Wood-fired Hot Tub
Perfect for 6-10 friends. It can be carried in the back of a small pickup truck. It takes about 3 hours to get up to temperature and cost about $650.
-55 gallon closed steel barrel ($30)
-Barrel stove conversion kit ($50)
-14 2" x 4" x 8" firebricks ($30)
-2 2 foot sections of 6 inch black stove pipe ($13 each)
-50 feet of 1/2 inch flexible copper pipe ($80)
-10 feet of 1/2 inch rigid copper pipe ($15)
-10 1/2 inch straight pipe fittings ($5)
-10 1/2 inch elbow pipe fittings ($5)
-plumbing solder and flux ($5)
-Rubbermaid 300 gallon stock tank ($300)
-1/2 horsepower centrifugal water pump ($40)
-10 foot garden hose ($15)
-1 foot 3/4" CPVC pipe ($5)
-assorted fittings to connect tub to pump and stove with garden hoses ($50)
-ground fault switch to turn on pump ($15)
-jigsaw with metal blade for cutting holes in barrel
-hacksaw for cutting pipe
-drill with sharp drill bits
-propane torch for soldering pipes
-shop vacuum with blower attachment (optional)
Step 1: Build barrel stove
Get a 55 gallon steel barrel with a closed top. I got mine from a guy in Bradford, VT who calls himself the "Barrel Man," but if you don't live in the area, you can usually find them on craigslist. Make sure you get a barrel that hasn't been holding anything toxic, since you'll have to spend a fair amount of time crawling around the inside during the assembly process. This barrel formerly held palm oil, and there was a small puddle of it on the inside (it had the consistency of crisco) and every once in a while I accidentally stuck an elbow in it.
I bought a Vogelzang Barrel Stove Kit, Model# BK100E from Amazon.com. Assemble the stove following the directions in the kit. The kit comes with the door, the chimney collar and the legs. The stovepipe is not included in the kit. I bought mine at Home Depot.
When cutting the holes for the chimney and collar, make sure you use a blade designed for cutting sheet metal, and when drilling holes, make sure you have a sharp drill bit, otherwise it will take forever to drill your holes.
After assembling the kit, I added firebricks to prolong the life of the bottom of the barrel. I used 2" x 4" x 8" bricks there were 3 rows of 4 and a final row of 2 for a total of 14.