parts were scavenged, but the stock tank was purchased used from a local farm for $200. The water tank measures 10′ long x 3′ wide by 2′ deep. It has two brace beams to keep the sides from falling out. The 300-gallon water tank was filled with a 1-1/2” PVC pipe from the water line to the cabin. More information about the parts can be found at the blog post on July 12, 2015
Once the tank was full of fresh lake water, the next step was to heat up the water to a comfortable temperature. To help push the water, I used a 12 volt DC pond pump. It was hooked up to a deep cycle battery.
I had bits and pieces of 1/2″ soft copper pipe from the old roof top water system. Using a car tire as a bending form, the pipe was bent into a coil. Built up a fire using the “log cabin” style and placed the copper pipe over the flames. It worked pretty well, but the fire needed to be hotter. I moved some the wood around and cut smaller pieces. It let it burn for a few hours and then called it quits for the day.
The next day, I looked around the shop and found a decent coil of 3/8″ soft copper. It was wound up in four coils and looked like it would do a better job. Attached the garden hose to the ends and started to work on the fire. This time, I found an old, round BBQ that had holes in the bottom. I looked for shorter logs and split them with an axe. The plan was to create a small, hot fire inside the old BBQ. Hopefully, the heat will be contained. Once the fire was going well, the coils over the fire. I kept adding pieces to the inside and outside of the coil.
This time, I noticed the temperature was a bit hotter. The extra coils did make a difference. What was really interesting, we the wind increased and blew on the campfire, the temperature increased incredibly.
At the end of the day, it was a good test for cowboy hot tub project. By trial and error, I know what needs to be improved and I got a chance to sit back and enjoy the project. More improvements will follow in a few weeks. Thanks for watching!