I am trying to figure out how to create a hot tub in the bed of my truck. In the past i have made a pool by putting a tarp in the back and filling with water but now i want to heat it for winter use. Do you guys have any ideas?

I was thinking about hooking up a pump to a hose that i can run through a coil in a 55gal drum which i will burn wood in. What do you think?

 

Pipe from the exhaust into the water? hot exhaust = heat + bubbles?

 

but i dont think that would heat up the water enough

What i was thinking was taking a bilge pump(or something similar) and hooking it up to a pipe that runs through hot coals. My only problem with this is that I think copper line is too thin to pass a large amount of water and if i was to sweat copper pipes together in the coals they would just come apart.

 

Hot tubs loose heat at a high rate especially in winter. Adding air (for bubbles) really takes the heat out of them. Even 220V hot tubs take hours to get up to temp and then struggle at holding it when the cover is off. Takes big heat to keep one cooking.

Are you just planning on filling it hot and then going or do you want it to produce heat while on the road?

 

no just when it is parked in my driveway. I have driven with my bed full to the brim with water before and it was reckless. When i hit the brakes I had a tidal wave come over the top of my truck. This setup will be totally temporary.

If you have ever burned wood in a oil drum it really does produce alot of energy. It can burn for days after putting in the last piece of wood. I just want to figure out how to harness the heat to warm the water.

 

Use your wood burning barrel and see if you can get the copper pipe that bends by hand. I wanna say its type M, but I'm probably wrong. That way you can make one continuous coil and keep the fittings outside the burner. Pick up a small pool pump or just a cheapo pump at harbor freight. 1/2 to 3/4 should do. If you get too small of one, the water might cool down before it gets a chance to heat up the stuff in the bed.