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Barrelling Machine For Polishing Metal - Everything You Need To Know

"As the barrel rotates the shot inside it's acting like thousands of tiny hammers, planishing the surface of the metal and making it shine!"

On this page, we give in-depth information as well as our best tips and advice for working with the Barrelling Machine For Polishing Metal. We feature the most frequently asked question we are asked from customers when considering the barrelling machines as well as a few more we think are useful to know!

This machine is one of our most popular products, and is such a good investment! If there is anything you would like to know that has not been covered on this page, please feel free to get in touch. A PDF copy of the full instruction leaflet can be found for you to download at the bottom of the page.

The benefits of tumbling jewellery rather than polishing by hand

The main benefit of using a tumbler is the amount of time you will save compared to polishing by hand. You can make a batch of jewellery and tumble polish it all together, this not only saves you time but it frees you up to get on with the next task - which is particularly important if you are making your work to sell.

It is able to get into the nooks and crannies that polishing mops are not able to reach.

Do I need to buy anything else before I can use my tumbler? 

No, everything you need is in this kit! The electric motor base, 3lb plastic barrel, stainless steel shot and cleaning compound are all included so all you need to do is add water (and your jewellery of course).

How much does it cost to run?

It is very economical to run and will only cost about a penny to run it all day! If you consider that you’ll normally tumble many items at once this will reduce the cost to a fraction of a penny per piece. 

How To Use The Barrelling Machine For Tumbling Metal

The kit provided by Kernowcraft includes an electric motor base, one 3lb plastic vaned (paddled) barrel, 500g of mixed shape, rust-resistant stainless steel shot, 500g of barrelling compound (barrelbrite), easy to follow instructions and a 1 year motor guarantee.

Working with the barrelling machine is really nice and easy, just follow our simple steps...

Step 1

Open the lid of the barrel and pour in the stainless steel shot (shot is the name for the small stainless steel shapes which go into the tumbler and polish the metal. The shot you receive with the tumbler for metals is a stain-resistant magnetic stainless steel and consists of planetoids and balls.)

Step 2

Add in a level teaspoonful of the barrelling compound. Barrelbrite cleaning compound (also known as barrelling compound or gallay compound) is a special soap used to keep the shot and barrel clean. It also helps to lubricate tumbling - helping the polishing action, and minimise rust.

Step 3

Fill the barrel half full of cold water.

Step 4

Pop the lid back on, put the barrel on the rollers and start the tumbler!

As the barrel rotates the shot inside is acting like thousands of tiny hammers, planishing the surface of the metal and making it shine!

How long do I need to tumble items for?

It can vary, but to begin with try three hours and then check your work. If you think it needs longer, just pop it back in.

Will the barrelling machine remove scratches from my work?

The barrelling machine does not remove scratches - it only polishes! You need to remove any scratches prior to tumbling using files and wet and dry sanding paper.

Will tumbling my jewellery work harden it?

There are lots of conflicting opinions on this; however tumbling will only harden the outer layer of the metal. It would be more reliable to work harden your designs before tumbling, by either gently twisting or hammering (try the rawhide mallet as it won't mark your piece at all) your work.

Can I put small findings in the tumbler, i.e. headpins and can I tumble chains?

Headpins will survive tumbling unless they are tumbled with something else which they may get tangled in and bent as a result of this.

It’s worth considering this when loading up the tumbler. If you’re tumbling handmade findings like jump rings for example, the tumbler will remove small burrs.

*A handy tip for sorting your findings from the shot* - as our shot is magnetic it can be removed with a strong magnet!

You can tumble chains however you run the risk of them becoming very tangled (especially very fine chains).

Can I tumble metal items with gemstones set in them?

You should never tumble, for example, turquoise, amber, emeralds or pearls as this affects their finish and shine. With any other gemstones we really recommend you experiment first as we can’t guarantee they won’t get damaged during the tumbling process. Tumbling designs with set gemstones also runs the risk of getting water trapped underneath it.

Can I polish stones/sea glass in with the shot?

No, you’ll need to use grits and polish to tumble stones and not stainless steel shot - we have a separate machine and kit available for this - tumbling machine for polishing stones which you can view here.

Can I use the same barrel for steel shot (for metal) and grits (for tumble polishing stones)?

We highly recommend using separate barrels for shot and grits. If you are using the same barrel for both it is imperative that every single grain of grit is removed before using again for shot (this is virtually impossible). If one single piece of grit is left in the barrel it will scratch the work you’re trying to polish. It is really difficult to find one tiny bit of grit amongst the shot. It’s a risk best avoided!

What if I need a replacement part after I’ve had the barrelling machine for a long time?

The tumblers that we sell here at Kernowcraft come with a 1 year motor guarantee!

In the unlikely event of an accident or a fault with your barreling machine motor or if you need to replace any another part of your machine (at a cost) please contact us. We can put you on to the UK distributor who will be able to supply you with the new part and, if necessary, talk you through the replacement process on the phone.

Would this tumbler be suitable for heavy use (for example for classes)?

Absolutely yes – it’s designed to run and run so will be quite alright for heavy use.

I don’t have a workshop – can I use it in my house?

Absolutely – the tumbler is fitted with a UK plug and can be plugged into a regular mains socket.

This machine has a 1.6m cable, is CE marked and complies with EU safety standards. It has rubber feet to help stop it scratching your work surface and to stop it creeping across and falling off and as it’s a fairly compact size it can easily be stored in a cupboard when not in use.

How do I store the shot when I’m not using it?

Although the stainless-steel shot is 100% rust-resistant steel, you shouldn’t leave it lying around wet. It should either be left immersed in the tumbler mix of water and cleaner or rinsed and dried completely.

*A good tip for drying*- is to empty into a sieve, rinse thoroughly and dry in an old washing up bowl with a hairdryer!

How noisy is the tumbler?

Although the rubber barrels are much quieter than the plastic ones, they still emit a certain amount of noise.

If you are tumbling items for a long period of time you may wish to set your tumbler up in a utility room or similar to minimise noise levels.

Do I need any safety equipment and is it dangerous to use?

It is not necessary to have any safety equipment when using the barrelling machine for tumbling metal, however you must make sure any loose clothing, jewellery or hair is tied back out of the way so they don’t get caught around the roller.

As with all electrical equipment, don't get the motor part of your tumbler wet and don't touch it with wet hands. The motor is a low-speed, long-life design which won’t overheat if you leave it unattended but it is always best to unplug it when not in use or when it’s being serviced.

Can I put fired pieces of metal clay straight into the tumbler?

It is fine to put fired pieces of metal clay straight into the tumbler - just make sure they’re finished to a standard you’re happy with as the tumbler won’t remove any scratches or deep marks from filing etc.

Can I put hollow items in the tumbler or will they get damaged?

As long as they're not too delicate they should be ok - again we would really recommend doing a test before you put a finished hollow piece in the tumbler. You might also find that stray shot will find its way into the item if there is a hole in it, so bare this in mind also. It can be easily removed by rolling the piece or using a magnet to get the shot out of the hole.

Can I put items with a hole drilled in them in the tumbler?

Yes that’s fine – if you do find some shot managed to work its way into the hole then you can try shaking it, gently dropping it onto a magazine or similar soft but firm surface to dislodge it or using a magnet to get it out.

How do I open and close the barrel?

The end caps do not screw on but are a snug fit to avoid leakage, they can be eased on and off by simply soaking them in hot water.

How do I remove as much air as possible when attaching the lid?

Warm up the lid in hot water for 4-5 minutes and then place the lid on one edge fully and then gradually push the other edge over whilst pushing the center of the lid at the same time. Push the lid down as far as possible. Pushing the center of the lid where there's a slight ring embossed in the lid will help as it's flexible there and it will force out more air. Watch our video below for a demonstration.

How To Attach & Remove Barrel Lids For Barrelling/Tumbling Machines


If the barrel does not rotate

1. Dry rollers and barrel thoroughly.
2. lf the rollers appear glazed, rub lightly with sandpaper. 3. Ensure there is no oil on the rollers or barrel.
4. Check that the barrel is not under-loaded or overloaded.

If the belt slips

1. Remove the belt, wash and de-grease it, then dry it thoroughly and replace it.
2. Replace the belt if it looks worn. Do not attempt to tighten it as they are precisely tensioned before leaving the manufacturers.

Out of balance barrels

If the barrel is overloaded, or very large or irregular shaped items are being tumbled it is possible the heavy items will catch on the internal paddles when the barrel rotates. This can cause the load to be mostly on one side and can unbalance the barrel so it will not rotate properly. Either reduce the work load or if it is essential that the item is processed it may be worth trying a barrel without paddles (the proportion of shot may then need adjusting for optimum results).

Difficulty removing & putting on the lid of the barrel

The lids / end caps are a snug push-fit to ensure water doesn’t leak during the tumbling action. To remove the lid submerge the lid end in hot water for 4-5 minutes and it should come off easily. When replacing the lid, ensure there are no particles around the rim that could stop it sitting squarely and sealing properly and make sure you release any excess air by lifting the side as you slide them down. This is important as any air trapped can prevent a proper seal.

Black finish on metal items

If your jewellery has turned uniformly dark, it simply means that the dirt or deposits removed has overloaded the amount of burnishing soap compound you used and been uniformly redeposit onto your jewellery. Simply rinse out the black water, scrub and rinse the barrel, put in fresh water and more burnishing soap then tumble again. The darkening of metal pieces is almost always caused by not using the correct amount of burnishing soap for the number of pieces in the barrel and therefore affecting how much deposit the burnishing soap can hold in suspension. Dirty shot, base metal contaminants and even hard water, however, can all cause this too.

How to clean dirty shot

If the shot and shapes mix have taken on a dark appearance they can be cleaned by a simple method: Load the barrel in the normal way with shot/shapes, water and barrelling powder plus 3 or 4 small hard clean garden stones about 10 to 15mm in diameter (these stones must be hard and not prone to breaking up, round gravel stones are best). Run for 1 or 2 hours, wash out and the shot will now be clean, shiny and the normal metallic colour.

Michelle's Review

Watch Michelle from Buttercup Jewellery's thoughts on Kernowcraft's Barrelling Machine below!

"My Kernowcraft barrel polisher has been a game changer. If you need to save time I would thoroughly recommend getting one!"

Please note that we do not stock the ceramic pyramid chips featured, but do let us know if this is something you would be interested in seeing on our website.


If you have any questions, feel free to get in touch with our friendly team who will be more than happy to give you advice over email or on the phone.

You can learn more and find inspiration by visiting our Jewellery Making Tutorials, Jewellery Making Kits and YouTube Channel. Don't forget to follow us on social media and tag us in your designs on Instagram & Facebook, we would love to see!

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