anyone used a toilet bowl in rocket mass heater/stove?

I thought it might make a good vortex/riser component...

Well Steven;  
That's certainly thinking outside the box!  
Couple reasons I don't think it will work.
1st)   I don't think it can stand the thermal shock of instant high heat, I think it would quickly crack.
2nd)  You want your riser to flow heat quickly and efficiently.  Turbulence in the flame itself is OK , forced corners  would just slow it down.
3rd) Personal preference here ... In my opinion, it's literally butt ugly... who would want a toilet in their wood stove ?
4th) Don't let my opinion stop you. If you think it will work then give it a try!    Innovation is the Mother of invention !
I will happily check out your photo's & post, if you build such a thing.... but...even if it works super dooper good ... I don't think I would want one.

Kind of off topic but I am pretty sure I am the only one alive whose ever had his hand shredded by an exploding toilet.

What happened is, I needed to do some work behind the toilet, so I undid it, and for a lack of a better place, stuck it outside for a few days. It was spring so there was some warm and cold cycles as it sat outside.

So a few days go by, and I decided to install it again, and haul it back in. I hook up the pipes and turn on the valve...

SMASH!

What happened is, the water inside had half froze, so when I turned the water on, it acted as a water hammer, and the ice inside shattered the toilet. With my hand right there, the super sharp ceramic shards shredded my hands from the porcelain shrapnel.

As I said, I am probably one of few people who can lay claim to this incident.

Travis Johnson wrote:Kind of off topic but I am pretty sure I am the only one alive whose ever had his hand shredded by an exploding toilet.

I consider that extremely relevant.  Wow.  Important to know if one is considering innovating with commodes.

Kim Goodwin wrote:

Travis Johnson wrote:Kind of off topic but I am pretty sure I am the only one alive whose ever had his hand shredded by an exploding toilet.

I consider that extremely relevant.  Wow.  Important to know if one is considering innovating with commodes.

Somehow I have lived an interesting life without really trying. "Hey, has anyone shredded their hand from an exploding toilet? If you have, raise your shredded, bandaged hand." (Travis hears nothing but crickets. BIG crickets)

well those thoughts certainly give me pause... esp. the exploding bit! I was thinking maybe upside down, with the double walls acting as the gasification chamber. As it is already fired in production I thought it could handle the heat. If I try it I'll document and share...

The problem with using something ceramic is not that it cant handle the heat, it's that it can't handle differntial heating. Some parts will be hotter than others and expand at a different rate. If you are lucky it will crack, unlucky it'll explode.

I can speak from experience that it won't take the heat. I had a wwoofer here who tried using one as a grill for cooking food. Put the wood in the bowl and he figured the air would come up through the bottom. Wallah, perfect fire. Before he even got the grill in place, the toilet cracked. But he did persist and manage to cook one meal. It's a shame that old toilet bowls can't be converted to outdoor cookers.

Well, my boss/landlord just told  me to “bust it up and put it in the trash piece by piece.”  He didn’t say how to bust it up though.

Hmm! It's pretty dense ceramic material, and there are craploads (ha!) being sent to landfills all the time. If it's smashed up or frost-shattered, would it have value as thermal mass, mixed with clay etc.?

Rocket science has gone to pot.

I think old porcelain fixtures of any kind would work nicely as thermal mass, or as rubble trench fill or a subfloor drainage layer - it would not absorb or wick moisture.

I have a bunch of old radiators my then-brother-in-law gave me from a construction job decades ago. I used them as retaining cribbing at the edge of my driveway, but have been looking at them for building into the walls of a RMH bell - highly conductive and compact thermal mass that is also strong and has nooks and crannies to hold cob tightly.

If I had a spare commode around, I would absolutely try this! Experimentation is the fun part. Maintenance, in my opinion, is a drag. The idea seems so ingenious! Sure something unexpected will happen but that is useful too. I hope someone will go out into a safe place, play in the mud, pack that mud around the pot and tell us what actually happens. Permies is a hands-on sport! Speculation without experimentation is just another call center job.

Amy Gardener wrote:If I had a spare commode around, I would absolutely try this! Experimentation is the fun part. Maintenance, in my opinion, is a drag. The idea seems so ingenious! Sure something unexpected will happen but that is useful too. I hope someone will go out into a safe place, play in the mud, pack that mud around the pot and tell us what actually happens. Permies is a hands-on sport! Speculation without experimentation is just another call center job.

Just make sure you're in full protective gear when you try this please! I'm all for experiments, but as Trace identified above - very shape shards - cut good things badly. I've seen a video of a guy using shards of ceramic to drill a hole through a ceramic pot.

I actually tried something like this years ago.  I put an old toilet up on some blocks and fed a gas line from a propane tank through the back end to just inside the bowl.  Filled the bowl with lava rock.

I asked some friends if they'd like to come over and grill out.  When they came over we went outside with the prepared burger patties, I flipped up the lid and seat on the commode, placed a round grill rack over the hole and fired her up.  It cooked the burgers just fine, but no one really wanted to eat them.  Lol.

BTW.  The bowl did crack before the evening was over.  

Just to be clear, I wasn't proposing lighting a fire in the bowl, or using it for grilling.
It was for the heated gas vortex and dispersion, using the existing channels in the bowl and drain, which presumably are designed to optimize flow of liquid, and might have a similar effect on heated air.

Steven Lindsay wrote:Just to be clear, I wasn't proposing lighting a fire in the bowl, or using it for grilling.
It was for the heated gas vortex and dispersion, using the existing channels in the bowl and drain, which presumably are designed to optimize flow of liquid, and might have a similar effect on heated air.

Still going to see a lot of differential heating and thus expansion so it will likely break.  One other point is your cross sectional area will likely be too small.