Very fast and effective way to crush bentonite

Discussion in 'Sand Mullers' started by Pedro Ruela, Jul 27, 2020.

  1. Pedro Ruela

    Pedro Ruela Copper

    Hello everyone.
    In my never ending quest to find bentonite in Portugal, appart from a beauty shop for 20€ 2 pounds, I resorted to granulated bentonite used for Cat litter. 2€ 8 pounds :).
    After going Daniel San, wax off wax on with a 6 pound slice of round steel, for a few hours, my back started to complain, and I only crushed about 1 pound. I decided to pour the entire content on top of a 1/4 inch steel plate and run a cylinder back an forth over it. It worked like a charm, and crushed 7 pounds in 90 seconds to a very fine powder, and nearly no effort. I hope this helps someone with the same problem.

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  2. rocco

    rocco Silver

    In North America, very finely powdered Bentonite is commonly available at pottery supply houses, is that not so in Portugal as well? As an example of the sort of place I'm talking about, here's where I got my Bentonite.
  3. Tobho Mott

    Tobho Mott Silver Banner Member

    Wow, a ride-on muller! :D Good idea.

    dtsh and Pedro Ruela like this.
  4. Pedro Ruela

    Pedro Ruela Copper

    Hadn't gone down that road (pottery supply shops)
    Now I did and found one that sells this quik gel A High yield Bentonite, would this do? Aldo Cat litter for 2€ 8 pounds and a cylinder it is hard to beat :).
    I did find a calcium carbonate fine powder supplier, 80 pounds bag 35€, which should last me a lifetime.

    By the way, maybe you can help me, every time I pour something onto sand, I need to add bentonite, every time? (besides moisting the sand and sifting it) before doing another mold? I had 4 pretty good molds and then 50 hours of hell, then I started thinking about it :(.

    Attached Files:

  5. Tobho Mott

    Tobho Mott Silver Banner Member

    I used a combination of Quik-gel (sodium bentonite) and expensive cosmetics grade calcium bentonite ordered online to make my sand. You can just use sodium bentonite if that's what you can get.

    Edit - once you get your sand right, you shouldn't have to add more clay I don't think. At least not often.

    Last edited: Jul 27, 2020
  6. Bentonites are used in a wide range of industrial applications including well drilling, water purification, reservoir sealing, pottery (already mentioned above) etc. Man, you'd think there would be some somewhere near you.

    Foundry use is probably the smallest niche for its application. Using both calcium and sodium bentonite together in green sand is advantageous. I did get along for a couple years with just calcium bentonite, but my sand worked better when (after encouragement from folks on HomeFoundry) I added in some sodium bentonite.

    HT1 likes this.
  7. FishbonzWV

    FishbonzWV Silver

    Powdered Bentonite is also used as a feed additive for cattle. It's also used to patch leaking ponds.
    I bought a 25Kg bag from a farmers feed store. I thought that would be a lifetime supply but went through a lot of it before changing to Petrobond.
  8. HT1

    HT1 Silver

    clay additions depend on how much sand you are burningin : cast Fe, Maybe 10% half that in Brass Bronze, prettty much zero in aluminum. burnt sand is the truely burnt stuff stuck to the part, not just the Blackening of the Sand . in short little to no clay additives unless you are doing cast Fe, now other additives especially cereals run a little higher ,

    this is why facing sands are such a good idea. you can get perfect sand next to your casting for appearance, hot strength and permiability , backed by more questionable sand which is really there as support and insulation permiability is delt with with proper venting

    V/r HT1
  9. Billy Elmore

    Billy Elmore Silver

    You just need to replace what was burnt out. After the initial addition you can pretty much keep using it without adding any or just very little unless you are pouring big heavy and hot parts that burn it out faster.
    Pedro Ruela likes this.

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