Category Archives: Metal Working

All Rulers Are Not Created Equal

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Rulers? That doesn’t seem like a very important topic! Well, I have discovered in the last couple of years that all rulers are definitely not created equal. Now in my heart of hearts I knew that there were differences between rulers. Engineers and machinists use more expensive, and more accurate rulers. But one day, when I was in a hurry, I just grabbed a random plastic ruler to measure the link for a chain, and it came back to bite me later. Whether you are drawing out quilt blocks, measuring a pattern for embroidery, or checking the size of a link in a chain, you need accuracy, and consistency.

Most tape measures that we use for sewing are fairly consistent within the tape, but if you have doubts about yours, check it by doubling it back and seeing how well your measurements line up. As you can see in this picture, my tape measurements line up nicely. I always try to buy good tapes for sewing. I got in trouble once by switching between two tapes during a project, and winding up with almost a half inch difference. All of my current tape measures are made in Germany, and even though they are not the same brand, they are consistent. But I still stick with the same tape, just in case.

tape-check

My metal ruler agrees with my white engineers’ ruler, but my little yellow plastic ruler is off by slightly more than 1/16th of an inch over a distance of only four inches.

3-ruler-collage

I was trying to find the plastic ruler that got me in trouble, but I am sure that I threw it away. But I did find one of the kids’ old wooden rulers. This ruler brings up two very important issues. First, some rulers have extra space on the ends, to avoid the problem of wear and tear literally changing the length of the ruler. This is just something to be aware of. But this ruler has another problem. While the inch marks are nice and accurate, the number of divisions within the inch are wrong. Not just off a little, totally wrong. Yes, this is a test…

ruler-end

And just because the inches are good, doesn’t mean the centimeters are. I discovered that my lovely metal ruler, with the very reliable inches, has cut off the beginning of the centimeters, and is off by 1/2 mm. Now that may not be an issue for most people, but if I am cutting a piece of metal, or measuring a link, then my ruler needs to be precise. I simply slide in off the edge of the ruler and use the center to do my measuring.

Now you may ask, how did I get in trouble with an inaccurate ruler? As a production  jeweler, I keep notes about production details. The amount of metal needed for a project, or the size of the rings needed for a particular type of chain. Well, I had notes about a particular chain pattern. And they were wrong. Because the ruler was inaccurate. So, when I went to replicate the pattern. I cut the links the size that the notes said, and they didn’t work, because they are too small. So be aware, all rulers are not created equal.

 

Choosing Which Metal To Use – Part 4

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Last time we asked: What about silver plate, silver filled, vermeil, and gold filled metals and sources of metal?

I only use solid silver in my shop for cast pieces, plate and wire. The differences in cost between silver plate, silver filled, and solid sterling silver metal is, in my opinion, not sufficient to warrant using the less expensive metal. If I am using wire to make a knit chain necklace, the cost of the metal is important, but the majority of the cost is actually in the labor. Some of my less expensive bracelets and necklaces may have silver plated clasps.

Vermeil is sterling that is gold plated. This term is rarely used outside of the United States. I use vermeil, gold filled, and gold plated clasps for necklaces and bracelets. Vermeil is the same thing as silver gilt or gilt silver which was a very common period technique. Medieval people often could not afford solid gold items either. Gilt bronze was often used, especially for large items, like bowls and reliquaries.

English: Reliquary from Limoges, France, c. 12...

English: Reliquary from Limoges, France, c. 1280-1290, champlevé on gilded copper, Honolulu Academy of Arts (Photo credit: Wikipedia)

 

 

 

 

 

 

 

 

 

With the price of gold over a thousand dollars an ounce, solid gold is too expensive for your average customer. Gold Filled wire allows me to create affordable “gold” knit chain necklaces. Filled metal has a physically bonded layer of precious metal that is much thicker than plating.

English: Diagram of gold filled jewellery

English: Diagram of gold filled jewellery (Photo credit: Wikipedia)

 

 

 

 

 

 

 

 

 

 

 

 

And what about sources of metal? Any reputable metal distributor in the USA will be able to give you the actual metal content of an alloy. This is important for a number of reasons. The lead laws are one, but knowing the metal content of my supplies can be very important to my customers. Metal allergies are not that uncommon. By keeping an alloy list in my shop I can easily answer people’s questions about whether they can wear something or not. Most people will turn green from any copper alloy, I know that I certainly do, but some folks get serious contact dermatitis from nickel and other metals.

The vast majority (about 95%) of my metals come from a green US company that guarantees the metal content of their alloys. This is a serious benefit to me when I am developing new products. Each metal has very specific attributes. How much can it stretch or bend before it cracks? If I draw the wire down, will it become a lot harder and springier, or just a little.

I know people who enjoy making their own alloys, and the best of them have considerable knowledge in metallurgy. Knowing what is in the metals that you are alloying is critical. Using random bits of metal can create unanticipated issues, including lead content. I often wonder, when I see the prices of some of the items coming out of the former Soviet bloc countries, just what the metal content is. When a cast piece is selling for less than my cost to produce it, it makes me wonder. I think I will stay with guaranteed alloys from US companies!

Choosing Which Metal To Use: Part 3

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Last week we asked if there were any other issues with metal that we should consider. Well, two things come to mind immediately: metals other than bronze and lead, and knowing your metal source.

Metals were not carefully assayed in the past they way they can be today. The people who created the various pure metals and alloys were knowledgeable, and there is a considerable amount of pre-1600 written material about creating various alloys, but metal purity could not be tested with the same level of precision that we have modernly. Many alchemy texts have information on metallurgy.

When you are reading museum data base entries, the actual metal content of a piece is rarely listed. “Copper alloy” is often used to refer to any sort of bronze metal and the actually purity of precious metals is rarely noted. Until recently it has been much too expensive to test each piece to determine exactly the metal content. Larger organizations, like the British Museum, will sometimes reevaluate pieces as they clean them, and they sometimes test the metal content. Testing content has helped to reveal frauds, and modifications of artifacts, many of which were done in antiquity.

For anyone who has ever followed the types of silver that are available modernly, the two most common would be Sterling Silver (also designated as .925) and Fine Silver (.999).  Those numbers simply indicate the percentage of silver that is included in the alloy. There are other designations, including coin silver (which varies in silver content depending on the date of manufacture and the country), and Argentium Silver (which is a tarnish resistant form of Sterling Silver with special properties). The terms Bali Silver, Thai Silver, and Mexican Silver may be used in a retail setting, but have no legal meanings. Nickel Silver, or German Silver is silver colored, and does not actually contain any silver at all. It is a copper alloy.

There were an assortment of silver alloys that were used in period that are not usually used modernly. Billon has been used since at least ancient Greece. It is a silver colored alloy which usually contains silver and other metals (usually copper), and may sometimes contain mercury. It was commonly used for making coins and medals. Electrum is a naturally occurring alloy of silver and gold, which has been used since at least 3,000BC by the ancient Egyptians. It was used widely in coinage and jewelry manufacture by cultures as varied as the Egyptians and the Vikings. There are major deposits of natural electrum in Anatolia (Turkey).

All of the silver pieces that I currently make for sale in my shop is classified as Sterling Silver. My cast pieces are solid sterling, and the wire and plate that I use in my toiletry sets, needles cases and chains (both knit and link) are all solid Sterling Silver.  I do not currently work with Argentium silver. Sterling Silver alloy was used during Medieval times.

Next time: What about silver plate, silver filled, vermeil, and gold filled metals, and sources of metal?