How to Make a Free Concrete Mixer

The authors homemade concrete mixer

Del Germyn

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.

Try it.