jamesp
Cave Dweller
Member since October 2012
Posts: 36,178
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Post by jamesp on Jan 5, 2018 5:23:40 GMT -5
I need SiC 60 for rolling glass gently in a rotary to remove bruises on coarse tumbled glass. Using a 60 and 220 mesh lab screen with associated catchment pan and a vibratory tumbler for a shaker. The vibe has the ability to shake hard enough to screen such fine particles. The screen(s) and the catchment pan will be held down on top of the vibe hopper by hand with broad range bulk grit in top most screen pan. Needing about 3 cups of SiC 60 and 1 cup of SiC 220 for particular batch. Screens can be stacked to collect different sizes. No rocket science here. SiC 60 mesh You can take siC 30 or 46 and grind your own smaller sizes by rubbing two plates of steel by hand with the 30-46 between them. No different than what the manufacturers are doing, just smaller scale. Probably not going to grind aluminum oxide, it is much tougher(not harder).
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Post by toiv0 on Jan 5, 2018 10:11:33 GMT -5
Putting the screens on the vbe tumbler a great idea. Our stack of sieve are 6 high. 10..18...35...60...100.270...anything below 270 we consider silt and clay. These special sizes for golf course industry. Sand and gravel just a little different sizes. In the lab we have a shaker at gives it a tap about every 10 sec. We shake by hand and tap the top of the stack and rotate screen about every 10 sec for 5 min. Hand vs lab is about 100 percent accurate on the 10..18..35...60 and a few percent off on dinner grade.
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Post by toiv0 on Jan 5, 2018 10:18:21 GMT -5
So question what is the screen size above the 60. Let's say a 35 screen. So sitting on the 60 is approx 35 grit to 60. Any thing below 60 screen will be 60 minus unless you have let's say the 100 screen below. Your product would be 100 to 60 mesh. That why a straight gradation is so expensive. To get a straight 60 mesh you would need a different classifier.
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Post by toiv0 on Jan 5, 2018 10:29:36 GMT -5
We make sand blasting media and we heat to remove all moisture ( which is what you should do before screening) (in the field pie pan and camp stove wait until cool or you will melt solder on brass screens)first then air classify by weight.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,178
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Post by jamesp on Jan 5, 2018 10:35:39 GMT -5
So question what is the screen size above the 60. Let's say a 35 screen. So sitting on the 60 is approx 35 grit to 60. Any thing below 60 screen will be 60 minus unless you have let's say the 100 screen below. Your product would be 100 to 60 mesh. That why a straight gradation is so expensive. To get a straight 60 mesh you would need a different classifier. I found a set of lab screens in junkyard Billy. Even the old shaker was there. Paid nothing for the screens. Got 10-16-46-60-80-100 screens. It helps to have the vibe shake the screens 60-80-100. Abrasive is allowed to be sold deceptively with size variations, I think this chart is acceptable sizes for deception lol. Take 80 grit for instance, it can vary in size from a true size of 165 to a high of 292(52 grit) to a low of 102(120 grit) and not a damn thing you can do about it. Lest you want to reach deep in wallet and pay for true 80 grit. Cost increases exponential. Like you said, different classifier screen - 81 and 79 mesh ? Chart of allowable variation for claimed size
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notjustone
spending too much on rocks
Member since January 2017
Posts: 426
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Post by notjustone on Jan 5, 2018 12:35:33 GMT -5
hmm I wonder how long the screens will last vibing sic through them.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,178
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Post by jamesp on Jan 9, 2018 23:08:59 GMT -5
hmm I wonder how long the screens will last vibing sic through them. If you don't let it pile up too deep it should help prevent wear. Gravel screens do #2#4#5#7#9#11 etc gravel. But they have thousands of pounds of rocks on them with high powered agitators shaking them. Wear out quick. Most quarry's will load your pick up truck with worn out gravel screens. They are woven wire. Easier to fill a gallon bucket w/mixed and set it on the vibe. Fine stuff goes to bottom, coarse to top. Does it quick. Sic 30 on top, ~Sic 60 on bottom. Separated in seconds pushed down on a vibe. Easy and fast. Takes a while to screen 4 cups of 60 using a screen. Seconds in a bucket and works wet or dry. Plenty accurate for tumbling.
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