MIXING IN A BUCKET, WITH A SINGLE OR DOUBLE HELIX UNIT OR A VERTICAL SHAFT MIXER, SUCH AS AN IMER
QUESTION: Does this mix well using a handheld mixer?
When you first add the entire amount of water, it creates different size balls, and you'll think it's over, DO NOT ADD MORE WATER. You will see why when you add the sp and with in minutes it turns into pancake batter.
Direct answer is if your using a full bucket kit, split it in have. So with a single blade hand held mixer, I would not try mixing more than 25 pounds. I've done an entire bucket with a double helix hand held but it's simular to mixing a Buddy Rhodes original mix.
That being said with two buckets you can easily, once mixed, pour everything into one bucket, scrape off any unmixed powder, pour that into the emptied bucket and spin it up as to guarantee no un mixed product.
QUESTION: How about an Imer or simular vertical shaft mixer?
When mixing more than 30 lbs. hold back 25% of the dry mix weight, add ALL the water, mix until fluid then add remaining mix and blend.
Although not manditory, this is the preferred method of mixing, especially for larger pours. I have found that when you have finished mixing everything and you open the bottom door/gate to discharge that there is always a little bit of trapped, unmixed powder that rest in the little indentation/recess the resides just above the sliding round door on the bottom of the Imers. Because of this it is mandatory that one "BURNS" several half buckets. By "BURN" I simply mean discharging a half bucket out the bottom and then pour it back in the top until you see no evidence of unmixed powered coming out. Not doing this has burned me twice by causing anomalies on the finished surface due to just a little bit of none mixed powder.***ALWAYS keep your mixer running until you are completly finished, this stops the polymer from skimming .