I’ve got a new hobby – how can you live 2 mins from a beautiful natural stone beach and not tumble and polish your own stones? So last month I invested in a stone tumbler, just a small one, it is easy to use and my first batch of stones were not too shabby! Since my first batch I have picked up some tips, so the next batch was even better – BUT… There is one drawback. It is quite noisy inside the house.
First I tried putting it in a cardboard box with towels piled on top to dampen the sound – not bad… But you had to leave a gap as the motor gets hot. Still a bit noisy. So the solution was to run it in the day and turn it off at night as it rumbles a bit and you know how sound has a way of being louder at night when everything’s quiet, mind you, my neighbour next door is quite deaf so no complaints as yet!
So, what could we do about the noise? I have no means of putting it outside, no shed, so it has to be inside. The machine takes two – one and half pound barrels – so you could just run one which is not so noisy but then thats a waste of energy when you could be running two simultaneously until one day my hubby had a brainwave…
We’ve got a fan assisted cooler box, the ones you put cold or frozen food in when you’re travelling in your car, plugs into the 12volt cigarette thingy, he had the idea of putting the tumbler inside and closing the lid to soundproof it and at the same time the fan runs in the top of the cool box keeping the Motor cool. Spiffing idea! Just need a 12v adapter power supply so we can plug the cool box into the wall. Taking a risk we ordered a power supply on eBay £7 in all, with a soldering iron he melted a place to put the lead of the plug, not too big or noise could escape through the hole and hubby wired up the power supply (great handyman)
So today was the big day. I had one barrel ready to go, lowered it in and we switched on. Well, what an amazing improvement! you hardly heard anything apart from the gentle fan sound. Time to add an extra barrel. That was an improvement too – considering I couldn’t run two barrels before because of the noise. So there we have it… A great solution to a noisy problem and it kept the motor cool.

Here’s my tips on stone tumbling, mainly serpentine stone, which is a softer stone compared to some others – the hardness of the stone you’re tumbling is worth checking online. (photo below: Should read fan INTAKE not output)

1. Be quite selective about your stones. Any with cracks, or a crazed top will not come out so well, if you’re tumbling stones from the beach then the sea has done a lot of tumbling for you. Unless the stone is amazing, try to get ones that are well shaped or the shape you require for your project. Try to search for stones when the stones are wet, this gives you an idea of what colours will come out once the stone is polished (serpentine shows up better when wet)
2. Don’t tumble different hardness of stone together, some stones are softer and can get damaged with harder stone placed with them. I tend to tumble serpentine on it’s own.
3. If the stones are well tumbled already by the sea, you might only need to do two stages of tumbling. I use a pre-polish grit and then the next stage is the polishing. Use plastic pellets too as they cushions the softer stones and helps polish them up in both stages. Don’t be tempted to skip the pre-polish stage as this gets rid of any minor scratches and really does a good job of pre- polishing. See instructions for using plastic pellets, I basically fill half the barrel with stones and make it up to three quarters with pellets, I then add enough water to just cover the stones, then add grit or polish powder. Basically, it’s your discretion, but just leave enough room in the barrel for the stones to ‘tumble’ i.e. to move around! The pellets can be used up to twelve times before you change them for a new batch. Don’t flush any pellets down the sink as they cause environmental damage.
4. DO NOT put the used gritty slurry water at any of the stages down your normal sink, it will set like concrete and you might end up having to have new waste pipes put in. Find somewhere in the garden you can tip it where it doesn’t matter but not next to your drains.
5. If you have rougher stones or want to wear down some stones more than the pre-polish stage, than use a coarser grit which will grind down more of the stone. Again trial and error is the only way to learn with this.
6. Reuse the pellets each time and save the ‘slurry’ that comes with it, you can use it next time (just add more grit or polish each time) Make sure you don’t mix the pellets for each stage – keep the pre-polish pellets separate from the final stage polishing pellets. Getting coarse grit in your beautiful final polishing stage can undo all the hard work already done.
7. Use separate barrels for each stage if you can afford it. I have three barrels. One for coarse grit (I rarely use) one for pre-polish and one for polishing. It just makes life easier than really having to wash and inspect each barrel if you only have one barrel for all stages. The plastic barrels are not too expensive – I got my spare plastic barrel for about £7. The rubber barrels are between £20 – £40 each.
8. Check the stones after 24 hours of continuous tumbling, after that every 12 hours, softer stone tumbles quicker so it doesn’t take very long to finish each stage. Sometimes the final polish can take a little longer and you want a good shine, so be patient and don’t worry if they take a little longer, an extra 12 hours can make all the difference between a fairly shiny stone and a perfectly shined stone.
9. Using soap powder and sugar. I haven’t tried it. I’ve only used proper grit and polishing powder. I’ve heard good and bad info about using them. Someone said the sugar can make it a bit of a sticky mess and it builds up a gas which you have to release every now and again or it blows the end cap off! That would be a mess which you don’t want over the tumbling motor and drive belt (if you have one) again trial and error is the way forward here.
10. Having trouble putting on the end caps? Run them under hot water or soak in hot water, this makes them more pliable to put on and they shrink as they get cooler making a good seal. You don’t want leaking barrels. Check your barrels for leaking about ten minutes after you start tumbling.
11. Rubber barrels versus plastic barrels. Rubber barrels are more expensive but are quieter and last much longer than the plastic ones. The plastic ones however are cheaper which might be a bonus when you’ve just paid out for a whole kit. The plastic ones I’m told last about a year but I think that depends on what stone you are tumbling. Coarse stone will be more rugged and do more damage than beach tumbled stone. I will let you know after a year!
12. Every now and then oil the bearings even if they are plastic but don’t get oil on the drive belt or it’ll slip and not run properly.
13. Looking after the environment. Make sure you don’t let any of the plastic pellets go down the drain or they can end up in the sea, some birds mistake then for fish eggs and this can kill their young, who starve from filling up their stomaches with plastic – heart rending stuff.
Dry Serpentine
Wet serpentine
See the difference between the two stones? Serpentine comes in many colours but you really can tell it’s serpentine by it’s smooth, silky, almost greasy feel – it’s very tactil especially once polished. Some serpentine is obviously green, brown or the one above which is a more subtle colour. Depends what you want.
If I think of any more tips I’ll add them but I hope this helps. I certainly needed some help when I first started especially as I bought my tumbler on eBay and it had no instructions.