This is the used kitchen sand mixer I purchased, to mix foundry sand.
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A Commercial Foundry Sand Mixer
- Thread starter GreenTwin
- Start date
Help Support Home Model Engine Machinist Forum:
I have seen some in this "hobby" invest heavily in some very expensive lathes, mills, and other machining equipment.
I have a very modest Grizzly lathe, mill, and tooling, which I inherited, so no cost.
I have put my hobby money into building a commercial-grade iron foundry, and while that has not been cheap, I probably have less money invested in equipement overall than some of the high-end hobby folks.
The furnace, burner, and miscellaneous equipment were not that expensive.
Commercial mixers on the other hand are really outrageously expensive.
At the time I purchased my large mixer, I had more money than time.
At this point, I have more time than money, and so if I had to do over, I would probably have made a mixer.
Many use modified concrete mixers, and those actually work ok, and are relatively inexpensive.
They are big and bulky, but have a significant mixing capacity, if you need that.
I use resin-bound sand for everything, so I mix the same sand regardless of whether it is for cores or molds.
It is clean, dry commercial foundry sand, so not a problem with anything getting snagged in the mixer.
I did actually take my wife's KitchAide mixer, and I use that for small batches of bound sand.
I had to buy her a new mixer, in order to stay married.
I found a used commercial kitchen mixer, and purchased that.
The shop where I bought it asked if I needed help getting it into the car.
I said "No, I can handle it".
LOL, it took five people from the shop to muscle it into the back seat of my car; total weight I think is in the 300 lb range, which is far heavier than it looked.
My large mixer came with a wire attachment like shown on the right in the photo above, but that was not rigid enough to mix sand, so I made my own paddle.
For my small mixer, I use the attachment shown in the center of your photo.
A few photos of my large mixer, and fabricated paddle.
It does not really look like a heavy mixer, but trust me, it may as well be made from a solid block of iron, and it is every difficult to move even a small amount. The weight does keep it in place on the floor while it is mixing.
I put my molding stuff in a small shed, just to try and keep the sand and grit out of the main shop.
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I have a very modest Grizzly lathe, mill, and tooling, which I inherited, so no cost.
I have put my hobby money into building a commercial-grade iron foundry, and while that has not been cheap, I probably have less money invested in equipement overall than some of the high-end hobby folks.
The furnace, burner, and miscellaneous equipment were not that expensive.
Commercial mixers on the other hand are really outrageously expensive.
At the time I purchased my large mixer, I had more money than time.
At this point, I have more time than money, and so if I had to do over, I would probably have made a mixer.
Many use modified concrete mixers, and those actually work ok, and are relatively inexpensive.
They are big and bulky, but have a significant mixing capacity, if you need that.
I use resin-bound sand for everything, so I mix the same sand regardless of whether it is for cores or molds.
It is clean, dry commercial foundry sand, so not a problem with anything getting snagged in the mixer.
I did actually take my wife's KitchAide mixer, and I use that for small batches of bound sand.
I had to buy her a new mixer, in order to stay married.
I found a used commercial kitchen mixer, and purchased that.
The shop where I bought it asked if I needed help getting it into the car.
I said "No, I can handle it".
LOL, it took five people from the shop to muscle it into the back seat of my car; total weight I think is in the 300 lb range, which is far heavier than it looked.
My large mixer came with a wire attachment like shown on the right in the photo above, but that was not rigid enough to mix sand, so I made my own paddle.
For my small mixer, I use the attachment shown in the center of your photo.
A few photos of my large mixer, and fabricated paddle.
It does not really look like a heavy mixer, but trust me, it may as well be made from a solid block of iron, and it is every difficult to move even a small amount. The weight does keep it in place on the floor while it is mixing.
I put my molding stuff in a small shed, just to try and keep the sand and grit out of the main shop.
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Attachments
Bound sand can be reused, but it has to be ground up, and then the resin burned out.
I don't try to reuse my molds, but I have saved a lot of them, and am considering grinding them up and using them as resin-bound backing sand, and use new resin-bound sand as facing sand (I think a common process in some commercial foundries, especially with Petrobond).
Households are allowed to dispose of bound sand materials (also used in pottery making) in the regular garbage, as long as the quantity is not large every week (I forget the exact poundage, but it is pretty generous). Cured resin is basically plastic-like material, and it is not nearly as toxic as things like insect spray, weed killer, paint, etc., which all goes in the regular trash for households.
And all landfills in this region (perhaps the entire country) must be lined with a heavy waterproof liner, and leachate drains are installed inside the liner, to remove any liquids that drain out of the waste material.
Supposedly mixing resin into ground up re-used non-burned-out resin-bound sand does not make as strong of a mold.
At any rate, I intend to reuse most if not all of my used resin-bound sand, as described above, by using it as backing sand, where the texture and strength are not that critical.
I use OK85 commercial foundry sand, which is a very fine round-grained sand.
This sand is so fine that if you have it in a plastic bag, and you get a pinhole in the bag, the entire contents of the bag will migrate out and onto the floor.
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I don't try to reuse my molds, but I have saved a lot of them, and am considering grinding them up and using them as resin-bound backing sand, and use new resin-bound sand as facing sand (I think a common process in some commercial foundries, especially with Petrobond).
Households are allowed to dispose of bound sand materials (also used in pottery making) in the regular garbage, as long as the quantity is not large every week (I forget the exact poundage, but it is pretty generous). Cured resin is basically plastic-like material, and it is not nearly as toxic as things like insect spray, weed killer, paint, etc., which all goes in the regular trash for households.
And all landfills in this region (perhaps the entire country) must be lined with a heavy waterproof liner, and leachate drains are installed inside the liner, to remove any liquids that drain out of the waste material.
Supposedly mixing resin into ground up re-used non-burned-out resin-bound sand does not make as strong of a mold.
At any rate, I intend to reuse most if not all of my used resin-bound sand, as described above, by using it as backing sand, where the texture and strength are not that critical.
I use OK85 commercial foundry sand, which is a very fine round-grained sand.
This sand is so fine that if you have it in a plastic bag, and you get a pinhole in the bag, the entire contents of the bag will migrate out and onto the floor.
.
I added some shelves on one side of the molding shop, since the bound molds have to be places on a very flat surface after they set, else they will warp a tiny bit; just enough to cause a mold leak, if they don't stay perfectly flat for about 30 minutes after set time.
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I had production found most time natural bonded sand just add water. Work great.
Also tried 4,000 pounds Petorbond sand. It great sand good too use psin oil and alcohol for the catalyst. But just to costly. The natural bonded sand just add water was best price. Easy to mix and no smoke.
Cores I used CO2 type sodiuming silicate. Later I try avoid most cores and machine where was it was lower in cost. The core and molds for one off boiled linseed oil and sand blast sand . Then simple mixer using a ½ drill motor and bucket. Baking was problem but would if time in sun would soon or later setup.
I hope some will help
Dave
