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Brendan Edwards

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since Jul 17, 2015
I have a number of relevant skills in regards to Permacultural and construction concerns including:  General Contractor in City of Baltimore, Concrete counter production and design (D&P),  steel welding, basic and finish carpentry,  cob, humanore projects,  well-designed houses and architectural products from both new and used materials, Electrics, Plumbing, Rigging, pro-Lighting   basic farming experience and Permy (lived in San Juan Islands and worked on many projects including SSI Seeds).
Hiroshima-shi, Japan
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Recent posts by Brendan Edwards

Sorry if this is preexisting..  I'm a bit pressed for time.   I am trying to get some activated carbon to make a water filter good enough  for showers  and washing clothes.   My biggest concern here is agricultural run off.  I have a very shallow well.   my thought is to get some PVC  maybe 75 mm  ...   X   400 mm     put a narrow in and out on it...   pack it with activated carbon and sand ...    I'm curious who may have tried this??   does anyone know what  granular size the carbon should be??   can I use regular charcoal temporarily???   my understanding is that the granular size isn't  so much  important if I have enough medium for it to go through since it still has to pass over the surface.   any  ideas would help,,  I need to get this done.   I have reg charcoal now ...  I can get the activated in a few days.  oh yea,  I have a pump to feed this so my filter should run under pressure from that.


1 year ago
That's a lot of good information,  merci!  My cafe opens in a few days so I'm going to do a quick and dirty and temporary fix today.  get it working without mortar for now. get rid of the extra steel and use the drum can as the coooking area.   I'll take some pics and make some notes.  this will give me a feel for things,  get past the 1rst week. (in japan there is a big spring golden holiday week, after that business is very slow for a bit) ---  basically I'll re-situate it and use a lot of mass around the can to keep the heat up..  so it will work no matter what imperfections it has.  luckily I have more wood than I know what to do with because I run a carpentry shop.  

K,  time to get to it!  I have muffins to bake!
2 years ago
K...  just got up and having coffee... read your addendum...  I think I get what you're saying.   I have immense amounts of construction debris.. literally mountains...  especially these roof tiles..  stone fragments and urbanite/blocks  imagine a roof 15 meters on a side being replaced..  KAWARA  tiles are 25 cm on a side ..  curved.  I've experimented with them in oven construction as heat reflectors and insulation..  they are difficult to work with due to shape,  but I have a thick stack idea that may work..  like they can stack to them selves evenly.  the concrete fondue thought besides funny is kinda what I had in mind..  

OH MAN!!  what about the steel frame I built?  LOL  ..  so I've come to the realization that my idea of a portable device ain't gonna work out without some serious purchases of high temp ceramic insulators and precise welds etc...  so yea.,  I think I need to make this thing a permanent install...  so:

- I'll put it closer to the ground.
- eliminate the steel J.  
-create a kawara stack burn/fire feed area and put the drum on that.  
-I am going to increase my J tunnel volume..
- I will eliminate the steel plate that supports the fire bricks...  
- I'll build an insulating case around the thing out of stone debris and then bury the thing in a mix of stuff..  
-I'll decrease internal airspace where I don't need it and replace it with some heat absorbing material (stone/clay)

I have some clay straw mix that made up wall tiles which I can excavate from the debris..  I have vermiculite...

How does this sound ?    

I may try to leave the exhaust where it is for now...  ,  but build a baffle around it so that the air has to come up from the J,  go around  the oven stone, cooking area and then back down...  and out..    but if I have to move it..  you say near the door?   why not the back?  

2 years ago
HEY SMAX,  I read a lot of that link and the summation seems that I have more problems than insulation.  metals being the leader.  I'm in Japan.  clay has been hard to find or costly.  fire brick is costly.  I have drum cans and regular stone and concrete..  all of which I've already destroyed in my experiments/...   I've gotten my hands on some fire mortar...  a ton of fired clay roof tiles..  drumcans...  vermiculite...  hmmm...  I still think my can is too big for the 4" feed...  but something is starting to occur in my imagine..  tired..  gonna sleep on it.  thanks!
2 years ago
SMAX,  I think issues are solved
2 years ago

its a drum can..  I've got great draw..  seals are pretty good.  I am not yet insulated anywhere.  it gets hot,  but not very.  took a long time to get warm inside.  

If you look at the pic you'll see a bunch of fire bricks,  like 16 of them.  They are sitting on a steel plate.  I've got approx 4 inch tubing making up a j channel.  my vertical is over the 4 of the 1-2-4 ratio..  but as I said my draw is very good.  It all works,  just not hot enough.  There is a vast amount of heat being generated ..  around the j channel especially at the upward turn toward the oven.  I'll give my diagnostic and I hope somebody can set me right..  I need this thing working well enough to make some pizza by FRIDAY...  not too tight!

Insulation will help.  but if I am feeding an adequate system would it still get hot ..  just not maintain???  or what?

the steel plate that supports the fire bricks is not a tight connection.. I figure what is occurring is the j tube is sending that heat up and roasting the  #$%^& out of that steel plate which is not transferring sufficiently to the bricks. Since the draft is good and there is no leakage apparent..  then the heat is being created.  the exhaust is not excessively hot or smoky so the burn is good.  

The heat I reckon is being lost in 2 places.  
1.  the metal plate is getting hella hot and reflecting the heat downward to the can which then radiates it out

2.  the j tube at the lower section joint is red hot. so that is clearly a major loss.


- drum can is too big for a 4" feed tube?
- j tube riser is too long and is losing heat on the way up.
-steel plate is counterproductive in that it is reflecting heat away from intended area...
- lack of insulation is obvious concern,  but I am certain that the other issues are bigger than that as I am not registering a lot of heat coming from various regions of the system. ..  (I have vermiculite and clay mix ready, but I wanted to test the overall system before committing all the material)


I have 8"  pipe available but it seems huge!!
I could shrink the can.  
I'm certain the plate under the fire bricks is reflecting heat away..  so I can solve that ...  


I think the can is too big for a 4 inch feeder if I want high internal temps ..   It's obvious that the up tube on the J should be sorter and I should insulate,  but i don't have confidence this will solve things.
I figure I need to make my channel bigger or my can smaller.  Is 8 inch nuts?    k gotta eat  /...  thanks!

2 years ago
K I read it, thanks! I've got an idea that I think will work using the ideas from the paper you linked and a drumcan retort which I already have... Imagine a drum can maybe mounted on a few stones sitting at the edge of the trench... so there will be space for air feed and wood material continuous from the trench up into the can which sits over it at the end but partially dug in to the ground... The thought is that the can will quickly add useful volume to the cook. So, Fill the trench with all this long uncut stuff, pack the can, get the whole thing cooking then lid the can, toss the junk metal roof panels over the trench, add some soil to seal the gaps a bit and wait... I can quench it with some water to stop the process after a few hours if I think its not sealed well enough.. Quick and dirty, but will give me some usable material, more than just incinerating the whole lot... It'll leave useful soil amendment and some stuff to roast meat with...

If anyone else has any thoughts I'm definitely interested... I hope to do something with a significant portion of my debris in the next few days..
3 years ago
Just looking for any pointers or thoughts on my need for quick and dirty demolition debris reduction. I'm rebuilding an old house and have so much wood I need to reduce. I am very busy with the construction and don't have time to mess too much with it. It's also difficult to move it much, so I was thinking I would do a trench or pit biochar cook. It does not need to be terribly efficient, just simple. I thought I might try to grab some junk metal roof panels to cover with .. I also considered using a 55 gallon drum as a sort of riser to drive the heat since I can access them.. I have way too much to load drum can retort and do not want to waste time cutting timber. Anyway, if anyone has any notes on how to get this working easily, I'm all ears!

3 years ago
thanks for sharing your thoughts, it helped me get closer to how to proceed.
3 years ago
Your description sounds somewhat like what I was thinking.. like a feeder tube system... is yours just a network of brick channels underneath the hearth or what? can you give me a quick sketch? Yours sounds scalable which I wasn't sure of being able to do easily with the Pompeii brick oven for instance. What are the dimensions of your feed tube, channels and exhaust approx? I guess for this size I would make a fairly thick clay dome with perhaps a brick base to support it.. steel strap ring for tension?


to admin who posted vid link... You figure the vids will solve these issues pretty roundly?
3 years ago