I am thinking about making a racket mass stove for my studio. I was really cold last winter!I have 2 questions. Could I bould a rocket mass stove in an old cast iron bathtub? The reason I'm asking is because there is a tub in my studio and it is to heavy for me to .
The second question is about the materials you are using for the thermal mass. I have read before that of all the stones, bricks, sand, that people use for thermal mass, water is really the most efficient. Any thoughts on this? Thanks ahead of time. Fay

Fay Day : Welcome to Permies, and a Big Welcome to the Rocket Stoves Forum Threads! You will long remember your 1st post here! 16,000 members can't be wrong

You have said that you have been reading up on the rocket mass heaters R.M.H.- hopefully you have already found your way to the good folks at - Rocketstoves.com
If not, Please consider going to - ' rocket stoves.com ' - to get your PDF copy $15.ooU.S.D. of Evans' and Jackson's Great book 'Rocket Mass Heaters' there
is STILL no other book in any language that contains as much "rocket stove family information''! With the exception of going to richsoil.com (Permies sister site ) and
clicking on Rocket Stoves, it is a bad plan to attempt to follow the videos of builds you see in places like You tube/facebook Etc.

What is your existing floor made of where you want to put your rocket mass heater R.M.H. ? While the R.M.H.burns wood very efficiently, without a Thermal mass to
store it in, your heat will just go up the chimney! Will we need to consider some simple modifications to support up to 2 tons of thermal mass ?

I have a beautiful picture of turning the Bathtub over and using it for a double set of 'bells' just after the R.M.H.

Here in the forums you have read where novice builders are told to make up their new R.M.H. outdoors and be sure it works before moving it inside ! To that I would
add that No one should try to use water for thermal mass on their first build ! Come back here often with your Questions and comments your fellow members will stay
the course with you to a successful build !

For the Future/Good of the Craft ! Be safe, keep warm! As always, your comments and questions are solicited and are Welcome ! PYRO - LOGICAL Big AL !

Fay, water might be nice on, paper. But there's several probs with it. Risk of explosion, moisture, legionela, flooding and may be more that i don't know! As Alen said, use it as a bell. Cut a hole at each end, fit two pieces of pipe, soldered, brazed or welded. Whatever works. Then make a suporting frame inside the bath about half way up. May be use old offcuts of rsg, whatever works. put some lose pavers, concrete blocks filled with stones or gravel, or earth, anything to make mass. Then, when you have filled the top part up to the "rim" or near. Clean the rim. put a bead of high temp silicone and a sheet of steel cut to fit the top of the bath, and may be , be discreet. Top that with pavers, , the width of the bath if you can find them. And "voila" , you have a nice bench bell mass.

Actualy i have thought about it before.

Hth.

Max.

Thanks you for your replies. Somehow I didn't spot the 2 ton part. Anyway, my husband just vetoed the idea , not wanting any more projects. It looks like I will be hibernating next winter.