There are many techniques you can use to create a professional-looking piece. This article will review three of the most effective – executing repairs, sanding, and burnishing.
Sanding, polishing, and finishing are arguably some of the most essential aspects of the jewelry making process. When using metal clay, most of the finishing should be completed before it is fired while it is still dry. Work that is firm and dry is in the perfect condition to inspect it for scratches, blemishes, flawed connections, and other anomalies that you don’t want to see in the fired piece. Taking the time to examine your work before it is fired and carefully finishing it will make a significant impact on the overall success of the design.
Before you begin to sand, inspect all joints and connection points to ensure that they will be as durable as possible. Fill gaps, cracks, or air pockets, finesse seams, and strengthen thin areas.
Choosing the right material to make the repair will take experience and a good understanding of the various types of metal clay. The goal is to use a product with an appropriate amount of metal density for the specific task. A tiny pin-sized divot can be filled with a drop of thin paste or a dot of syringe clay. A gap in a pre-formed bail might require a ball of moistened lump clay.
All metal clay is primarily made of three things: powdered metal, binder, and water. That’s it.
Fill gaps with lump clay and a rubber ended tool
The more liquid the clay is, the more water content it has. If you fill a gap with thin paste, little metal will remain after the water has evaporated, and the repair will need to be repeated. Using a rubber-tipped tool to pack a small amount of moistened lump clay into a void will create a denser and more reliable repair.
On the other hand, using pressure to pack lump clay into an area of a delicate design may result in a break. In this case, multiple applications of moister syringe clay may be a better choice.
Syringe clay is also an excellent material to fill gaps that are difficult to access. Allowing the tip of a syringe to make contact with a gap will force the repair material deep into the space as the pressurized clay is extruded.
Repair a seam with syringe
Refine a seam with a rubber ended tool
A seam can be considered part of the design or it can be a distraction. To create a smooth transition between edges, use a tiny coil of lump clay or an extruded line of syringe to smooth the seam. Think of the strip of material that is used to bridge the joint between two different types of flooring and try to mimic that look.
Occasionally we’ll unintentionally make or sand a design too thin. The easiest way to strengthen it is to back the dry piece with a thin layer of lump clay.
Tip: If there are any air gaps between the layers, using high heat too soon may produce steam, which could cause the fresh clay to bubble
Sanding is a way to refine, alter, and pre-polish work before it is fired. Learning to perfect the edges of a dry piece is usually the first finishing technique students are exposed to, but edges shouldn’t be the only areas taken into consideration. Making sure all aspects of the work are examined before firing, including the back, edges, surface, and any added elements like bails or stone settings, is a necessary part of production. Even the inside of a hole or bail may need some attention.
Dry metal clay is much easier to modify, requires fewer tools, and is less time consuming than working with fired metal.
The assortment of tools and materials that can be used is virtually endless. The most common are:
Note: Hardware store sandpaper can be distinguished by color. Grey, wet/dry, papers are generally used for metal and metal clay, and brown paper is more suited for use with wood
Jeweler’s polishing papers
Sponge backed sanding pads and emery boards
Needle files
How a piece is held and whether it is placed on a flat surface or held suspended in the air will directly affect the outcome. As you sand, you are holding the work steady with one hand and using pressure with the tool you’ve chosen in the other hand. Finding the correct position and support is vital. Use too much pressure, and you’ll break the work.
Note: Any time water is added to previously dry metal clay, it is being rehydrated and will be more fragile and prone to breakage. If you use any kind of moisture as a sanding aid, dry the piece again before you continue
Refining an edge with a sanding pad
Coarse sandpaper is a standard go-to material when beginning the finishing process.
Keep the back clean, add a bail carefully and refine with a paintbrush
The back of a piece, such as a pendant, offers an excellent opportunity for more design details or texture. When it is blank instead, small flaws, divots, and scratches become unwanted focal points.
Even the tops of textured surfaces may benefit from a light sanding. There are sometimes flaws in the depressions of a texture sheet, a hair may have been pressed into the surface of the clay as it was rolled, or you may simply want to pre-polish the high points of a design. Most often, finishing paper is used for this task, but finer grades of sandpaper can also be effective.
Instead of sandpaper you can use a damp finger or sponge tool to soften edges or remove small amounts of dry clay.
It’s tempting to use saliva when finger sanding but is not a healthy habit to adopt and can be hazardous when working with base metals. Get in the habit of dipping a fingertip in a small container of water instead. Be sure to tap a wet finger on your hand or a towel to remove most of the water. Too much moisture can make a mess and makes it difficult to see the surface of the work through the water.
Tip: Invest in good quality paint brushes. Looking after your paint brushes will extend their life and benefit your work. Do not allow a large amount of paste or clay to fill bristles that are close to the ferrule of the brush, leaving clay to dry in a brush will cause the bristles to splay outwards. Placing a brush bristles down in a pot of water will bend the bristles and impair the brush’s effectiveness. Always clean, re-point and blot dry a brush before putting it away for the day
Use a damp brush in areas where your finger will not fit
Burnishing is a technique that is usually used for finishing fired metal clay. When rubbing the work with a hard tool, like a steel or agate burnishing tool, the metal crystals are being compacted and creating shine. Burnishing raw metal clay also polishes the metal content and smoothes the clay so much that flaws and scratches become more visible.
This technique takes some pressure and force and is usually used to smooth flat, un-textured areas in preparation for a mirror finish, but sometimes you might want to burnish the high areas of a textured design. It’s definitely a tricky technique and not a common practice but there may be times when it is called for.
This video shows the process of burnishing unfired silver clay using an agate burnisher.
