Lots of changes to the project, but the end results was a hot bath in an off grid situation. The first was to move the tub to a better location for my family. The old tub was located down at the lake, which can be tiresome walking up and down the hill to use the washroom, get more beer, etc. The plan was to put it where the current outdoor shower was located in between the outhouse and the guesthouse. The only setback was a large Pine tree was in the way. So, instead of cutting down the tree and getting distracted from the task at hand, I decided to use the existing 5′ long, cast iron claw foot bath as the tub. It was a little bit easier to move around and the water would heat up faster.
The next step was to use something to contain the heat around the copper coils. The campfire worked but it didn’t get hot enough. After my wife’s suggestion, we had a spare wood stove in the guest cabin. The previous owner purchased it and it was not installed. It was a perfect size, not too heavy and it fit nicely in the new space.
Once the tub and wood stove was in place, the next step was to run the 1.5″ PVC water pipe from the main line to the tub. I had to do some careful planning and ensure everything fits the future plans for the water system. (Which was to move the water barrels off the roof and under the cabin. As similar to an RV set up, we would use a 12-volt pump to move the water up to the tap) I was really pleased that there were spare fittings that could be utilized for any kind of angle. Once the fittings are glued, there were no second guessing. Only had one screw up a forgot to glue the pipe together under the guest cabin. Not the end of the world, but I’ll have to keep the psi of water pressure to the minimum.
The next step was to modify the copper water coil to fit inside the McClary woodstove fire box. To make a water coil, one end was capped and table salt was poured into the copper pipe. The pipe then could be rolled or bent into a shape without kinking/splitting the pipe. With a little time and patience, I managed to form a pretty good coil. The next plan for a coil would be about 6 inches in diameter. The water coil was placed into the McClary woodstove fire box. The “in” and “out” ports were inserted through the stoves side vent holes.
By this time, it was the end of the day and getting late. I still wanted to test out the woodstove and the water pump. Did a test with a large metal crab pot and ran the water through the line. It took a while to get the fire really hot in the firebox. I’m sure if the water coil wasn’t in place it would heat up much faster. After 40 minutes and lots of small, dry twigs, the fire really started to make some luke warm water. I threw a couple of dry cedar logs in and stopped for dinner. About an hour later there was some coals and the water circulating was gradually getting hotter.
Music credit: “Rural Stride” by Josh Kirsch/Media Right Productions & “Swamp Stomp” by Silent Partner (YouTube Audio Library)
Since it was super hot at the cabin (and no campfire ban), thought 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 and worked quite good.
I had bits and pieces of leftover, 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 Tube project. 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!