Gold Filled Wire- What is it ?
You've heard the old phrase “All that glitters isn't gold”. This is true when it comes to the jewelry world. With the cost of high karat gold becoming more and more expensive, jewelry manufacturers and crafters are now using alternatives to create items that have the look and feel of real gold but without excessive cost.
Increasing in popularity is gold filled wire, but many people are confused as to exactly what it is and how they can use it. So let us explain…
The term ‘gold filled’ is a little bit misleading. You might think that it's some kind of wire which is filled with gold. It's this terminology which confuses. In reality, it is gold wire - which is filled, (equally confusing). Put simply you've got an outer layer of real gold but an inside core of non-precious material, usually brass. The outside of the wire is gold, your jewelry will be gold colored, look like gold and feel like gold, because on the surface – it is.
You can see in the illustration above that the gold filled wire contains a brass core. It's important to realize that the outer layer is real gold. Likewise, you can purchase gold filled sheet. Referred to as a double clad, which is a sandwich of a brass sheet between top and bottom layers of real gold. There is also a growing range of gold filled findings available, which are ideal to use in conjunction with gold filled wire and sheet to complete your pieces.
Pepetools.com offer an increasing range of gold filled findings, finished chains and accessories for your own projects.
Gold Filled vs Plated?
Gold filled is far superior to gold plated, which is only a microscopic thin layer. With gold filled the gold is mechanically bonded to the brass core, so it won't slip, move, or peel off. You may also see it referred to as rolled gold or gold bonded or simply as GF. To be described as ‘Gold filled’ the outer gold layer must equate to at least 1/20 of the overall weight. Another way to look at it is that 5% of the overall weight, is pure gold.
Note on gold.
The outer gold surface is described by Karat (or Carat in the UK) just as solid gold wire is. Karat refers to parts per 24 (24/24 parts = 24K). Pure gold would be 24 karats, written as 24k or 24Ct (UK). Other karat numbers are fractions of this accordingly, for example, 12k is 12 parts per 24 making it 50% gold. Proportionally 18k contains twice as much pure gold as 9k. You may also see gold and other precious metals described by a three digit number. This is the proportion of pure gold per thousand. Rather like saying a percentage but without the decimal point. So as above 12k gold is 24/12 or 50% and is written as 500. Likewise, sterling silver is often seen as 925, meaning 92.5% pure silver. But Karat is only used to refer to gold.
Table showing the gold ratio for 'every' Karat.
Note pure gold is usually written as 999, as it cannot be guaranteed absolutely 100%. Different countries have varying minimum standards on what can be called gold, but you seldom see gold below 9ct (Minimum legal is 8K in Germany).
With 9, 14, 18, 22 being popular in jewelry.
When referring to gold filled wire as being 14k, this is only describing the gold outer layer, not the brass core, or the wire as a whole. Regardless of the karat, the core will remain brass, and the outer layer must be a minimum 1/20 of the total weight (not thickness). The amount of pure gold in the outer layer will vary depending on the Karat as above.
The main advantage of using gold filled wire in place of solid gold wire is a huge cost saving. Especially when using heavier gauge wire or longer lengths, the cost of buying solid gold wire can quickly mount up. Whereas making the same project with gold filled wire can be much cheaper in comparison.
As an example we can compare 12 feet of wire.. (prices correct at the time of writing)
12 feet of 1 mm 14k gold wire costs £1,338 (approx. 1 Oz)
12 feet of 1 mm 14k gold filled cost £117 pounds.
12 feet of 19 ga 14k gold wire costs $1,427 (approx. 1 Oz)
12 feet of 19 ga 14k gold filled costs $57 ($83.53 per Oz)
It is clear to see that huge savings can be made in material costs, by utilizing gold filled wire in place of solid gold. Remember that the outer layer is still the same 14k gold, so the appearance of the piece will be the same.
Note also that the USA uses AWG American Wire Gauge, whereas the UK uses metric mm. Therefore 19ga is a fraction smaller than the UK 1mm. Hence the slightly cheaper USA price.
The 12 feet of solid gold 1mm wire above will weigh approximately 1 ounce (32g), the same 1mm gold filled wire weighs 25.5 g. Gold is a very heavy material and the higher the karat the heavier it will be. Hence why gold filled wire is much lighter. Although solid, the central core of brass isn't as heavy as gold. This could be a useful factor in larger pieces, as the same size item in gold filled will be slightly lighter. Conversely, if you were setting out to make a 1 ounce bracelet, a gold filled item could be slightly larger compared to solid gold of the same weight.
Although the price saving is attractive, many people are still intimidated by it and are unsure how to work with it. So here are a few important considerations.
First, let's talk about the wire. The gold layer surrounds the wire 360 degrees seamlessly. However, if you cut the wire then the very end will reveal the brass core. If you plan to solder the ends together such as making soldered jump rings, then once soldered the only thing you will see in the final jump ring is real gold. But if your design means that you will have exposed ends of the wire then you need to consider how you can finish these or solder them. Consider for example making claws to hold a cut stone. Cutting grooves into the sides of the wire would reveal the brass core, and trimming the tips would also reveal the brass core. So perhaps not best in this situation. Ideally, you want the gold cladding to be kept in one piece along the length of the wire. And the cut ends to be hidden, covered, or soldered. (also see notes below about gold plating options)
The gold filled sheet also requires the same consideration. Whichever way you cut it; the edges will always reveal the brass core. Only the top and bottom surfaces will have the gold cladding. So again, you may need to consider how you are going to cover those exposed edges. (If you want to).
As the outer surface is gold then when it comes to soldering you should simply treat it as gold. Using traditional gold solders and matching the Karat and color of your wire.
It is strongly recommended that you stick to lower temperature solders such as extra easy, and easy. Solder gently with a small soft flame, only heating the area to be soldered. Even if you are using syringe solder paste, it is still advisable to protect the rest of the piece with flux to prevent oxidization. Avoid excessive overheating, as this can cause copper to seep through the gold layer. This is rather like fire scale which occurs on silver and can be tricky to remove. The thin gold layer will conduct heat quickly and excessive heat in one small area could lead to melting of the surface gold, which will be irreparable. flux the whole piece, use low temperature solder, and heat gently. pickle as normal.
See Pepetools.com for all your soldering supplies
including solder, Pickle and flux.
A very important consideration with gold filled is not to over polish it. The gold can usually stand a little gentle buffing. But keep it to an absolute minimum, especially if using abrasives such as emery paper, or harsh cutting compounds such as Tripoli. It is very easy to wear away the gold layer revealing the brass core. Light tumbling in a barrelling machine or magnetic polisher at low speed will be more than sufficient. Alternatively, gentle cleaning with a soft brass brush and soapy water will help to burnish the surface without removing any material. A special gold polishing cloth will be safer than using a buffing wheel.
Using a gold polishing cloth to gently buff the piece.
Click to see Pepetools specially selected polishing cloths.
Pepetools Digital Pen plater.
The Pepetools Digital Pen Plater.
Ideal for simple, quick gold plating.
click for more info.
Another useful tool when working with gold filled, is the Pepetools pen plater. This easy to use desktop tool allows you to gold plate small specific areas with accuracy and precision, using a special 'pen'. This gives you the opportunity to very quickly touch up any exposed edges by simply running the pen over them and plating them with a thin layer of gold. As always, it is important to match the Karat and color of the gold you are using.
Above, using the Pepetools Digital Pen plater,
to color match a soldered jump ring to a Gold Filled Bracelet.
Click above to watch the video.
See the full Blog here abut gold plating.
Top tips: -
What this means is that gold filled material is less forgiving, as it's not easy to polish out tool marks afterward. If working with wire you may find nylon jaw tools a big help to avoid creating tool marks in the wire. When working with sheet, if it comes from the manufacturer with a plastic covering then keep it in place as long as possible. Alternatively, cover the surface with paper masking tape to protect it while you work on the rest of the piece. Work cleanly and be mindful of filings or debris on your bench peg that may scratch the gold surface. Just good practice anyway.
The gold filled wire is increasingly popular with chain mail designs. With the outer surface being gold, it won't tarnish the same as say brass wire would. The thick outer layer will last much longer than gold plated, or anodized wire. With chain male designs and jump rings, there is often no need to solder, hence avoiding the above considerations. So, a combination of gold filled rings with sterling silver rings can create a very luxurious item with no extra effort at a fraction of the cost of real gold.
Persian Bracelet made with sterling silver and Gold Filled wire.
by Dave Wilson