Firing Precious Metal Clay (PMC)

Firing is one of the most important aspects of working with Precious Metal Clay (PMC). As PMC is made up almost entirely of pure silver particles items can be polished even though they have not been fired. The only way you will find out is when the piece breaks whilst it is being worn. PMC will always look white once fired as this is its natural state. By polishing ie, smoothing the surface the PMC will gain its silver colour. The more you polish the brighter the silver will look.

 Once fired, PMC can be hallmarked as Fine Silver (.999) at any of the UK Assay Offices. You will find more information about this in the video clip ‘Hallmarking your PMC’.

To download and print our guide to firing PMC click here.

Torch Firing

Pieces the size and thickness of a 50 pence piece can be torch fired. Gently heat the piece, wait for the binder to burn off and the piece to glow a pale orange. Once the piece glows orange, continue for a minimum of two minutes and keep the whole piece heated evenly. If your piece starts to look silver on the surface you are in danger of melting your silver. Pull the torch up.

Once fired, quench in a cup of water to strengthen the metal. Please note applies to items that are made of PMC only. PMC items containing gemstones, glass or ceramics need to be left to cool.

 Kiln Firing

A kiln suitable for PMC needs to have a temperature control as the kiln needs to maintain the correct temperature for a minimum of 10 minutes.

The Evenheat Pro-Set Kiln is recommended for firing any type of PMC as well as ArtClay. This kiln can also be used for glass fusing, glass slumping and enamelling. You do not need to programme this kiln as the programmes are set in the factory.

Items that need to be fired in a kiln are items:

• larger or thicker than a 50 pence piece
• contain natural gemstones
• contain glass
• contain ceramics
• contain natural materials e.g. pods, leaves and paper
• 3D objects e.g. box shapes

Please note: The PMC Studio offers a kiln firing service please click here to find out more