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American Copper Cookware History {Part 2}

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When smiths (of both tin and copper) had new machinery available to them, the production of all tin and copper sheet products went up, unsurprisingly. By the 1850’s, the machines were being made in multiple quantities and without too much variance in price from the decade prior, so if you spent your life savings on one, you were likely going to have a piece of machinery that only went up in value as time marched along. Plus, you were able to make things a bit faster, make more of them, and sell more of them, so you were making more money anyway. Investment, much?

Still, the machines were dear – most of them costing a full month’s wages. If they broke, they’d need to be repaired by a blacksmith, as they were all made of iron. And they were heavy, thus tying a smith down more and more to one location, creating a pivotal change in the wandering days of most tin tinkers.

While the western regions of America still were pulling and changing and growing – and both stationary and wandering tin and copper smiths could be found, the east coast saw a deeper settling down in the trade, where larger shops were found in big communities, and goods were churned out at a rate that had never before been topped.

The machinery used for the creation of the cookware was (and still is!) as specific to one job as the stakes that came before them. As I mentioned in my previous post, stakes in a stake plate were used to create seams, edges, burrs and shapes in the sheet metal. There are a myriad of stake types – each for a very specific purpose – and the new machines were not much different in terms of specificity.

A burring machine created a burr. A setting down machine set down seams. A grooving machine put the grooves into the seams. A wiring machine…well, you get the picture.

Another change was that after the American Revolutionary War, larger pieces of copper sheet could be formed here in the USA, allowing for larger, more robust copper items. Machines accommodated this. Large and small burring machines became available. Particular tools were built to help make a fast double seam that didn’t damage the softer metal. Soon a smith workshop could be as “automated” as the Industrial Revolution could make it.

But the Revolution also brought about new tools that eventually completely automated cookware manufacturing with different metals as the base used for forming, rendering tin and copper cookware obsolete. The renovations of the blast furnace and the inexpensive cast iron, enamelware, and in the early 1900’s, the advent of cheap aluminum cookware forced tin and copper fall to the wayside as kitchen staples, not to mention the invention of stamping sheet metal, which made a tinsmith’s job easier (the tricky work was done and you could just assemble) but also eventually took over the job itself.

Still, the need for tin and coppersmiths never completely disappeared. Tinsmiths are still employed by larger manufacturing companies to handle anything from ductwork to forming the tin pieces of products en masse. Finding someone who can re-tin a copper pot is next to impossible, but there are several in America with the know-how and the generosity of spirit to train people to pass along the trade (I’m one of them). Coppersmiths are few and far between as well, but their work is valued as artisanal and/or useful.

American copper cookware is also slowly finding a renaissance now, here at House Copper, with a mix of modern and vintage crafts to create the pieces, which is, in my opinion, a great marrying of old and new traditions that are the bedrock of our American manufacturing history – from hand-made copper to machine-spun.

It’s beyond cool, you know?

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Copper Cookware Made from Scratch

As an apprentice tin and copper smith, I get to play with sheets of tin and copper all the time. Of course, tin is much easier to create kitchenware with, but in this post I’m going to wax a bit poetic about copper and discuss the bare basics of what coppersmiths were up against prior to the Industrial Revolution.

If it weren’t for the earlier examples of copper cookware in America, we wouldn’t have the copper heirlooms from the 1800’s that are still prized today in kitchens around the country (and around the world). I believe there is tremendous value in understanding the art and technique behind our modern kitchenware (one can only know much of something if one is aware of what came before). The ancestry of our current copper cookware owes much of its design, and certainly its continued use, to these older, handmade versions of itself.

Before we had delicious looking copper cookware from across the world, we had original, handmade American copper cookware. Raised, braised, crimped and cramped, the copper sheet that was used for making vintage copper bowls, kettles, and pots was, prior to the Industrial Revolution machinery, thinner than it is today. It was also, because of that, more malleable for the simpler tools available to the time period.

In the 1700’s, in America, coppersmiths were few and far between. This was due to a number of factors. The first is that there was not much copper sheet with which to make objects. It was sometimes mined in the colonies, but it was sent back to England to be processed (smelted and rolled) before being re-shipped over. It was also only sent over in very small pieces instead of long rolls, so coppersmiths were obliged to braise or rivet together several sheets of copper to make larger kitchenware. Also, the King preferred us to just buy ready-made copper pieces from England.

There was also very little need for a full-fledged smith at the time – only large cities and ports could support a full time artisan. Many smiths had to try their hand with several kinds of metals. Say you might be well-versed in copper, but you’d also be required to repair tinware, work with silver and pewter, and likely have a touch of understanding with the blacksmith trade.

If you were not an established smith in a large town or city in America, you likely were a tinker. Spending your winters forming items out of copper (or tin), you’d then wander around the area in better weathered months selling the wares you’d made throughout the cold season as well as taking odd jobs repairing the tin and copper pieces of your clients.

This means that most smiths were quite good at doing most copper work with hand tools. Eventually, a smith may have found a place or the funds to set up shop, though, and the 1700’s smiths had the use of many types of stakes made by the local blacksmith at his wrought iron forge, as well as large and small snips (scissors). You’d make coppers (these were soldering tools made of copper) or braise together a cramp seam of a copper vessel. By hammering and “raising” the copper sheet, you could make small bowls and kitchen tools. Using copper wire, you could make rivets and piece together even a basic coffee pot with the limited sheet sizes you’d have from the Crown.

Thanks to the machines made in the mid 1800’s, working with sheet metal became far easier and efficient. The same tools that tinsmiths used once they became more stationary were also available to coppersmiths.

This meant that the coppersmith no longer slaved with snips, stakes and small hand tools only – though tinkers still would utilize the more mobile hand tools for many more decades – but also could start to rely on faster, more efficient tools crafted for “industrializing” the trade. Copperware was still measured and made by hand, but suddenly larger metal mechanical tools were available to raise a burr, groove, roll, cut and wire metal pieces into shape. While smiths could still do everything completely by hand for old time sake, it was possible to make more items with the same amount of help in the shop. The increased productivity and efficiency meant that copperware could become more affordable to the public.

So if you’re well-off and have a lot of copper, or have a single, treasured piece, just sit back and stare at your cookware and think about it’s predecessors: how it was all made, by hand, piece by piece. Pretty amazing, isn’t it?

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A Modern Apprentice Learning a Vintage Trade

I am beyond lucky, fortunate, and blessed to have the opportunity to be an apprentice metalsmith. It’s also sincerely amazing that this happened by complete serendipity.

Starting HCC required taking on multiple crash courses of research projects, developing metal cookware, and networking among myriad places to build the network of artisans. I not only was learning by fire, but also was crazy lucky to meet these great guys around the country willing to share their knowledge and mentor me. It’s this big awesome culture of creating, giving, and support that was completely foreign to me, and it kept getting more fantastic the further down the rabbit hole I went. Not only does it lend me  authenticity as an American cookware designer, but there is some earthy genuine delight from touching the metal myself. To do this right, though, to really be “authentic,” I needed to get my hands dirty.

Finding Bob, the master tinsmith, who happened to live up the road from my house was cooler than cool. After popping up to see him in action, he invited me to come and see him do more projects and try my hand at them. From there, it progressed quickly and naturally to being his apprentice. Now I get to go up and learn and watch and bang on metal twice a week, which is of course not nearly the same as full immersion as the apprentices of old, but it is just right for me, mom of 3 little children and a business owner. Together, we’ve taken on huge orders, custom work, and learned new parts of the trade. And every single day, I’m challenged, I learn, and I get to really touch what I sell.

So…metal apprenticeships are:

A lot of watching

A lot of asking questions

Lots of information being told verbally, and I’m not very good at remembering unless I write it down. So it’s a new way to learn!

Some burns

Getting hands on very vintage American copper cookware

Trying to help, but mainly creating more work

Oodles of mistakes

Cut fingers from sharp metal

Using a lot of tools and drills

 

A few banged up thumbs

Seriously killer awesome experiences making metalcrafts from scratch

Gaining old knowledge from masters who are ridiculously smart

 

 

Being an apprentice starts out by watching the master make a few projects. For me, that meant watching the master make tinware and then copper cookware the old, vintage way. There’s the way to make things using tools from the 1700’s and then there’s the way to do so with the tools from the 1800’s. The 1700’s copper and tinsmiths used a lot of snips of various sizes, pliers, stakes, anvils, and hammers, for instance. Smiths who adhere to those methods strictly are considered to be more “purists” than the smiths who bring in the “modern” tools, which were made in the 1800’s and essentially revolutionized the metal trade. The tools are still completely managed by hand, but they sped up the process of making the cookware. What usually took a lot of time to painstakingly cut out a circle of metal with tin snips could now be accomplished in a matter of seconds with the circle cutter tool. For example, burring, which normally took lots of time over a curved stake and some hammering, now could be done around a machine (though the machine has its own idiosyncrasies…any smith who has ever used a burring machine knows how finicky it can be!) quickly and evenly.

As an apprentice, I get to learn both of these methods, though I admit some fondness for the tools and machines from the 1800’s if only because I’m not very good at using snips to cut circles. It’s also because it’s faster and with little children underfoot, right now I’m all into a bit of speed or it will take a month to make a mug.

Regardless, I love that I get to learn an old art form, that the items we make are useful, and that with the knowledge getting passed along, another generation can carry the torch and keep the trade alive. That is hugely important to me, and those who do this feel the same. Keeping a trade a live, in snippets of oral history and hands-on learning at a time, is worth every minute.

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Copper the Element

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I must have known copper was something amazing when I used it as one of the colors to my wedding décor back in 2006. That was before using metallic at weddings was considered fashionable, so I felt far ahead of the trend, using copper, as it were.

But what makes copper so fantastic on a pure, elemental level? What makes it such a perfect conductor of heat, or metal that bonds beautifully?

First, let’s start with the copper on the periodic table and it’s material science.

Copper’s atomic number on the table is 29, and it’s symbol is Cu (which I never understand, as there’s no “u” in the word copper…it’s like having a US state abbreviation that doesn’t completely match). The atomic mass of copper is 63.546 u + 0.003 u. The melting point of copper is 1,984 F (or 1,085 C), and the thermal conductivity rate is 386 W/m K. Copper’s coefficient of thermal expansion is 17 per degree C x10^-6. Pure copper rates dead soft on the Rockwell C hardness scale, and is under the “non-ferrous” metal heading, meaning it does not contain any molecules of iron.

Whew. So, if that information helped you out, you’re welcome. I feel smarter just writing it all out in one place!

Copper, compared to other metals, is not highly reactive. That means it doesn’t react to other natural elements the same way iron does, for example. Attacks of oxygen and hydrogen (or water, for that matter) are usually futile – copper needs to be heated to at least 300 C to change it’s molecular make-up and become copper oxide. Iron, on the other hand, just needs to be exposed to air to make iron oxide (aka rust).

Copper can change/bond to other metals with the exchange of electrons. Elements are constantly forming covalent bonds between other elemental atoms (when an element may share electrons with other atom) or losing electrons to become positively charged. When that happens, the lost electrons move to another element, which is then negatively charged (that middle school science class coming back to you yet?), creating an electric (like a magnet) attraction between the two atoms, which is called an ionic bond.

Most metal elements/atoms lose electrons when they form the ionic bonds with other elements. However, copper is unique as it can form two ionic bonds. That is to say, once electrons are exchanged and the atom becomes less stable, it can combine with other elements (such as oxygen, for example) in two ways instead of one. This means deep molecular change can occur at a faster and higher rate when copper comes into contact with other elements. Take, for example, an item sitting outside in the rain. It’s a brass item (containing copper) and as it rains, the oxygen and carbon dioxide create a copper carbonate as the copper reacts with the rain in multiple ways. The brass item is covered with the greenish copper carbonate, thereby protecting the brass item from further corrosion.

For all the numbers above, copper certainly doesn’t come out of Mother Earth so pure and beautiful. We have to mine it out, and it comes out as copper ore, which usually contains only 1% of metal, so the ore needs to be floated. The refineries will pulverize the ore, mix it with water, and then pass it through water-filled tanks.The chemicals used in the water produces foam, which traps the copper minerals on the surface so they can be skimmed off, leaving the remaining ore. This is the part where the type of chemicals (or lack thereof) can determine how a copper is deoxidized, or whether it might turn into an alloy of copper instead of remaining pure. The finished “product” of this process is now about 25 – 35% copper, which is sent to be smelted.

Smelting uses high temperatures to finish purifying the copper. The first stage removes more copper from the ore by heating it with oxygen gas. From there, the “blister” copper goes through a fire refining and electrorefining stage, which results in a 99.99% pure copper.

When you have pure copper, the bonding abilities of those electrons are at a very high peak. Copper is conducting heat at nearly the perfect level of 386, and it is able to bond with silver or tin easily (depending on the chemicals/elements used to extract the copper from the ore – certain ones actually hinder the copper’s bonding ability), creating a molecular bond that lasts, at least in cookware, for a good chunk of time.

And that, all that science put into one place, is probably (now that I know way more about copper than I did at my wedding) what makes copper cookware, to me, so incredibly cool (and, of course, beautiful).

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Copper Cookware Rivets

Copper pots and bowls all have handles. They are usually either of brass, iron or steel and occasionally copper. But have you ever looked at how those handles are attached?

If you go into the kitchen now and look at those handles, you’ll also see rivets, at least where cookware is concerned (or, if you’re like me before I became educated in kitchen tools, I called them ‘nails’ or ‘screws’).

The interior of that pot or bowl plus the type of handle material will determine the type of rivet used. Rivets, as small as they are, are a necessary, integral part of creating long-lasting cookware. Choose the wrong rivet, and your pot will either come apart, handles will wiggle free, copper will disfigure, or the interior coating won’t stick. There’s a good amount of physics and science behind rivet choice, much of it having to do with thermal coefficients, molecular bonds, and even rivet length. Because it’s such an overlooked, but significant piece of the cookware puzzle, I thought I’d break it down, so that you too can understand exactly what you’re looking for when deciding if a piece of cookware is put together well.

Thanks to some generous mentorship and a healthy drop of research (even going back to grade and high school general chemical element textbooks), rivets have become both easier to understand, and, at the same time, complex little organisms in their own right.

 

Today, rivets start out as huge coils of metal – stainless, brass, aluminum, copper, or other types of steel, all with varying types of alloys – in various thickness or diameter. American rivet makers have electronic equipment now – rows of automated machinery made anywhere from early 20th century America to overseas in the East or Italy and beyond. Our rivet maker loves the one made in Vermont in 1917, swearing that it’s held up far better than other imports.

Rivets also have their own idiosyncrasies that require specific tools to be made and fit to the machine that is pulling the wire, to create whatever head (round, truss, flat, etc) is required, as well as the length of the rivet, and the finishing of the end (straight vs chamfered). Some rivets are tubular, or semi-tubular to a certain depth within the rivet instead of a solid shank, shouldered (a smaller diameter on the end of the shank), self-piercing, countersunk, collar, or brake. Again, our rivet maker does a lot of the tool making himself – essentially making a mold or jig that allows a machine to pump out thousands and millions of rivets. (This is one of those lost arts!)

The wire is then fed into the machine, where the head is formed, and any finishing to the bottom of the rivet happens right before the rivet is released into a bin. Many rivets are tubular or semi-tubular, unlike the ones used in kitchenware, which we spec as solid shank to manage the pressure of the rivet gun through the multiple layers of metal. Solid rivets are by far the strongest type made, and annealing can be done to make a rivet more durable or ductile depending on the needs of its final applications and use.

 

In kitchenware, the final application of the rivet is taken into account also with understanding the type of metal that the rivet will be joining. Certain types of metal do not bond, or have enough thermal expansion (heat elasticity) to be the right material used to be the connector of two joints. That’s where metallurgy and chemistry come into rivet decisions – a choice that should be made based on the longevity of the materials working together vs the least expensive manufacturing option, though obviously economics come into play, too!

Kitchenware rivets are usually holding together two dissimilar metals – either in molecular make-up or in terms of shape. Even a stainless steel pot, with stainless steel handles, will not be created as one entire piece. The body component will be spun on a CNC from sheet metal alone, and the handles created elsewhere. There is also a likelihood that the handles are made of a slightly different alloy of steel than the body. A manufacturer will want a cookware body to be higher in thermal conductivity than the handles so that the cooking surface heats as evenly and quickly as possible but the handles don’t necessarily heat as quickly. Therefore, even though you have a full steel pot, you have two disparate types of steel you’re going to connect together. You wouldn’t use a pure copper rivet at this juncture – the copper would heat and cool so quickly that the rivets themselves would not be able to stand up to the slower heating that surrounds it in the form of the steel, likely either cracking or failing completely. Even though you may have two types of steel alloys, one would use a similar metal with a similar expansion rate, in this case, a steel rivet.

In terms of copper cookware, which we make here at House Copper, we need to take the tin lining into account, just as, say, Mauviel does with their stainless steel lined copper cookware. For instance, a copper pot that has a steel interior is, first, not 100% pure copper because it needs to have a lower coefficient of thermal expansion to match the slower expansion rate of the stainless interior, so they add a few alloys in small percentages to the copper make-up, like Falk did, creating a copper alloy usually molecularly made of 99.58% copper, .40% aluminum, .02% boron. Sometimes they will replace the aluminum with zirconium or titanium. Still, the small additions of the other types of metals is all that is needed to slow the coefficient of thermal expansion so that the copper can (semi-mechanically) bond better with the stainless chromium/nickel steel as the zirconium, in particular, acts as an inhibitor – meaning the copper crystals, even with re-heating and cooling to form a pot, do not change as dramatically, creating a far more lasting bond than other types of stainless steel lined copper pots.

Our pots are lined with tin. The tin interior exchanges electrons with copper when the two are heated, creating a solid molecular bond instead of a mechanical one as discussed above. But we do like to add handles to our copper cookware, of course, and those we don’t want to make out of copper. It would heat too quickly and be too weak to hold up to the weight of a full pot, let alone be too malleable. We use pure iron handles, but they’re poured with a ductile grade treated with heat for extra machinability and elasticity (meaning the iron nodules can elongate with heating instead of cracking). This means a rivet needs to work with both the iron (which heats slow), the copper (which heats fast) and the tin (which also heats fast). The rivet must therefore absorb a lot of heat and move quickly to compensate for the slower moving heat of the handles. Both aluminum and copper rivets have this capability. However, tin does not react/bond to aluminum well, leaving our only option to be a strong, solid shank copper rivet.

Without the right rivet…your pot will fail in multiple places both in performance and during manufacturing, or at the very least, deform with use. A good manufacturer will want to know the provenance of the rivet to make sure it is made of the proper alloy/molecular make-up required for performance as well as overall quality control. Use a bad rivet, and the entire piece of cookware can quickly become junk.

Hence, a rivet really holds it all together!

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Tinning Copper Over Fire

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There’s something a bit exhilarating about huddling over a hot fire with some metal in your hands and making it melt.

Our House Copper copper pots are hand tinned here at HC, and while I (Sara) do it now, I couldn’t have learned at all without the beautiful work and constant mentorship of Dan, our original tinner. He was awesome enough to lime up a few of the HC lids at the 2016 tinsmith convergence, show how it is done, and hand over the whole kit for me to try.

First of all, disclaimer! I personally believe it’s the best (affordable) way to line cookware (especially great copper cookware that is spun in .060 – .090 (that’s 1.5mm – 3mm)) because of the molecular bonding occurring between tin and copper with heat, creating a single molecule thick of bronze. Now you can continue, knowing I’m biased, but backed by some science, too!

My first foray into tinning was a thin little number called Galvanizing and Tinning: A Practical Treatise on Coating by W. T. Flanders, published in 1900. While many parts of tinning has remained the same, we’ve obviously modernized in the past 118 years, and learned even more about the science of cookware.

 

How a traditional tinner’s workshop would have been laid out

(image from a book which allows reproductions of the material)

 

 

 

Our copper cookware is formed from pure copper sheets, which need to be deoxidized during the smelting process. This is done using phosphorous. I like this particularly because phosphorous is an element on the pure periodic table, which means we aren’t dousing the cookware in a ton of chemicals even in its infancy. Plus, the phosphorous allows for a better tinning finish.

Back in the 1700 and 1800’s, tinning (and soldering) used to be done using small metal tools, aptly named “coppers” for small pieces. Big pots and kettles were done in a tin shop. Most work in the molten tin was for covering cast iron pieces to prevent rust.

 

Traditional tinsmith coppers, used for soldering tin seams on cookware, etc.

 

 

 

But hot forge tinning was done (and is still done) with either one kettle of tin or more. The tin is maintained at a temperature of about 500F, and the work is cooled off in hot water ideally, and dried in sawdust. This is how it was done for hundreds of years, and how it’s still done today!

A few things happen when dealing with tinning copper, especially copper cookware that has iron handles. The handles themselves are attached with copper rivets, which helps adjust for the different coefficients of thermal expansion between the copper and the iron, but the iron will still pull off the heat from the copper body when heating up the material for tinning.

This means that when you’re starting to tin over fire, beyond what it takes to heat up the limed up copper (cover the cookware with lime ahead of time to help protect it from direct flame), the place where the rivets are mushroomed is actually the coolest part of the piece. That’s what needs a lot of initial heat to compensate for the “cooler” metal attached at that point pulling off the rising temperature.

You’ll apply flux after you’ve heated the copper cookware for a bit. There is ongoing debate in tinsmith circles about the best flux to use, and everyone has particular choices based on the application of the tin. (I’ve been dealing with both Acro Flux and Harris Stay-Clean, for those of you who care!) Once the flux reaches just the right temperature (usually it starts to almost ‘brown’), you start running your bar of tin, spreading, then wiping, and then dousing in water before cooling it in a big box of sawdust.

Once it cools completely it can be cleaned and polished and the handles are treated. Some people prefer butcher’s wax, but we’ve experimented with using organic flaxseed oil, sometimes mixed with traditional, old fashioned stove blacking (the kind used on pioneer potbelly stoves), which is basically powdered charcoal.

And you’ve got a tin-lined copper pot. Easy as that!

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How to Make a Copper Bowl

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copper bowl, copper cookware, pure copper, pure copper bowl, thick copper bowl, original copper bowl, american copper bowlIt’s been a bit of a journey to get these copper bowls into existence.

First, there was the process of the design. My dear friend and colleague Julia is an amazing product designer, and we came up with the volume and tweaked the bead (the curved edge on the top) before sending our drawings to the fabricators.

At the fabricator’s in Ohio, we all sat around and played with the notion of how to spin this bowl.

What type of steel should we use for the tool? Anodized? Softer? If we start with a softer tool, can we harden it later if a ton of people fall in love with these bowls and we need hundreds of thousands (I can dream, I know)? What about adding a stainless steel wire under the bead rim? Can we do that? How?

In the end, a tool was made, and bowls were spun in .090 (that’s 3mm thick copper!) which is just strong and hard enough to support the bead rim without needing the wire underneath (whew!) and a whole tool just for that application.

copper bowl, vintage copper, vintage copper bowl, pure copper, real copper, real copper bowl, unlined copper bowl, heavy copper bowl, thick copper, thick copper bowl, bowl, baking, chef, pastryThese bowls are 5qt capacity and not only are they extremely heavy duty, but they are solid copper to boot. I feel like I need to stress this because there are other copper bowls out there. But there’s a huge difference. Most of them are made in China or India (a very very few are made in Europe) and they are actually either lightweight aluminum plated with a very thin layer of copper or it is a lighter gauge of copper sheet. You can tell because the copper actually starts to chip away with use or bends easily.

If you go cheap, it’s not 100% pure copper, so you’re definitely not getting the full chemical response when whipping those egg whites or preparing the pastries.

So, we have vintage reproduction 5qt pure copper bowls (CDA 122)! Ready for you, forever.

But the best part is the handles. That’s where the story really comes to life. And you know we’re all about the story here at HC!

Not only was it important that the handle for the bowls be made in America, but I wanted copper handles. Apparently (and not surprisingly) this was also hard to come by.

Enter the annual tinsmith convergence and connections via my master tinsmith Bob, and suddenly one of my new acquaintances said: “Sure! I can do that!”

This is Tom Miller, a three-tour US Navy Vietnam Veteran and retired police officer/CSI. He works in stained glass, wood, tin, copper and even ice and sugar when the mood hits.

Another Midwesterner (he lives in Michigan – right next door to my Wisconsin abode), Tom has just lost his wife of almost 40 years and has raised his six children (whew!). When he’s not hammering on my copper handles, he’s operating a masonry restoration company.

Tom jumped in. He made the copper pieces efficiently and opened the lines of communication with the fabricators so they could figure out the tweaks directly. With a few prototypes and some small changes, suddenly an order of 30 handles was filled and these bowls were set to hit the market right as everyone is thinking about Christmas gifts (hint hint!).

It is wonderful to collaborate with another craftsman. Working with him matches our philosophy of staying with small artisans and family owned/operated American companies. I hope tons of orders come in so that Tom can keep making these lovely handles for us – and so you can have a piece of hand-worked artistry in your hands yet again as you mix up some cookies.

PS – one of the coolest things about Tom (among other cool things): check out Tom’s awesome rescue of a newborn infant during the Vietnam War!

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How to Build a Garage Shop

It’s time I admitted to my obsession. I collect tools.

As in: “Honey, for our wedding anniversary, can we get a band saw?” Or going on McMaster-Carr’s website weekly. Or begging my uncle to look for vintage tinsmithing tools at his blacksmith conventions. Or “Can we build a shop in the backyard for all my tools?” (pipe dream…)

This is a relatively recent obsession that has only been part of my life for the past…oh…three years. It got worse after I started my apprenticeship under Bob (master tin and coppersmith) because suddenly I wanted (needed?) not only modern tools but vintage tools.

And the worst/best part? The collecting never ends.

Power tools! Add-ons! Air compressors!

Do we need a mini forge…? I think we do.

Anyway, with all of these tools, and with what I’ve been able to learn at the side of so many amazing mentors over the years, it was high time to try my hand at doing as much of the fabricating that I can.

Why?

Well, besides giving me an excuse to buy MORE tools (which I totally did…it’s an investment, right?), doing most of the work myself has helped lower the cost of manufacturing, which is already high due to the fact that all my copper cookware is made and sourced in America and it’s all pure metal: pure copper, pure tin, pure iron.

Which means that whenever you now get a copper pot or skillet or lid, it’s still 100% pure and made in America. But now I’m sanding the handles myself. And drilling them. And drilling the copper out and then riveting the pieces together. And then tinning, buffing and polishing them. (Bob helps a bunch, too!)

This means I’m now the proud owner of a drill press, riveter, grinder, airbrator, and buffing and polishing wheel. And a bead blaster. And a bench sander. And a whole tinning set-up, plus the ability to make a lot of fire. And I have to make jigs to hold it all. And there’s where that anniversary band saw comes in.

Plus all the vintage tools, which I get to play with as a reward for doing some copper pots.

I love doing so much of the work in-house on the copper cookware, and honestly if I end up being unable to keep up with orders, I might be crawling back to the amazing artisans who have helped me along the way with advice, samples, and mentoring. (The guys in Ohio have been FANTASTIC to say the least.)

But I also believe that pure metal cookware and American copper cookware should be in everyone’s home. Everyone deserves a piece of cookware that is clean, healthy and made to last thousands of years. So I’m trying, bit by tiny bit, to make that possible on my end.

We’ll get there.

In the meantime, I’ll be out back, playing with tools and fire. And hoping for a tool shed. Which I will probably have to share with my husband. The other saws are his, and I need to use them sometimes. I guess he can use my arbor press if we have to share.

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Copper Cookware Interior Linings

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There’s the ongoing debate (which I suspect will never die) about what interior is better for copper cookware: stainless vs tin vs nickel vs silver. American brand copper cookware is generally made either overseas (ironically) or by small boutique artisans these days, and anyone who cooks in copper has opinions about what they prefer their copper to be lined with. This is my take on it and why, but as always, it’s just my two cents!

First of all, I am completely in the camp that lining a non-ferrous metal (copper) with a ferrous metal (iron) goes against the point of using copper. Copper (and the tin bonded with it) has a thermal conductive speed of over 380W/m K, whereas stainless is around 25W/m K. Plus, if you want something made to last, and won’t slowly rust away, having metals that don’t contain iron is where to place your bets. Copper and bronze ewers used by the Egyptians thousands of years ago and stuck in Nile mud are still found in relatively the same shape and in good condition. Meanwhile, iron cooking pots in Viking digs that date back a mere 900 years are crumbled up and nearly gone to oxidation. Granted, stainless might not oxidize quite that fast (there’s no way to know yet, considering stainless steel has only been around for about 100 years) but you get the picture. I’m all about making something that should last for millennia. (why not?)

 

Anyway, regardless of my opinion, there are four generally used and/or viable metals for lining copper cookware.

The first is silver. This stuff is amazing. It’s the fastest (that means its thermal conductivity is superb, better than copper’s (406 W/m K), and is highly efficient in heating and safe for cooking food. It bonds molecularly with the copper, and lasts a long time if you use wooden or silicon utensils. There’s mainly one problem with silver, and that’s price. Since I know my cookware is already pretty pricey for some people, could you imagine if I coated it with silver? They’d be crazy awesome and super beautiful, but probably not practical. Bloomberg’s luxury list recently popped a silver saucepan, and it’s only you know…few thousand bucks.

The second interior option is nickel. In fact, many old and vintage pieces are wiped with or plated with nickel. Many times they can be refurbished with some good cleaning and a new coat of tin, and this is probably best due to the amount of nickel allergies out there. The nickel doesn’t leach into food the way, say, lead would, but it still would be touching the food and having a slight chemical reaction with it, so if you (or your dinner guests) had any type of nickel aversion, you probably don’t want to be cooking with it. And who wants to be on the line for that type of issue? No maker I know…

Then there’s stainless, which many people like because they say it’s easier to work with. I have yet to receive an answer on why exactly that is. If you’ve got a copper sauce pan that’s 2.5mm but lined with stainless, my guess is you’re still probably hand washing (correct me if I’m wrong and you have a magical dish soap for your washer that doesn’t result in pitting your copper?!) There is some ease in that stainless doesn’t scratch like tin, so you can scrape away at the stainless lining with wire and metal. Bear in mind that stainless is sticky (so clean up is harder) instead of non-stick like tin, and eventually it may pop apart due to the huge range in thermal coefficients between stainless and copper. Or your cookware isn’t pure copper, so it may stick to the stainless without much issue.

Clearly, I’m in love with tin lining. For me, molecularly, thermally, and purely – tin-lined copper takes the cake. Because of the electron exchange that happens when tin and copper are heated together (we’re talking over 500F), the molecular bond allows the thermal conductivity properties (ie: fast!) of the copper to transfer seamlessly through the crystal structure of the tin, allowing the copper to actually work the way it is supposed to when used as copper cookware. Plus, it’s non-stick and you need far lower temperatures to achieve the same thing, so it’s green/energy efficient plus always can be re-tinned over the decades, meaning it’s renewable and sustainable and won’t end up in a landfill. Tin has its downsides, of course. With daily use and proper care, it can slowly wear down. After about 12 -15 years your copper cookware may need re-tinning, which has to be done by hand.

 

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Copper Cookware: Vintage copper cookware seams

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COPPER COOKWARE SEAMS: HOW DO THEY DO THAT?

Before CNC machines and even hand-held lathes to make copper pots, we made ‘em out of copper sheets. This meant that we were stuck using small sheets sent over (and heavily taxed) from England (even though the copper itself was mined in America) and riveting, braising, seaming and pressing those sheets together in order to create nearly all copper cookware.

Everything that was made with copper was usually required to be waterproof. From boilers to cups to coffee pots to washpans – everything held some sort of liquid. By the 1700 – 1800’s, tin and coppersmiths knew to line the cooking wares with tin in order so the copper and heat wouldn’t combine for an icky combination.

But before anything could be tinned, or considered finished at all, the sheets of copper would need to be cut, fit and joined together with seams which were then either soldered or braised together.

Because there’s few places to list these seams, and there’s buzz about vintage copper cookware out there, I thought I’d put it out in writing in case anyone wants to delve into it. I’ve learned this at the tinsmith and coppersmith apprenticeship I’m so lucky to have at Backwoods Tin!

 

The Lap Seam

This very easy connection is simply when the very ends of the metal sheet (which you’re going to bend or curve) are clipped to your seam/burr allowances. The two metal ends are then placed next to one another, overlapping slightly, and then usually soldered together.

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Example of a lap seam exterior (on a tin mug).

The Crimp Seam

Make your hand into a C shape. Do it with the other hand. Now join the “C’s”. There’s your crimp seam. The copper sheet ends are bent into V shapes that fit together and then are pressed together. Another way to make a crimp seam along the base of a copper pot is to splay the bottom of the copper into a 90” burr, and fit a burred base around the burred bottom. Hammering down the exterior base burr over the top of the copper body burred base creates another version of the crimp seam.

(this can also become a double crimp seam if you take the finished seam and then push it up against the side of the vessel, or fold it over once more)

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Crimp Seam example along the base of a vintage sheet metal copper pot.

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Exterior View of a Crimp Seam on a Copper Pot

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The interior view of a crimp seam on copper cookware.

The Cramp Seam

A lot of very old vintage copper cookware has this particular method along the base. It has been called “dovetail seam” which is one way to describe it, as it certainly looks like splayed versions of the square dovetailing done on woodworking. However, in smith-talk, that’s a cramp seam. Those were insanely hard to do. Not only was the cutting very difficult, but also matching the copper together and then braising it to essentially melt the copper together, was incredibly painstaking. It’s one of the reasons they are rare – they were harder and more expensive to make so a plethora wasn’t made. They are beautiful…but tricky!

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Example of a Cramp Seam on a copper cookware base.

So there you are! Three kinds of seams, all of which can be found on American copper cookware made the old way – sometimes more than one is used, depending on the copper cookware made. Either way, they all helped make those canteens, cook pots and beer mugs waterproof, which was the end goal after all.

{If you want to purchase the modern versions of pure metal American copper cookware, I’d be thrilled to share my copper obsession!}