Hello Ilia, thanks for taking the time to answer.
1. I thought I could weight out several lots of lime (as I would when testing a glaze receipe)and test by adding varying amounts of water...hoping one would work really well.

2. In all my reading I did not take in the fact that so much sand was added to the final painting layer, I thought it would be almost pure lime...a smooth painting surface.

3. Anyone who has had experience will have a "giggle" over this.....not having an experience, I mixed up the lime putty last Friday and today I finally used it. BUT didn't wet down the boatd and didn't add any sand.
Thought I would try what I thought would be the final coat. It's raining here and my studio is dry (I think)..but not dry as in California. The lime putty smoothed out real nice and stayed damp for a long time...in fact I had to wait awhile before I tried painting. Got pretty muddy in the beginning.

Ilia...YOU ARE CORRECT...it CRACKS!!!! Really bad!
But tomorrow is another day...and I'll scratch up the board , wet it down tonight and try again tomorrow.
ct