Aggregate in a masonry cement mixer

[caver]

I picked up a used mixer a few years ago where the U shaped tub is stationary and a shaft goes through the tub with paddles attached.
Designed for cement not concrete since the paddles run close to the edge where they will pinch aggregate between the walls. Anyone ever try modifying the paddles so you can mix concrete and did it work worth a hoot?
It's like these units only mines an old Goldblatt unit.

Crown Mortar Mixers

 

[dfkrug]

Yeah, that's a tough problem. A mortar mixer like you have will do poorly with concrete. You
might consider using pea stone aggregate, but then you can not make as strong concrete. Is
your paddle-to-drum clearance less than 1/2"? If you do try it with bigger aggregate, then
go high on the Portland and water for more lubrication. It may not work at all. You really
need a rotating drum for concrete.

I ran into the converse of your problem, mixing stucco with a concrete mixer. That is like
sticky mortar and it would rather stick to the paddles than go through them. The answer was
only doing large quantities (1/4 cy) and adding liquid first.

Good luck.

 

[Stimw]

They sell a masons mix that will work in mortar mixers. It has crushed stones in it and will work.
Most mixers have the rubbers worn out anyway which gives enough clearance for the small stones.
HF sells the electric concrete mixers (tumble type) for under $200. on sale.

 

[breadtrk]

Before you trim them down, think about the extra weight the rock will have and how long you expect it to last. There is also the motor to think about.

This is one of those time when you need the right tool for the job, unless it is for a single use deal then go for it.

 

[Larry Caldwell]

You can replace the rubber paddles with steel vanes that clear the walls. It turns the mortar mixer into a concrete mixer. If you need to mix mortar, just put the rubber ones back in.

 

[TnAndy]

I've used mine several times for mixing up to a couple dozen bags of Quickcrete (bagged concrete type mix) for small pours. Occasionally a stone will get caught between the paddle and the barrel, but not too often. If it does, I simply take it out of gear (mine has a lever to engage the motor belt to the paddle gear), and put it back in....it always clears it and rolls on. If it's just a 'once in a while' thing, I wouldn't bother modifying the machine.

 

[dfkrug]

I've used mine several times for mixing up to a couple dozen bags of Quickcrete
(bagged concrete type mix) for small pours.

Yeah, that's pea stone aggregate (3/8"). If you try 3/4" conventional concrete, you are really going to
jamb up. Of course, I have never tried that personally in a mortar mixer.

 

[caver]

I was over at my place yesterday and forgot to look at the mixer. I can't remember if I can adjust my paddles out.