[Cob] Iron in cob

[Damon Howell]

Robert,
	Iron in cob isn't a good idea, especially with concrete encasing it.  
When iron gets wet it rusts. Even though the cob dries out, the  
damage is already done to the iron because of an irreversible  
chemical reaction. Concrete wicks moisture, so they say, which would  
draw all the moisture towards the iron too. I'm not sure why wood is  
preserved in cob. Perhaps because the cob petrifies it. I remember  
someone say they tore down part of a wall for an addition or  
something, and the nails they put in the door frame (for the cob to  
grip) were rusted away but the part of the nails that were in the  
frame were fine. They may not have used galvanized nails either, I  
don't know.

Damon in GA