Faro hot tub

[josh lilly]

Has anybody ever made a faro wood burning hot tub with concrete? I would like to do this does anybody have any ideas. I want to make it so it uses zero power and can be heated with fire.

[tim culloton]

Josh, I know for sure that the heating chamber will need to have a steel liner , not unlike an insert for a fire pit so as to avoid heat induced cracks or spalls. The chamber will also need to be vented, obviously. 

I have played around with fire clay additive for mortar when doing a pizza oven some time ago, built with fire bricks though. They are still solid and no cracks have shown, however , I attribute this to the fire bricks ability to expand and shrink.

The tub part can successfully be done in concrete, I am just thinking the hot water would have to run through copper tubing adjacent to the metal fire box to attain its heat rather than heating the concrete itself alla "witches couldren".

The biggest drawback would be the thermal cooling of the concrete when not in use, might you use pex in the concrete as it returns to the heat box? 

I like thinking about this kind of stuff.

[josh lilly]

I could definitely pump hot water into the tub but i was thinking more along the lines of casting a metal base into the tub and heating with fire. Passive solar is also a option but I like fire and the smell of burning Mesquite wall bathing outside. I really don't want to use any power to pump water . I would like a drain plug on the side and a fire underneath and some hot Japanese chicks soaping me down BONSAI !!!!!!!!!!

[jesse felby]

haha. how many japanese ladies in az? my experiance with heat and concrete has to do with external fire boxes and pizza ovens. im not sure if you you can put fire ,even in a metal lined box and not pop your concrete. made a huge external  fire box with alot of masonry and over 2 tons of rock over the fire box as a heat sink. let cure for over a month . made a nice hot fire and watched rocks break in half. i would play around with small fires in steel against the concrete u want to use and see  how big of afire you can get away with. i know a good quality lava rock can take way more heat than a normal river rock. maybe linening the steel with that and u could get away with it. ill ask the masonry guru(my dad) and see what he thinks . i hope this helps  

[Paul Lundy]

I think you could do it like the picture above and keep the heat source away from the crete. Convection would move the water. Wait is convection  the correct term to use here?

[Steve Coats]

I have a friend that has a redwood tub with a underwater woodstove take up about a third of the tub, canoe paddle to move the water works great. I think the stove was around $800 bucks

[Robert Winckler]

They have stainless wood stoves for redwood or cedar tubs. There are two tubes about six inches in diameter running right through the stove where the flames hit near the top of the stove. The stove top sits above the surface of the water and it is top loaded through a hole. The water flows through the tubes as they become heated. My friend would haul the whole contraption by horse out into the Bob Marshall every year for hunting camp. A canoe paddle could speed things along of course.

I like the above design better because the stove wont get in the way of you and your lady friends in the tub. Try coiling flexible copper pipe around a single wall wood stove pipe would be more cost effective but may take too long to heat.

[josh lilly]

This is $ucking awesome.

SK said:

The human stew pot:  I've had this in the back of my mind for a long time.  The site is a little better than the image I've posted.  Totally doable and not complicated.  Those damn Dutch!   http://www.weltevree.nl/ENG/collection/dutchtub_4p-30

[Buddy Rhodes]

That would be the Snorkel Hot Tub. http://snorkel.com/

Steve Coats said:

I have a friend that has a redwood tub with a underwater woodstove take up about a third of the tub, canoe paddle to move the water works great. I think the stove was around $800 bucks

[Mark Podgurski]

All these cool tubs make we want some Ciallis.'

[Jeff Osborne]

Good one..

[Damian Taylor]

Hey Josh. I have had similar ideas myself. 
Currently we are running a Chofu wood burning 
Heater. It is  beautiful, low technology relying 
Solely on natural dynamics to circulate water 
From the tub to the heater (that sits outside the 
Tub). We have ours connected to a 90 gallon 
Galvie stock tank untill I can realize my vision of 
A concrete tub. The thing works amazing heating 
Tub in about an hour if you stay on top of the fire.
We live in VT. And soak in the coldest of outside 
Temps. It always gets too hot where we need to 
Temper with cold water. I believe it would service 
A much bigger tub if we wanted. 
Good luck buddy. Contact me if you want, I should 
Be a sales rep for the co. With as much as I talk 
It up!