How can I test the % of clay in clayey earth?

All in the title...
The clay must be mixed with sand, and the % vary according to the earth we use...
Then, how can we estimate our local earth?

Thanks, it looks really good, I will try it!

What would be the natural % that can be used to make cob without needing sand?

I guess we must avoid any organic matter to make cob?
only earth from deep down?

http://www.pequals.com/at/natoven/making_cob.htm
there is no silver bullet recipe. but trial and error basically. the website above chronicles one persons testing. check it out. some people swear it is so easy to do. good luck. I've researched hours on how to and this and the first link were some of the ones i came across.

Paygh Stedman wrote:http://www.pequals.com/at/natoven/making_cob.htm
there is no silver bullet recipe. but trial and error basically. the website above chronicles one persons testing. check it out. some people swear it is so easy to do. good luck. I've researched hours on how to and this and the first link were some of the ones i came across.

Great info, best description I have found so far and includes basic tests to let you know that the stuff you made is good to use.

Paygh Stedman wrote:I've researched hours on how to ...

That is the permie way, thanks!

It is so much saving energy that we do not spend our time looking for the same things!