Another cement mixer muller

Discussion in 'Sand Mullers' started by Melterskelter, Mar 25, 2018.

  1. Melterskelter

    Melterskelter Gold Banner Member

    This problem seemed to begin after running a few hundred pounds of petro through the muller over two or three sessions. It’s oiliness and heavy consistency may encourage sliding of the sand on the floor of the muller AND polish the floor as well. Interesting to know I’m not the Lone Ranger on this problem. I do think scuffing the floor and wheel will keep it at bay. Thanks for letting me know. Too bad the traction tape did not hold up, Pete, as that seems like a clever fix.

    Denis
     
    Last edited: Mar 11, 2021
  2. FishbonzWV

    FishbonzWV Silver Banner Member

    I have the same problem with the unmodified HF mixer. The greensand kept a little surface rust on it. PB shines it up. I have to give the rock a little nudge every now and then to keep it tumbling.
     
  3. Tobho Mott

    Tobho Mott Gold Banner Member

    When I was navigating through switching from mulling greensand to petrobond in a cement mixer muller, HT1 suggested I mull the sand while it's hot and avoid overloading the muller. I wasn't having sliding sand problems, it was hard patches of compressed sand stuck to the wear plate jamming the pushed wheel so that it had to bounce over them. But after (just) a dozen or so pours it does seem like the muller generally has a much easier time turning the sand over and rolling over it smoothly while the sand is still hot and soft.

    By the time I got my PB, my greensand had just about already put a mirror shine on the donut of the wear plate that the wheel passes over... Guess I better keep an eye out for sliding sand!

    Jeff
     
  4. Billy Elmore

    Billy Elmore Silver

    I dont have that issue with mine...it doesnt get used enough to ever get any wear on it.LMAO Mine is much more complicated than most of the ones I see on here though. A hollowed out cement mixer with a huge pinion gear rolling around smashing the sand. It actually worked much better than I anticipated so I never finished the build I started on a typical one.LOL
     
  5. Melterskelter

    Melterskelter Gold Banner Member

    Earlier I mentioned adding a sand deflector in front of my muller wheel and I had mentioned scuffing the wheel to aid rolling action. Today I removed the wheel from the muller and welded on the dflector. While the wheel was so accessible, I decided to hit it with the angle grinder a bit more. Here are a couple pics---not particularly pretty but pretty functional.

    Wheel Deflector.JPG Wheel Tread.JPG

    Denis
     
  6. Melterskelter

    Melterskelter Gold Banner Member

    Let it Rust!

    I have been trying a "natural" texturing method for the wheel and floor of the muller---rust. It is working very very well. Rather than reflexively cleaning all the sand out of the muller at the end of a session, I have been shoveling a third of a bucket of green sand and then adding enough water to make it pretty wet. That is significantly wetter than you would want to get the sand for molding. I then spread it more or less evenly over the floor and mound a bit up around the wheel. That does the trick. In my well-used green sand there must be some residual chemicals (acids?) left over from the heat and coal interaction so that the sand really promotes rusting. That rust provides excellent traction to the floor and wheel of the muller so that sliding of sand under the wheel and consequent stalling of the rotation of the wheel does not occur no matter how overloaded the muller is. So, now I have an excuse to be sloppy with the muller. What's not to like about that?

    Denis
     
    Billy Elmore and Tobho Mott like this.

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