[Cob] Rototiller mixed cob verses cinder blocks

[Henry Raduazo]

	After two workshops I think it is clear that an experienced block  
laying crew will leave a cobbing crew in the dust as far as speed  
building however, Considering the way I lay blocks (slow and crooked)  
I think we acquitted ourselves very well. Today with the help of a  
few teachers from a local summer camp program we built a foot and an  
inch or two by 17 feet and then did an another 8 inch by 17 feet on  
another wall. I have also experimented with solo mixing and I feel  
that even if there are no more workshops I will have no trouble  
finishing this wall myself.
	Even though this was slower than what a professional block crew  
would have done we saved considerable time by incorporating two  
windows into the cob with out stopping to frame and install as would  
have been done had we been working with block.
	In each case the mixing process was the same. One wheelbarrow of  
recycled cement rock dust was poured out on undisturbed earth and  
soaked. We then attack this pile of rock dust with the tiller using  
the rototiller to both mine the soil and mix it with the rock dust.
	We wet the mix as needed and when enough clay was picked up and  
incorporated by the tiller to make a sticky mass we added 1/2 to one  
entire large trash bag of chopped straw. We attacked this with the  
tiller mixing just long enough to evenly incorporate the straw into  
the cob, then lifted the cob with a dirt fork and moved it to the wall.
	There will be additional workshops during the next month till I am  
finished. Anyone wishing to try out tiller mixing call or send an e- 
mail. raduazo at cox.net or (703-360-2316).
	Also for people living in the western suburbs of Washington, DC I  
will be building a foundation for a children's playhouse at  
EcoVillage in Lovettsville. VA on Tuesday starting at around 10:00 AM  
and on Friday and Saturday we will have two foot mixing parties.  
Bring your own 8' x 10' tarp if you want to mix.