|
Post by shilo on Jan 7, 2015 8:02:24 GMT -8
the barrels are 58cm so the half is 29cm what the high of the finished bench? I used to make 35cm benches but 6cm of cob will BBQ my butt
|
|
|
Post by matthewwalker on Jan 7, 2015 9:33:06 GMT -8
I usually go for a finished height of around 18", which leaves 6"-7" of cob over the barrels. They do tend to lift the system height a bit, so if you can bury them 2" or so in the floor it will help. You can also trim them down, since they have extra CSA to spare.
|
|
adiel
Junior Member
Posts: 119
|
Post by adiel on Jan 7, 2015 12:09:25 GMT -8
hi matt how much would you trim it in a 7" batch box system? would it still be a bell?
|
|
|
Post by matthewwalker on Jan 7, 2015 13:43:01 GMT -8
I would trim 2" off of the sides if I had to. Overall CSA of a full half barrel is three times + the CSA of an 8" flue, so there's quite a bit of leeway. I don't know about the "bell" part, I suppose it depends on how you set it up and who is giving the definition. I suspect it will get warm, which is what matters to me.
|
|
|
Post by shilo on Jan 13, 2015 14:46:55 GMT -8
my new idea
|
|
gjh42
Junior Member
Posts: 61
|
Post by gjh42 on Jan 14, 2015 8:03:15 GMT -8
10cm / 4" of cob is getting thin for structure to begin with, and as much insulation as you show will guarantee cracks forming in the thinnest part or at the points where it goes from thick to thin. A very thin layer of insulation (1/4" as Patamos mentioned) could be okay and give the resistance you want in the middle.
|
|
|
Post by shilo on Jan 14, 2015 13:02:33 GMT -8
I mean insulate cob. like clay-perlite or clay-straw etc.
|
|
|
Post by DCish on Jan 14, 2015 13:11:24 GMT -8
Great idea, lets you taper in to get the heat flow that you want. Do let us know the outcome, should be handy to know how much insulation has what effect.
|
|
|
Post by shilo on Jan 14, 2015 13:28:31 GMT -8
it also nice for the ISA
|
|
gjh42
Junior Member
Posts: 61
|
Post by gjh42 on Jan 15, 2015 12:38:11 GMT -8
I could see a thin layer of clay/perlite for heat resistance, then clay/straw with plenty of straw for strength plus insulation.
|
|
|
Post by ronyon on Jan 24, 2015 18:02:10 GMT -8
The barrels in a half barrel bench are pretty durable, right? They don't really burn out?
|
|
|
Post by DCish on Jan 24, 2015 18:15:49 GMT -8
Right. Relatively low temps, and no contact with combustion like core parts have to deal with.
|
|