How do you re-purpose green sand?

Discussion in 'Sand Mullers' started by OMM, May 30, 2020.

  1. OMM

    OMM Silver Banner Member

    I do not have a sand Muller, (and I do not want to make one or buy one). Is there a simple way to use a drill press? (Sensitive drill press). I have made up my own green sand. Just using kitty litter, play sand and a little bit of water soluble oil. (I've also been playing with some oil based construction Clay with some small fires). But the green sand seems to be holding a good finish on aluminum so far. But…, It really burns and leaves big clumps. I've been pulling the big clumps aside, not sure what to do with them.

    Repurpose, or get rid of. What do you guys do?
  2. FishbonzWV

    FishbonzWV Silver Banner Member

  3. Petee716

    Petee716 Silver Banner Member

    Whether the mixture is usable again or not remains to be seen. There's no telling what your soluble oil has become after burning, or the kitty litter for that matter, because they have been basically subjected to an uncontrolled chemical reaction. Not to mention the unknown composition of the smoke coming out of your mold. Crush it back up and try it if you're so inclined. Personally I'd throw it out and get the right stuff. The three items you need are neither rare nor expensive.

    Whatever you might come up with as a mixer driven by your drill press, it's not going to do your drillpress any favors. You don't really need a muller to mix basic greensand. Videos of our fellow casters in Africa and the subcontinent demonstrate that, among others, but I doubt a single one of them would turn down a muller. You could get by with a shovel and a tarp and some stomping but you certainly have the means and know-how to build one. Google VonTorne muller. I built one and it works great for greensand.

    You don't need a lecture from me but after all of the time, effort, money, and technical expertise you've brought to your preparations so far I'm surprised you would limit yourself in this way, not by your muller decision but your choice to use stuff you have around the house instead of the right materials. I know you like to paddle your own canoe, but jeez, give yourself a break.

    Last edited: May 31, 2020
  4. dtsh

    dtsh Silver Banner Member

    I use a homemade greensand too, but I'm with Petee716 about this particular mix in that you have a lot of variables in there and I'm not sure what you were shooting for. All that aside, I think an important measure is volume; I have about 75-100lbs of greensand total, a volume I think many here would consume and find themselves short when making molds, but it fits my process fine. I haven't needed a muller yet becasue my volume is so small I can easily process it by hand with a little effort.

    I'm not sure how you would repurpose it as the composition is questionable now.
  5. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    There was a fella either here or at AA that just aerated his green sand with a drywall paddle mounted in potent 1/2" drill, mixing in a 5-gal bucket held between his feet. He did 10-15 lb batches at a time and just a couple minutes a batch. In 15 minutes he had 100lbs of nice fluffy green sand. It's not mulling per say but Ole Foundryman has a somewhat more sophisticated aerator for his green sand with great result.

    OMM likes this.
  6. OMM

    OMM Silver Banner Member

    Thanks. With A little looking, I found One of his videos doing a break down and rebuild.
    Last edited: May 31, 2020
  7. Tobho Mott

    Tobho Mott Silver Banner Member

    What is the oil and oil based clay supposed to do? I'm really not sure what effect adding those to greensand might have.

    Before I built my muller, this is how I got my bentonite, sand, and water (+ Smelko Foundry Products Ltd.'s "other carbonaceous additives") ready for molding:

  8. OMM

    OMM Silver Banner Member

    Making my own green sand is just for fun. Just trying different household remedies. Smelko is not too far for me... When I'm ready for 100 pounds, I'll probably just go there.
  9. Tobho Mott

    Tobho Mott Silver Banner Member

    Their sand is great, I started with 100# but now I save it for facing. It gives a great finish when I don't overheat the melt, or screw up the gating, or mull it too wet...

  10. OMM

    OMM Silver Banner Member

    Well, after watching many videos on Martin's channel, (this guy blows me away) I think I'm going to push forward with making a small drill press mixer. If it works or fails, I don't care too much.

    I'm going to make it bit smaller than Martin's mixer. I'm going to add a few things that I think might be improvements and change a few things that he would consider detrimental. My thought process with using a drill press and a simple attachment does not take up a lot of space in the shop!

    So here we go.... I'm only using what I have in stock (offcuts). I will have to purchase some screws and possibly modify their lengths. I did design everything around what I have without spending money.

    I have a piece of 3/4" Dia. hot rolled steel for the drive bar. I have a small piece of 1.750" dia. for the mixer end. And I do have some 4" schedule 40 pipe. And a 3/4 to 1" bronze bushing. I also have a small piece of 3/4 x 2" HRS for the bushing alignment.... so, manly 4 pieces.

    I only plan on using 5/16 screws with enough spacing to go to 3/8" if need be,

    So today I bored out and laid out the beater attachment. (With Drawing). Sorry about the chicken scratch drawing, but this is how I work.

    The beater will have 8 screws on the top level and shifted at 22 1/2° for the 8 screws for bottom level. The screws on each level will be 45° offset with a 22 1/2° offset from the previous level. If that makes sense.

    Last edited: Jun 23, 2020
  11. OMM

    OMM Silver Banner Member

    Today I drilled and tapped for the 16 screws in the beater head. Each screw will clamp as a grub screw the drive bar.

  12. Tobho Mott

    Tobho Mott Silver Banner Member

    Looks good to me. :D

    I stumbled across a YT channel recently where another guy is building an Olfoundryman sand fluffer. Here's his latest update, if you're interested:

    OMM likes this.
  13. OMM

    OMM Silver Banner Member

    Thanks Jeff. I watched a few of his videos.

    Part number two fell off the 3-D printer tonight (Bridgeport milling machine).


  14. OMM

    OMM Silver Banner Member

    Part three is just a piece of 3/4” x 2” Hot rolled steel that I cut and machined 6.750” long. I laid out the shape I wanted to machine it to, Then I started cutting and drilling.




    Then I finally finished with a piece that was pretty darn close to my original design. So, now it’s up on the grinder.

    Last edited: Jun 29, 2020
  15. OMM

    OMM Silver Banner Member

    Right now, the pieces are all completed. I’ve done a dry fit. All the screws have had purple Loctite (Service removable) applied. (I do like using blue and purple Loctite in situations like this.)

    Tomorrow when the Loctite is dry, I’ll do an assembly. AND Yes Jason I said, an assembly not an ass-embly;). But, if it doesn’t work, I’ll spray paint it gold and send it out to Our fearless leader to put up on his Trophy wall (Maybe alongside your BP). This design would really help keep things moving. LOL. (at least the screws are the right colour already.)

    The mid evil enema might have her maiden voyage tomorrow. I do still have to transfer the grease nipple through to the bronze bushing.



    Last edited: Jun 30, 2020 at 10:08 PM
    Jason likes this.
  16. Jason

    Jason Gold Banner Member

    Damn I want a surface grinder. Saw one recently in Dallas, but didn't dare ask my wife if I could add it to the garage. I'll eventually get one, but I've got bigger fish to fry right now.:(
  17. OMM

    OMM Silver Banner Member

    Personally you don't want to surface grinder unless you get it for a song and dance (or you can get a nice little brown and sharp 6×12 fully set up).
    I got mine for $200 Canadian but it was 550 V.
    I had to buy a magnet for it and that cost me $350 Canadian off of Kijiji. 6×18. new, $2000.
    I bought a Haring fixture for $350 Canadian off of Kijiji. But new they ring in at $2500
    I bought two new grinding wheels that cost me $250 Canadian. But I have dozens and dozens of smaller ones.

    I already owned a grinding vice, a sine chuck, gauge blocks, gauge pins and a cylindrical grinder. This rabbit hole gets really deep fast.

    My shop is set up for 120 V single phase, 240 V single phase, 240 V three phase, 600 V three phase. When you are set up like I am (,which is not cheap) it opens a world of auctions not thought of by the single phase office boys.
    Last edited: Jun 30, 2020 at 10:44 PM
  18. Melterskelter

    Melterskelter Silver

    I love my grinder. I use it for general surface grinding tasks, but more often for lathe and milling machine tool sharpening. A decent diamond wheel will convert cheap crappy brazed-on carbide cutters into good performing tools. It takes only a minute or two to grind a decent edge onto them. I have also made a variety of tools for my tools like arbors for the grinder and lathe tools as well with it. In summary, a handy and useful tool. A single 46 grit aloe wheel and a diamond wheel are enough for a starter set. Go to websites like practicalmachinist and read a bunch of threads which cover a lot of the basics and more if you want a source of easily available basic operational info.

    Jason likes this.
  19. OMM

    OMM Silver Banner Member

    Assembly went together seamlessly. I didn’t get a chance to run it. But here’s a short video on the assembly and lube.

    Tobho Mott likes this.
  20. Petee716

    Petee716 Silver Banner Member

    Oy, make sure you roll up your sleeves!

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