Masonry sand + sodium bentonite mixing trials

Initial target is 4% moisture with minimum clay.

Sample	Sand g	Bentonite g	Dry Post Mix g	Water-g---	Wet Post Mix g	Observation
1	1000	40	1037	70	unknown	Close if tightly compressed
2	1000	60	1061	40	1100*	About the same no worse
3	1000	80g 7.1%	1080	40g 3.5%	1120	Good enough to use

On the second sample I lost 20/60 grams of clay in part due to the wind.  So I am doing it over with a 2 gallon bucket and a snap on lid.  Would prefer a screw on lid but don't have them in this size.  After tumbling in the 2 gallon bucket my weight was one gram extra.  Well within the expected margin of error for this.

* I discovered that weighing the spray bottle does not work as significant water is lost due to evaporation and maybe droplets that never hit the sand.   A better method is to spray the water onto the sand on the scale while mixing.   That lets one hit the exact target number.  This has me unsure of the water in sample 1.

I am storing sample 2 in a ziplock bag.  Will make an observation regarding it again in the morning.  Need to bring it in so as not to freeze.

Added a few more rows to the table.

1. Progress on making new green sand. After doing 3 test batches of approx 1 Kilo each I settled on a mix of 7.1% clay and 3.5% water. This test batch consisted of 1 Kilo of masonry sand, 80g of bentonite and 40 grams of water. If needed I can go higher on the sand and water but this feels like it will work and I have wiggle room. Added water with a spray bottle to the mixer. 
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4. Notes on combining the sand/clay/water in a cement mixer. Add dry ingredients and tumble in cement mixer. I erred on the side of caution and sprayed water over the sand. A fine spray helps prevent lump which happen when using a cement mixer instead of a muller. Initially I sprayed water with the mixer stopped. Mixing by had between each spraying. When I got to where it was no longer dusty I sprayed with the mixer running without the lid. Did not come out as well as the test batches I mixed by hand. This has small lumps that while not all clay, are clay rich. Put the stuff in covered pails. Will see if the lumps lose any of their moisture with time. Maybe breakup with a bit more time in the mixer if they do. If not I will break up what I can with a riddle then dry and ball mill the rest so I can mix it back in. With the lumps being clay and moisture rich the rest is short or them. Could be used as is if I riddled the first bit on the pattern to avoid the lumps. But I want to see If I can get it to where it should be to determine if using the mixer for adding water saved time. Next Morning: The lumps were still there but soft and smashed easily with ramming. Sand is useable.