I used 1 pound of alginate in 7 cups of 80 degree water. It set very quickly, but not too bad. Next time I would make the water cooler or add more to slow the setting. It has a pleasant smell.
I made a mold form from old cardboard, lined with a plastic supermarket bag. Not sure that I needed the bag; the alginate is very thick. One pound was enough to cover my hand to just beyond my wrist.
It turned gray/white in about 3 minutes and I was able to pull my hand free. All hair remained on my arm. Filled the form with plaster of Paris and the resulting cast was incredibly detailed.
$15 on Amazon prime.
1lb (454g) Create-A-Mold Alginate Molding Powder by Casting Keepsakes