--- title: "Designer Ben Uyeda shows on YouTube how he grinds river rocks into hotel bowls for under $5 in stone" url: https://badiyaa.com/river-rock-bowls-angle-grinder-silica/ published: 2026-10-16T02:31:00+01:00 modified: 2026-10-16T02:31:00+01:00 section: Lifestyle publisher: Badiyaa --- # Designer Ben Uyeda shows on YouTube how he grinds river rocks into hotel bowls for under $5 in stone HomeMadeModern's tutorial turns 6- to 12-pound river stones into bowls in minutes. Federal guidance says the silica dust from grinding stone needs water or a HEPA vacuum, not just a mask. The stone for one of Ben Uyeda’s carved river-rock bowls costs about $2 to $5. The designer, who posts as HomeMadeModern, buys smooth 6- to 12-pound river stones from a landscape supplier at 35 to 40 cents a pound, then hollows them with an angle grinder, a hammer and a chisel. His tutorial is spreading again this week, two years after he first posted it, and he says he can turn out four or five bowls an hour. The working is simple. At 6 pounds and 35 cents, a stone costs $2.10; at 12 pounds and 40 cents it costs $4.80. Hand-carved stone bowls listed on Etsy start at about $20 for small ones and around $100 for large ones. ## The real cost is in the air, not the rock An angle grinder is a handheld tool that spins a disc at a right angle to the motor. A German firm, Ackermann + Schmitt, introduced the high-speed version in 1954, and it moved from metal shops into home garages once cheaper and cordless models arrived. Two hazards matter when you point one at stone. The first is dust. Natural stone contains crystalline silica, and the federal workplace safety agency, OSHA, says cutting, grinding or crushing rock creates respirable particles at least 100 times smaller than beach sand. Breathing them raises the risk of silicosis, an incurable lung disease, as well as lung cancer, chronic obstructive pulmonary disease and kidney disease. About 2.3 million people in the US are exposed to silica at work, and the legal workplace limit is 50 micrograms per cubic meter of air averaged over an 8-hour shift. The second is the disc. Federal construction rules require a guard strong enough to hold fragments if a wheel shatters, leave no more than 180 degrees of the wheel exposed, and require that wheels be inspected and ring-tested for cracks before they go on. A jammed disc can kick the tool back toward the user, and a study by the National Institute for Occupational Safety and Health measured unloaded grinders at 91 to 103 decibels, loud enough that hearing protection belongs on the list with goggles. ### What federal guidance says to do about the dust - Use water: spraying the cut keeps dust from rising. - If you cannot use water, use a vacuum shroud with a HEPA filter, or both together. - Use local exhaust ventilation where the work is dusty, and an enclosure where one is available. - When cleaning up, do not dry sweep or blow the dust around with compressed air. - Treat a respirator as the last layer, for when the controls above cannot keep levels down. The common mistake is treating an N95 mask as the whole answer. Federal guidance puts respirators last in its order of controls, for use when water, extraction and enclosure cannot keep exposure below the limit. ## What the clip does well, and what it skips Uyeda’s 10-minute video, posted on October 17, 2024, is a sponsored episode tied to a hotel he is building. He says he is carving the bowls for that hotel while traveling around Southern California for materials. The method is efficient. He grinds a flat base first so the bowl will not rock, cuts a grid of straight kerfs into the top, knocks out the small wedges with a chisel, then smooths the hollow with a domed grinding head on an extension shaft. A box of sand holds a round stone steady when a vise will not, and a food-grade mineral oil finish helps the stone resist moisture and wipe clean. Those are good shop habits, and the material is honest: a rock, a blade and an hour. The description links the exact grinder, tile blade, curved grinding wheel, ball-grinder shaft and mineral oil he used, which makes the project easy to copy. That is also the weak point. The tool list in the description includes no dust extraction, water feed or hearing protection, and a viewer copying the parts list would end up with the cutting gear and nothing else. Across a full set of bowls, that dust adds up. If you want a set of six, the stone will run about $13 to $29. Budget for a HEPA shop vacuum, a water bottle for misting the cut, and ear defenders before buying the rocks. ## Further reading - [OSHA: Silica, Crystalline overview](https://www.osha.gov/silica-crystalline) - [CDC/NIOSH: Silica safe work practices](https://www.cdc.gov/niosh/silica/work/index.html) - [OSHA: 1926.303 Abrasive wheels and tools](https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.303) - [Wikipedia: Angle grinder](https://en.wikipedia.org/wiki/Angle_grinder) *Image: Kevstan, CC BY-SA 3.0 via Wikimedia Commons* *This article was produced with AI assistance and reviewed by our Editorial Desk. [How we work](https://badiyaa.com/editorial-policy/).*