Post by chaosdsm on Apr 26, 2024 19:15:10 GMT -5
So, I've been looking at cheaper alternatives for tumbling grits. In this thread I'll only be referencing stage 1 grits and pricing is to my house including tax & shipping as applicable.
Silicon Carbide (or SiC) @ 9.5 Mohs is great for really hard rocks, and probably the best option for rocks over 8.5 Mohs, but shouldn't be used on anything too soft. It's really too hard for anything under Mohs 7 unless you need some very aggressive cut in the first stage. Every online company I've found wants to charge more for shipping than for the actual product in the bulk bags. I have an industrial mine & mill supply store near me where I can buy it in store. Best price per 50lb is about $189 locally for 60/90 grit.
1> Aluminum Oxide (or AO) is marginally softer @ 9.0 Mohs, and typically half the cost of SiC, but still very hard for soft rocks. Best price per 50lb is about $85 for 60 grit
2> Garnet: 7.0 to 8.5 Mohs depending on variety of garnet, it may be a better option for some of the softer rocks. Best price per 55lb is about $65 for 30/60 grit.
3> Coal Slag: 6-6.5 Mohs This stuff can often be picked up quite cheaply. With its relatively soft nature, this may be an ideal stage 1 grit for Labradorite, Obsidian, and other softer stones. Unlike the first three (including SiC), it doesn't fracture into new sharp (but smaller) abrasives, instead it crumbles as is considered non-recoverable. I have two 50lb unopened bags of 60 grit that I bought for $7 per bag, but current pricing is about $15 per 50lb bag.
I've used all the above in sandblasting with great results. I've of course use SiC in stage 1 & 2 tumbling, and I currently have a batch of Labradorite running with Coal Slag just to see how it does.
4> Sand: common washed play sand 6 Mohs. Widely available and cheap, but you have to be sure to get washed and filtered sand, and do not run a dry tumble with it. Sand will break more like Garnet, AO, & SiC than how coal slag breaks, but is also a non-recoverable product. I'm thinking that sand may be an ideal media for tumbling shells and other delicate materials as there are not a lot of sharp edges unlike the other materials listed. Best price per 50lb = $5 typically 60 to 120 grit depending on where it was processed....
5> Superoxalloy: 7-8 Mohs. I've been sandblasting stuff for a few years, but this one is new to me. Superoxalloy is an engineered alloy of oxide minerals that's created through a process of controlled formulation and tempering, which involves high heat and rapid cooling. This process creates non-crystalline particles that are resistant to breakage under high-speed mechanical impact. I've found 2 varieties of this product, one called EpiX, available as 60 or 80 grit. Manufacturer claims it can be reused 8 to 15 times in sandblasting. Other variety is called KinetiX, available as 36 or 46 grit & is supposed to be reusable up to 6 times in sandblasting. EpiX is about $85 per 50lb bag, KinetiX is about $60 per 50lb bag.
I may try play sand in a vibratory with sea shells.
I am intrigued with the Superoxalloy, about the same price as Garnet, and supposedly resists breakage in sandblasting, might work well for tumbling. I'm seriously considering buying a bag next payday!
Anyone use any other alternative abrasives???
Silicon Carbide (or SiC) @ 9.5 Mohs is great for really hard rocks, and probably the best option for rocks over 8.5 Mohs, but shouldn't be used on anything too soft. It's really too hard for anything under Mohs 7 unless you need some very aggressive cut in the first stage. Every online company I've found wants to charge more for shipping than for the actual product in the bulk bags. I have an industrial mine & mill supply store near me where I can buy it in store. Best price per 50lb is about $189 locally for 60/90 grit.
1> Aluminum Oxide (or AO) is marginally softer @ 9.0 Mohs, and typically half the cost of SiC, but still very hard for soft rocks. Best price per 50lb is about $85 for 60 grit
2> Garnet: 7.0 to 8.5 Mohs depending on variety of garnet, it may be a better option for some of the softer rocks. Best price per 55lb is about $65 for 30/60 grit.
3> Coal Slag: 6-6.5 Mohs This stuff can often be picked up quite cheaply. With its relatively soft nature, this may be an ideal stage 1 grit for Labradorite, Obsidian, and other softer stones. Unlike the first three (including SiC), it doesn't fracture into new sharp (but smaller) abrasives, instead it crumbles as is considered non-recoverable. I have two 50lb unopened bags of 60 grit that I bought for $7 per bag, but current pricing is about $15 per 50lb bag.
I've used all the above in sandblasting with great results. I've of course use SiC in stage 1 & 2 tumbling, and I currently have a batch of Labradorite running with Coal Slag just to see how it does.
4> Sand: common washed play sand 6 Mohs. Widely available and cheap, but you have to be sure to get washed and filtered sand, and do not run a dry tumble with it. Sand will break more like Garnet, AO, & SiC than how coal slag breaks, but is also a non-recoverable product. I'm thinking that sand may be an ideal media for tumbling shells and other delicate materials as there are not a lot of sharp edges unlike the other materials listed. Best price per 50lb = $5 typically 60 to 120 grit depending on where it was processed....
5> Superoxalloy: 7-8 Mohs. I've been sandblasting stuff for a few years, but this one is new to me. Superoxalloy is an engineered alloy of oxide minerals that's created through a process of controlled formulation and tempering, which involves high heat and rapid cooling. This process creates non-crystalline particles that are resistant to breakage under high-speed mechanical impact. I've found 2 varieties of this product, one called EpiX, available as 60 or 80 grit. Manufacturer claims it can be reused 8 to 15 times in sandblasting. Other variety is called KinetiX, available as 36 or 46 grit & is supposed to be reusable up to 6 times in sandblasting. EpiX is about $85 per 50lb bag, KinetiX is about $60 per 50lb bag.
I may try play sand in a vibratory with sea shells.
I am intrigued with the Superoxalloy, about the same price as Garnet, and supposedly resists breakage in sandblasting, might work well for tumbling. I'm seriously considering buying a bag next payday!
Anyone use any other alternative abrasives???