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So you've fired your precious metal clay piece - what is this white stuff? It isn't a coating of anything that has to be removed, it isn't fire scale, or some sort of oxidation. It is actually the true silver you are seeing. What you need to do now is flatten and smooth it out to close the surface, and get the colour and silver shine we are used to seeing. This is called finishing or burnishing.
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BRUSHING - Depending on what finish you are after - matte or satin, mirror shine, antiqued - there are different tools to use. The first step is to use a stainless steel or brass scratch brush and a little soapy water. It seems like the stainless steel brush keeps pieces untarnished for slightly longer than the brass version. Just keep brushing and within a minute you'll see your piece just as you intended it to look. The brushing gives a soft satin look to the silver. You can either leave the silver like this, or continue with the options below.
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TUMBLING - Not shiny enough for you? The scratch brush has left minor scratches on the surface, so for more shine you'll have to keep polishing with something to remove these scratches. The easiest way, which requires the minimal elbow grease, is to use a tumbler with mixed shape steel shots, water and a burnishing fluid. Pop your piece (or pieces) in and tumble for anything between 30 minutes to 6 hours. Check your pieces every 30 minutes or so to see if you have reached the shine you are after. The tumbling will also harden your metal.
We supply a high quality, English-built tumbler with everything you need to get started. You'll find this on the shopping page. You can get it with a rubber or plastic barrel. The rubber barrel is slightly more expensive but quieter to run, and a lot easier to open and seal as it comes with a screw fitting. Easier than the plastic barrel if you have long nails!
With the tumbler you'll also get a manual with detailed instructions on how to polish your silver pieces. When I first started tumbling I realised it was almost impossible to find any detailed information about how to tumble jewellery, (how much water and shots to use for which barrel, which burnishing compund should be used, how many pieces can you put in?) so I designed this manual to make it easier for people.
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BURNISHING - Burnishing means to rub your piece with the side of a very smooth metal or stone burnisher (could also be the back of a spoon or similar smooth surface). This will also harden the piece. It really brings out the shine, and is one of my favourite steps in finishing.
Kepp your burnisher smooth - any scratches on the surface will create scratches on your piece. Sandpaper and polish your burnisher if it looks like it needs it.
Only burnish on surfaces which are smooth, with no scratches or marks. Burnishing won't remove scratches, it would only flatten them slightly, so file and sand the surface first if needed.
Of course you can get a burnisher from us, see the shopping page.
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HAND POLISH - If you don't have a tumbler - do it by hand. This gives you the real mirror shine. It takes time, but is quite relaxing. You'll need a set of fine grit polishing paper (From 600 to 1200 or 2000 grit) or sanding pads, and keep a small bowl of water next to you to keep the paper wet. You can also do it dry, but wet seems to give an even better finish.
- Start with the coarsest grit, probably something like a 600 grit, wet the paper or pad and rub the surface evenly in one direction (like left to right only). Keep the paper wet. When the surface is evenly polished with this paper, and you can't see any sharp scratches or marks, it is time for the next step.
- Fill the bowl with clean water and rinse the piece each time you change grit. Now wet the next paper or pad, say 800 or 1200, and start sanding. Sand across the direction you used for the previous grit (in this example, up and down only). The reason to do each paper in different directions is so you can see when you have removed all the marks of the previous grit. Rinse the paper and the piece itself regularly to keep them clean. Keep polishing until the marks from the previous grit has disappeared. Now move on to the final paper.
- (Change water, rinse piece, wet paper) With the 1200 or 2000 paper or pad, sand the piece in small circles. Keep sanding until the surface looks smoth.
- Rinse the piece well and dry it. To finish, put a small amount of silver polish on a polishing cloth and rub the piece. Rub, rub and rub. Finish with a clean, dry cloth and your piece should have a really professional mirror finish.
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ANTIQUING - You might want to add a patina to your piece. This is often used for enhancing details like engravings, textures or 3D modelled pieces. It also gives pieces a antique or worn look, by blackening or darkening all the little cracks and crevices. It really changes the way a piece of Art Clay jewellery looks, some designs looks better patinated.
The most effective oxidiser is Liver of Sulphur (LOS). This is applied after the brushing, on a clean piece. Mix a little bicarbonate of soda with warm water to a paste, and clean your piece with this before patinating.
The standard way of using LOS is to blacken your fine silver. Mix about a tablespoon of the Liver or Sulphur with a mug of hot water. Dip your piece in until it goes black, remove it and rinse under the tap with cool water. And then polish the highlights.
The LOS can also create a range a interesting colours; gold, red, green, purple and blue and grey. To achieve this there are a lot of different recepies, experimenting with adding ammonia and/or salt to the mixture. Also, use cooler water as this slows down the process and allows you to stop at the perfect stage. To stop the piece going darker, remove it and rinse with cold water. You can also brush the LOS mixture onto the piece, this allows you to be more selective with where the patina will go.
You'll find Liver of Sulphur on the shopping page. Keep your bottle out of sun and heat, and keep it closed - air and light will break down the mixture and make it less effective.
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