we've just finished our rmh and had our first fire this evening. it all seemed to work fine, but i'm wondering about how to best use our heater while drying out our "wet" cob (12 foot cob bench). should we build up heating time or just fire it up very hot right off. how long before our bench should be "dry".
Michael Carman : Boy are you going to laugh ! (In about 2 years ) No it will not take that long to dry out it just will seem that way! Anyway, it is going to take weeks.
I expect that you Need to use it now, so your question is moot! E & E Wisner still do a few complete builds and leave the owner with a RMH already fired and expect
it to be put inservice immediately !
I believe that i am making a safe recommendation with due consideration to the time of the year ! You are first trying to dry the Combustion core area out,when you
can build a hot enough fire so that looking down inside the burn tunnel (in a darkened room) you can see the firebricks glowing a dull red,the combustion core is now
dry, reduce the amount of wood by 1/2 using a brick across the top of the feed tube to regulate Your RMH (weather allowing,),so that you continue to hear your
rockets roar, at about this time you are starting to say where is all this water still coming from and are about two weeks from a dry Thermal mass, if you need to run
it more wide open for the space you Have to heat it Should be O.K. and don't be alarmed by the amount of wood you are using, as your Thermal Mass dries out
suddenly you will be burning less.
Welcome to the Ranks of Rocketeers, and let us know how you are doing ! For the good of the Craft Big AL
Success has a Thousand Fathers , Failure is an Orphan
Hi Michael; Light it up and burn it hot! It will take a minimum of 2 weeks but could be a month or more depending on conditions. Your core will dry fast but the far end of your bench will take awhile, expect water dripping anyplace it can escape. As big Al said your wood consumption will go down as your mass heats up. A cheap digital laser temp gun is a most valuable tool for monitoring your temps. Once your bench is warm you will be amazed at how easy it relights and how long it holds heat.
Not all who wander are lost... J.R.R. Tolkien
We don't have time for this. We've gotta save the moon! Or check this out:
A rocket mass heater heats your home with one tenth the wood of a conventional wood stove