A lot of people (myself included) are a little lazy when it comes to mixing their concrete/hypertufa/etc. This generally results in a poor mix that will not cure properly.
I found an easy solution to this when I was looking around for an easy to make mixer. I was staying in a hotel and there was some construction work going on next door.
They where not using concrete, plaster or hypertufa. The where mixing stucco. I was walking through the parking lot and as I passed the machine that they where using I glanced into it. There was not much mortar left and I could see the mixing mechanism.
In the bottom of the “V” shaped container there was an auger, it was slowly turning and this did all the mixing.
A week or two later I was mixing some hypertufa in a 5 gallon bucket and thought about the auger.
I decided to play with the idea a bit. I went to a wrecker’s yard and picked up an old coil spring from a car. (I don’t know what kind of car, but the spring is about 3 1/2″ outside diameter). They gave it to me for nothing.
I came to my shop with this and found a piece of 7/16″ round bar about 2 ft. long. I welded a piece of 1/2″ flat bar across the top of the coil spring and then welded the round bar onto this as close to the center as I could guess.
Then I cut the spring down to 3 coils.
I put this in my 1/2″ electric drill and set out to mix some concrete. It was not a huge success, but I knew I was onto something. I cut the spring down to about 1 1/2 coils and went back to my bucket.
It worked! It worked great. Tip the bucket a little and run the drill fairly slow. You will discover the correct combination in a minute or two.
One thing I will say is be sure you have a fairly decent drill. The battery ones will not cut it. They will do maybe one bucket full before the smoke appears!! (guess how I know) I got my drill at a garage sale for $5.00. It is big and heavy and loves its new job. If I am passing a garage sale and think of it I am always looking for a backup. I have 2 so far.
I will never mix by hand again, unless it is only a couple of cupfuls for a small test.
This does a way better job than hand mixing in less time with less effort. The concrete or hypertufa is more consistent and seems to cure more evenly.