[Cob] Problem oven - not enough sand!

[Ocean Liff-Anderson]

The main reason I can see such a fissure appearing is the lack of  
adequate sand, and hence excess shrinkage as the cob dries.  You  
might need to pull down all the cob, incorporate more sand into the  
mix and rebuild the oven!

Sorry!

Ocean

On Mar 12, 2008, at 11:17 AM, Muddy Toenails wrote:

> Hi to everyone on the list-
> i'm struggling quite a bit with this oven that i'm building...
> Since we started laying the cob, two large sections of the oven  
> have fallen.
> we have fixed and rebuilt those two sections (luckily, we were  
> still in the
> building stage so the cob didn't dry too much between the old and  
> the new
> cob), but a new problem has arisen;
> a long, deep fissure has appeared over the oven mouth. There is  
> maybe a
> foot's worth of material that looks like it is in danger of falling.
> We have not yet pulled out the sand from inside the oven. i'm  
> wondering what
> i can do to prevent this section from falling away from the oven!
> Thanks in advance for your advice,
> h.
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