filling the bench - one question?

Hello Allen, Samatax and everyone interested in rocket mass heaters.

After successfully having setup our Rocket Mass Heater we are at the point we need to finish the bench. We have only one 6 inches diameter pipe running into the mass and the bench will measure, 2 meters by 85 cms by 40 cm, in inches, 78 x 33 x 15, yesterday we filled it with stones and pieces of disposed concrete and clay. I think we reached the half of whole mass. I noticed a lot of water, I also left the heater running for more than 12 hours. So my question is, should we wait for whatever material we already dispose in the bench to dry and then complete the bench or we can go ahead and finish the job now with more clay, more stones and mainly now Cob and leave the whole thing to dry?

thanks a lot,

Carlos

Finish, and burn untill dry.

Carlos : When it comes to doing the fill to make your Thermal Storage Bench, there is No wrong way to do a Thermal Mass ,some are better than others,and some are better
at some jobs than others !

The first job cob has to do is to,create for itself near-perfect mating with the outsides of your pipe the better that the cob mates with the pipes the better ! One of the better
tricks after you get the cob completely covering the pipes is to slap the top of the cob repeatedly with a short paddle like you might use to stir a large pot! We want the top of
the Cob to be shiny wet, but move on to an other region of the Cob before you have puddles start to form on the top !

The next step done any time you stop is to score the surface to lock on the next layer of Cob ! it is all right to use all the rocks, stones, and all the old pieces of concrete that
you can get into the first layer of Cob as long as you followed the other directions first !

The second and third layers of Cob can take ALL the rocks etc. you can get in there without creating voids, again leave a rough surface between layers to lock them together !

You should have already considered your Anatomy and Physiology when you were creating your built-in furniture. As a simple Exercise, sit in a straight back chair with your
legs bent at the hips at a 90 degree angle, with a second 90 degree bend at you knees , now try to stand up without moving your feet back to and underneath your but, and
try standing up! This is why you need to have your bench scooped out at the floor to allow you to move your feet back! All other dimensions are yours to create !

Don't worry about the water, the Cob will dry with fewer and narrower cracks if it dries slowly, but it is the Finish Coat that does the final Sealing of Your bench ! My opinion is
that you should be able to use small fires from this point on, always hot, just not as big as the biggest you could build !

For the good of the Craft ! BE WARM, keep safe, PYRO AL ! As always your Questions and Comments are Solicited and Welcome A. L.

Hi Allen and Samatax,

We will finish filling the whole thing tomorrow and will try to follow as much as we can Allen's receipt.

Guys, any advice on how to fill the vertical pipe that is inside the house, I am afraid the thing can fall apart on top of us. We did not do any work on this since filling the bench is the first step. I was thinking on some structural wires and a wall made by bricks to content the cob.

thanks a lot,

carlos

Carlos : My location is 500 kilometers, above N.Y. City, at 45degrees North Lat., up here we have No History of Cob or Adobe ! Recently, we have had a small Renaissance
in Cob Bread/Pizza ovens, mostly built Outdoors, and needing a structure with a roof over them! Can you imagine the kidding that the builders got for building ' a big mud
oven that has to have a roof built over it?

My only suggestion that I think will help you is to find a copy of Ianto Evans' (et Al) book on building with Cob - ' The Hand-Sculpted House ' - , I think that you probably
can put on hold your finishing your bench and building your Vertical Cob Buttress around your Vertical chimney until you find local Talent or get the book and can practice a
little !

Because so many of us are so far behind in understanding much of the mysteries of Cob, we will count on having you as a future expert on building with Cob. So take and
share lots of pictures, and take lots of notes !

Remember to plan on your clean outs !

For the Craft,and its Future, stay warm ! PYRO AL As always, your comments and questions are Solicited and are Welcome ! - A. L.

Hello Allen and Samatax.

It's been 3 days since we finished filling our bench and we've been burning the heater since. I guess the big work is done and only finish and covering the vertical pipe is left. We will continue with those tasks as the time allows but the main point here is that the heater is fully functional. We luck forward to be able to use the bench and my guess is 2 weeks for it to be fully dried, may be a week for superficial dry. Will see.

I'd like to thank you both for the replies for my questions and you time. I would like to be able to help whoever needs information about this amazing thing and help people to build those heaters around here.

Best wishes,

Carlos and Nara from Uruguay.

Carlos and Nara : Usually at the very beginning of a build, we promise the new member to solve all their problems and declare that 'You will always remember your 1st post!'
This post declares you independent, and moves you from the need to ask 'what do i do now' to look what I did, this post is the one we will remember and the next one is yours!

Please continue to follow these threads, as we will have questions for you! 1 ) We will never get away from needing clean outs ! 2 ) 'T's are very expensive, how do we make
cheap clean outs that are strong ! This would deserve to be a NEW TOPIC ! Anything else YOU can think of !!

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