[HN Gopher] Rock Tumbler Instructions
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       Rock Tumbler Instructions
        
       Author : debo_
       Score  : 135 points
       Date   : 2025-10-25 16:32 UTC (6 hours ago)
        
 (HTM) web link (rocktumbler.com)
 (TXT) w3m dump (rocktumbler.com)
        
       | YZF wrote:
       | I had a rock hounding phase in my life ... It was something fun
       | to do with the family and we have a lot of interesting rocks in
       | BC.
       | 
       | I built my own rock tumbler using some wood, hardware store bits,
       | and an old geared DC motor... I also used commercial rock
       | tumblers. Those worked better ;)
       | 
       | It takes a really long time to tumble rocks, you have to go
       | through the grits like a week or two at a time, and they sort of
       | come out without a lot of character. Hand polishing them (with
       | power grinders and polishers) is a lot more satisfying and you
       | can make them into your own. That does require more equipment
       | though.
        
         | debo_ wrote:
         | My first tumbler was built from a lawnmower my dad discarded
         | when I was around 11 years old. I buried it in the forest and
         | topped up the gas whenever I had time. It really did not work
         | at all.
        
           | noman-land wrote:
           | Loved the twist ending.
        
             | DonHopkins wrote:
             | Do not fall into the trap of anthropomorphizing Larry
             | Ellison!
             | 
             | https://news.ycombinator.com/item?id=15886728
        
               | zahlman wrote:
               | What does that have to do with attempts at DIY rock
               | tumblers?
        
               | clort wrote:
               | the lawnmower is the link
        
               | DonHopkins wrote:
               | ...You need to think of Larry Ellison the way you think
               | of a lawnmower.
        
               | zahlman wrote:
               | ... and your thinking is that because someone else
               | mentioned a lawnmower, you should bring up that meme
               | about Ellison, even though it's clearly nothing to do
               | with the OP?
        
               | DonHopkins wrote:
               | Yes, the first thing that pops into my head whenever
               | anyone mentions lawnmowers is Larry Ellison, and the
               | other way around too.
               | 
               | Just like couches and JD Vance.
        
       | pavel_lishin wrote:
       | I have a rock tumbler that I got as a present. It's neat, but
       | this page is right - it takes _a long time_ , and you end up
       | using a lot of grit as well, and it must be done in order. Oh,
       | and did I mention that it's noisy? Definitely not a hobby for ...
       | me.
       | 
       | But! One thing I have found interesting is that you can make your
       | own "sea glass", by breaking wine or beer bottles, and tumbling
       | the big-ish chunks. The thicker the glass, the better, of course.
       | I'm experimenting with just using some sand as the grit material;
       | the glass doesn't come out shiny and smooth, but it definitely
       | wears down the sharp edges.
       | 
       | (And I run the tumbler thing in our detached garage.)
        
         | debo_ wrote:
         | I add ceramic fillers to make sure the barrel is at least 3/4
         | full. It makes very little noise that way; I can't hear it when
         | standing outside the door of the room I'm running it in.
         | 
         | I like the glass idea, that sounds fun.
        
           | dylan604 wrote:
           | > ceramic fillers
           | 
           | Thanks for this tip. I'm planning on buying a friend a
           | tumbler for xmas, and if this works as advertised, I feel
           | this would be a must have as part of the gift.
           | 
           | Edit: of course, TFA mentions this as well for those willing
           | to click the link <facepalm>
        
             | debo_ wrote:
             | It's a long article :)
        
         | Mistletoe wrote:
         | My girlfriend loves sea glass and has a rock tumbler. I think
         | we will try this, thanks!
        
         | zafka wrote:
         | You can pick up Silicon Carbide grit pretty cheap online (
         | impure moissanite ). I have several tumblers, but have yet to
         | finish the process of making polished gems- but it is still on
         | my bucket list :). I have made lots of "sea glass: though. I
         | have taken quite a bit to the local beach ( about 40 miles
         | north of Palm Beach Fl. ) I toss it into the surf, figuring it
         | will make some beachcombers happy. My logic is that once it has
         | been in the ocean a few days, it will actually be sea glass. I
         | would not make that claim for any of the glass that comes
         | straight out of the tumbler though. Next time you visit a craft
         | show and see folks with "Sea glass" Jewelry, note if they have
         | separate displays for "real" sea glass, and man made.
        
       | teiferer wrote:
       | That's cool and all but ... what's the point? What do you do with
       | these rocks afterwords?
        
         | debo_ wrote:
         | I have several children in my life who are going through a
         | shiny objects phase. I ask them to give me rocks that they
         | like, and then I tumble those rocks for them. They really seem
         | to like it.
        
         | photonthug wrote:
         | Most people do this so that they can eat the rocks afterward.
         | They are shiny and very nutritious, and it strengthens the
         | teeth. It's normal for some teeth to break off during this
         | phase, but a) you already have colorful rocks to replace the
         | teeth with, and b) old broken teeth can now be placed inside
         | the tumbler for smoothing. 9/10 geologists agree that
         | unsmoothed teeth that aren't made of rock are the number one
         | cause of oral hygiene problems
        
           | lossyalgo wrote:
           | +1 can confirm. Also the best rock candy is made with actual
           | rocks.
        
             | DonHopkins wrote:
             | You can train the smart ones [1], and even wirelessly
             | remotely control them with a mobile app [2], as long as you
             | restrict yourself to commanding them to do things they were
             | going to do anyway, just like cats.
             | 
             | Kudos to the Stoned Republicans of the High Frontier Panel
             | and The Heritage Foundation for their groundbreaking earth
             | shattering work on Smart Rocks!
             | 
             | [1] Brilliant Pebbles:
             | https://en.wikipedia.org/wiki/Brilliant_Pebbles#Smart_Rocks
             | 
             | >In March 1988, Teller and Wood were able to directly brief
             | President Reagan on the concept, taking the model pebble
             | with them and theatrically hiding it under a black cloth
             | when reporters were allowed to take pictures. Teller
             | reiterated that the price for the system would be on the
             | order of $10 billion.
             | 
             | Photographic proof (not AI generated): https://en.wikipedia
             | .org/wiki/File:Brilliant_Pebbles_present...
             | 
             | [2] Pet Rock Remote Control:
             | https://www.youtube.com/watch?v=SG0FAKkaisg
             | 
             | Featuring my Finger Flicking Pocket PC Pie Menus!
        
           | sumnole wrote:
           | Halite is my favorite. I grind it up and put it in
           | everything.
        
           | hagbard_c wrote:
           | This must be the first true troll to ever land on this site,
           | freshly escaped from Discworld.
           | 
           | For those who don't understand I'd just point at the dietary
           | habits of Discworld trolls.
        
         | jdlshore wrote:
         | People like the way they look and feel, and I imagine they get
         | some satisfaction out of having turned a rough rock into
         | something beautiful. They put them in their house where they
         | can admire them, and others can admire them. Many are probably
         | given away as gifts. Some might be used to create larger works
         | of art, such as earrings or other jewelry.
        
         | j4coh wrote:
         | As best I can tell you can't even properly monetise this or get
         | VC funding. Seems like a waste of effort.
        
           | noir_lord wrote:
           | Indeed spending time on things that bring you pleasure but
           | other people may not understand isn't part of that grind
           | mindset, if you aren't grinding you should be sleeping and
           | honestly if you are sleeping a healthy amount you aren't
           | grinding enough.
           | 
           | Or something - "because I find it enjoyable" is a perfectly
           | self contained reason as long as you aren't hurting anyone
           | else (or yourself).
        
             | conorh wrote:
             | I really appreciate the grinding puns in this comment.
        
             | ternus wrote:
             | > If you are sleeping a healthy amount you aren't grinding
             | enough
             | 
             | Unless you build a soundproof box for your rock tumbling -
             | then you can run it 24/7.
        
           | Nition wrote:
           | Gronk think, did man become so obsess with grindset that even
           | forget like shiny rock? Even word based on grind stone. Once
           | was, whole economy based on like shiny rock! Special ritual,
           | give shiny rock for marry girl. Human like shiny rock seem
           | very basic thing. Gronk wonder... what we become?
        
         | RebeccaTheDev wrote:
         | I mean, it's a hobby? It doesn't necessarily have to have a
         | point other than to enrich your existence.
        
         | steve_adams_86 wrote:
         | My son and I get a kick out of it. For a while he was selling
         | them on the street outside our town home, and that was absurdly
         | lucrative for him. He has made around $200 so far. I'm pretty
         | sure it's because he's cute. In any case, it's just a fun thing
         | to do and experiment with, learn, and explore.
         | 
         | I've also thrown a bunch into an aquarium as 'river stones',
         | because it's illegal to take them from rivers here and buying
         | them is way too expensive. Those are just bland, small pieces
         | of dark granite to simulate the environment the aquarium is
         | modeled after.
        
         | andai wrote:
         | Is shiny!
        
         | sunrunner wrote:
         | No, they're minerals! Jesus teiferer, I've got some geodes
         | coming that are very delicate, alright?
        
         | xpe wrote:
         | After carefully weighing, cataloging, chanting, and valuation,
         | the custom is to skip them into river of their birth. (This is
         | why river rocks are so smooth.)
        
         | ofalkaed wrote:
         | Lots of people use the end result in some other hobby like
         | jewelry or other crafts. The stores here that cater to tourists
         | are filled with things made from/with local tumbled stones,
         | mostly agate. I considered getting one for a mancala set but we
         | have a lot of rocky shoreline and river beds, finding well
         | enough polished stones in the required shape/size is not all
         | the difficult.
        
       | jackbeck wrote:
       | I have strongly negative connotations with rock tumblers. When I
       | was about 8 I saw one in a store and thought it would turn
       | regular rocks into precious stones. One of the biggest
       | disappointments of my childhood.
        
         | JKCalhoun wrote:
         | I hope you didn't buy Sea Monkeys next.
        
           | throwup238 wrote:
           | Or XRay Specs
        
             | Tempat1 wrote:
             | Fun fact: Both were invented by the same guy, Harold Nathan
             | Braunhut.
        
               | JKCalhoun wrote:
               | Wow, that guy is a piece of work.
               | 
               | https://en.wikipedia.org/wiki/Harold_von_Braunhut
        
         | djmips wrote:
         | I was lucky to live in an area with a lot of interesting semi-
         | precious stones that you could just find by looking around.
        
           | jackbeck wrote:
           | I wasn't aware that there were places that had semi-precious
           | stones just lying around. Where are you from?
        
             | ascorbic wrote:
             | Anywhere with granite will have lots of quartz of various
             | types
        
               | t-3 wrote:
               | Yeah, I dug up a bunch of quartz crystals, some granite
               | containng small fossils (tiny clams, small spiral shells
               | etc), and a few pieces of turqoise in the backyard as a
               | kid. How interesting the rocks in your own backyard are
               | depends a lot on the geological history of the area
               | though.
        
         | ternus wrote:
         | The claims made on that kind of hobby tool, in that era, serve
         | as a fantastic argument for truth-in-advertising laws. Looking
         | at you, the perpetual ad for (plans for) time machines and
         | force fields in the back of Boy's Life.
        
       | JKCalhoun wrote:
       | I think I like this post because, simpler things, simpler times.
        
       | kyrofa wrote:
       | Loved this as a kid. But as a parent, even putting it in the
       | garage is just too much noise for my household, haha!
        
       | EvanAnderson wrote:
       | Lots of comments are talking about how loud rock tumbling is. I
       | have an interest and space in my basement but I'm reticent to
       | pull the trigger without knowing if it's going to be intolerably
       | loud upstairs. Does anybody know how many dB the process actually
       | generated?
       | 
       | Edit: Finally got to a PC to do some search-engine investigation
       | and found this: https://rocktumbler.com/tips/how-much-noise-does-
       | a-tumbler-m...
        
         | thangalin wrote:
         | Rock tumbler enclosure, soundproofing box.
        
           | EvanAnderson wrote:
           | I worry about heat dissipation, but maybe that's considered.
           | 
           | When I printed my "underground newspaper" on a dot matrix
           | printer, back in high school, I thought I'd get away with so
           | much printing without my dad knowing by putting a cardboard
           | box over the printer to deaden the sound. It worked until it
           | didn't. Luckily the printer had a thermistor on the printhead
           | and just stopped versus continuing to brainlessly grind until
           | seizing-up.
        
             | japhyr wrote:
             | We had a largish cooler for fishing. I ended up putting a
             | towel in the bottom of the cooler to absorb vibrations,
             | closed the lid over the power cord. I checked the
             | temperature a bunch at first to check for overheating, but
             | it wasn't an issue.
             | 
             | We didn't keep at it long, but that kept the noise from
             | being an issue. It was a slow, messy process and we were
             | too busy to pay attention to it over long periods of time.
        
         | bongodongobob wrote:
         | It's not that bad. Put a box over it with a blanket or two and
         | you'll be fine.
        
         | bcraven wrote:
         | I let Home Assistant turn it on once the house is empty, and
         | then off once someone is home.
        
         | pvankessel wrote:
         | I got this one a few months ago and have been running it in my
         | basement directly under my living room, separated only by the
         | floor and a bit of insulation. Can't hear it at all. It's been
         | working well and it's a fun low-investment hobby. I live on a
         | glacial moraine so there are lots of unique rocks in my
         | backyard, and my son enjoys digging for them.
         | https://a.co/d/4HSnVVX
        
       | jimnotgym wrote:
       | I have favorited this thread. It has the best comments I have
       | read in 10 years of hn.
       | 
       | I want to go and build a tumbler now. I'm imagining it is another
       | good use for an old sewing machine (I hoard a few for projects)
        
         | juris wrote:
         | I'm making one out of a treadmill that I snagged over Covid
         | (and subsequently never used)! Idea is to make a jig to hold
         | the tumbler in place. Maybe make it removable so I can still
         | choose to not use the treadmill.
        
           | ascorbic wrote:
           | You did see how long it takes, right?
        
       | nsxwolf wrote:
       | We had one last year and followed the directions exactly. The
       | stones came out very smooth but cloudy and dull. Not sure what
       | went wrong.
        
         | debo_ wrote:
         | If you want a cheap trick, take the cloudy stones and put them
         | in a clear glass jar with water. They are usually lustrous when
         | wet, and the jar can serve as a decorative item in a bathroom
         | or something. I've thought of coloring the water, too, to see
         | how that turns out.
        
       | sunrunner wrote:
       | I see a missed opportunity to use the domain rocktumblr.com.
        
       | thom wrote:
       | My mum spent much of our youth, upon return from yearly holidays
       | to her small seaside home town, tumbling rocks. We were kinda
       | cluttered people growing up, so among other things (an extensive
       | sci-fi collection, hundreds of kitchen gadgets, every
       | microcomputer under the sun) we always had little piles and
       | containers of beautiful shiny rocks strewn around the place. I
       | never had the patience for the tumbling process, but on every
       | beach I considered it my responsibility to find the most
       | intriguing shapes and colours of rocks, fill my pockets, and
       | bring them home. She died this year. We were supposed to scatter
       | her ashes on that beach but my dad refused for inscrutable
       | reasons. And I have a big pile of boring, dull rocks, that
       | neither my mum, nor the relentless sea, is ever going to
       | transform.
        
         | collingreen wrote:
         | Sorry for your loss. I hope you find good closure when you're
         | ready - your rock collection is a great treasure and might
         | serve as either a memento for you or a surrogate for ashes if
         | you wanted to spread them on your nearby beach. Kind of a nice
         | metaphor for a life well lived; collected from the chaos of the
         | beach, polished up, and eventually returned, hopefully leaving
         | things a little bit better.
        
         | technothrasher wrote:
         | Your mum sounds very much like someone I would have liked.
        
       | 01100011 wrote:
       | Funny, was just thinking about this the other day as my daughter
       | is currently obsessed with rocks. Did some research and.. nah,
       | I'll just buy polished rocks off the jungle store.
       | 
       | A long time ago I had a brief rock-hounding phase and found some
       | cool rocks. Polished them on a friend's polishing setup. That was
       | pretty fun. I'd rather get back into that vs tumbling.
        
         | jglamine wrote:
         | What's the difference between a polisher and a tumbler?
        
           | 01100011 wrote:
           | IIRC the setup my friend had included a diamond wet saw and
           | various polishing and grinding wheels. For instance I used
           | some wax to stick a rock on the end of a stick and shaped it
           | into a cabochon and, using the various polishing wheels, got
           | it to shine.
           | 
           | A tumbler is just a bunch of rocks and polish bouncing around
           | for a week and you never know what you'll get.
        
       | orliesaurus wrote:
       | I've been tumbling rocks with my kids for about a year now. Two
       | tips that made it actually sustainable: (1) ceramic media is a
       | must-have, not optional - cuts the noise by 80% and you can run
       | it indoors, and (2) skip the "perfect rocks" hunt and just tumble
       | broken glass bottles instead. Takes 2-3 weeks vs 2-3 months,
       | looks amazing, and my kids can actually see results before they
       | lose interest. We keep a jar of the sea glass pieces on the
       | kitchen counter and it's become a surprisingly nice conversation
       | starter when guests visit.
        
       | fainpul wrote:
       | Similar tumblers (just a little bigger) are used to deburr and
       | finish metal parts after fabrication.
       | 
       | https://www.enginebuildermag.com/2020/10/parts-tumblers/
        
         | mikestew wrote:
         | Or polish brass bullet casings for those that reload their own
         | ammo.
        
       | gclawes wrote:
       | Small pieces of the old world still exist, if you can find them
        
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       (page generated 2025-10-25 23:00 UTC)