Ok folks, it's DIY time.
After extensive research on this site (thanks guys!) and elsewhere I tried my hand at re-tinning a handful of copper pots I picked up from antique store. I was able to get enough information to get started, but I wouldn't say there was enough to make me feel confident about what I was doing.
Thought I would share my experience for anyone else out there with an interest in bringing an old copper pot or pan back to life that doesn't want to pay $4-6 a square inch (plus shipping) to have a pot professionally re-tinned and isn't afraid of a little molten tin!
Why copper? Well, it is the best conductor of heat of any metal used for cooking, 25 times better than stainless steel! That means once the heat hits the pot/pan it heats evenly and immediately. You'll use less heat (I can boil on medium), heat is distributed to the entire pot (no hot spots), and heating will be more responsive. These pots/pans excel at anything that is simmered due to their precise temperature control. Plus, copper just looks amazing!
Why a tin lining? For those that don't know, the purpose of lining a copper pot/pan with tin is so that acidic foods (tomato based sauces etc) don't react with bare copper and produce copper oxides, which can make food taste strange and if left for long periods of time can lead to mild poisoning. This copper oxide is also called verdigris, and is that green stuff that you see on the Statue of Liberty, or other copper exposed to the elements. Many new copper pots/pans have a stainless steel lining, which is more durable, but more prone to sticking and less conductive than tin. All really old copper pots have tin linings, and those are the ones you're likely to find sitting in antique shops or thrift stores because they look real grungy and scary to cook in (until you bring them back to life!)
What do I look for in an old copper pot? If you find an old copper pot, pay attention to the thickness of the walls and the overall weight as these indicate the quality of its construction. Thickness generally ranges from 1mm (more of a display piece) to over 3mm thick (a serious professional/hotel kitchen item). The heavier the pot/pan, the better. It should feel hefty and solid when you pick it up. Really old copper pots often have a brazed "dovetail" or "finger" joints where the hammered copper sheet was joined together, later models were made using industrial machinery to spin or form them without joints. If you find an old copper pot on craigslist or ebay, be sure to ask how much it weighs, that'll give you a good idea if it's worth what they are asking.
Can I do this? While your results definitely won't be as good as having a pro do a hand wiped tinning on the first try (there are several places out there that will do this for you, East Coast Tinning and Rocky Mountain Retinning to name a few), it will definitely be functional. In the end, I decided that since my pots are really old hand hammered and dovetailed pieces of art, I didn't mind if my tin lining isn't totally smooth. These are items that can take a beating, mine are at least 100 years old, and still have a lot of life left in them. A few bumps and lumps just add to the charm!
Step 1: Gather Your Supplies!
Things you'll need:
Preparation - Cleaning the pot
- Distilled white vinegar (the cheap kind for cleaning)
- A non-scratch sponge (for the outside of the pot)
- Fine steel wool/Brillo pad (to clean up the old tinned inside of the pot)
- Bar Keepers Friend (also amazing for cleaning stainless steel, old rusted bits, or other metals)
- * muriatic acid (also called hydrochloric acid) This may not be necessary if you get the item REALLY clean with the above items
- Stay Clean flux by Harris has been suggested by a pro (thanks housecrockery)
- I have used sal ammoniac/ammonium chloride previously (working okay, LOTS of fumes)
- Ruby Fluid is the other alternative I've used with some success
- plumbers torch (brazing torch)
- use gas & blown air, or a big petrol / paraffin blowlamp.
- Don't use an oxy-acetylene as it burns too hot. You need low/medium disbursed heat.
- I got mine at rotometals
- 1 lb is more than enough to do over a dozen pots/pans
- Only use pure tin (or 99.99% pure tin). Don't use tin based solder, which may have lead or antimony in it.
- Traditionally made using a thick type of cotton cloth called moleskin (think the stuff they made construction work suits out of)
- Fiberglass wadding also works (thanks housecrockery)
- I have used some old jeans, cut up palm sized sections, then sewed three or four layers tightly together and soaked with warm tallow (the above probably work better)
See instructions for making one here (plumbers tools)
Step 2: Clean It Up, Inside and Out!
The pots I found had a huge patina on them, really gorgeous. This is great if you're displaying them on a wall, but I'm planning on cooking with them for decades to come and want them to shine like new. I started by soaking the pots in a hot solution of water/vinegar. After half an hour or so much of the years of grime/neglect came off and they looked bright and shiny.
Next some Bar Keepers Friend and a sponge did the rest. They looked great on the outside, but still some grunge/verdigris/dull tin on the inside. Next step was a brillo pad or fine steel wool on the inside. I scrubbed until there was no more verdigris (green copper oxide) to be seen. Lots of copper showing through the worn tin lining and overall very clean.
Step 3: *OPTIONAL - Pickle (degrease) That Pot, in Acid!
** This may be overkill, and is likely not needed if you did a great job of cleaning in the previous step. **
Next up was a soak in an acid pickle to degrease the pan, and get it spotless. Always use a plastic container, a 5 gallon paint bucket with a lid works great. First fill the bucket with water (I used three gallons of water), followed by a bottle of muriatic acid (you can get this at a hardware store, I used a full gallon).
- PRO TIP, ALWAYS pour the acid into the water ! NEVER NEVER add water to the acid ! (tip of the hat to Jake on that one).
CAREFUL, this is acid so even if it is diluted it is still nasty stuff, so use gloves and protect your eyes from any splashing when you dip the pot in or take it out. Always be near a water source in case you do splash yourself and need to rinse off.
The acid will eat away any left over carbon build up, grease, and will soften/eat away at the dull tin that is left on the inside of the pot.
After an hour I took out the pot and gave them a good rinse, the muriatic acid will change the color of the copper to a light pink (unless there is lots of patina and gunk still stuck on there, which sometimes discolors it a bit).
Once the outside has been cleansed of acid, I gave mine a final Brillo scrub on the inside to get and loose bits, it some places it gets down to the bare copper, which is fine.
One more rinse and now it was ready to get a fresh coat of tin!
Step 4: Tin That Pot!
First, coat the inside of your pot/pan with the flux of your choice.
To avoid getting tin on the outside of your pot you can put "whiting" on there (powdered chalk with a little water works I'm told). I personally skipped this step and didn't have too many problems with dripping tin on the outside.
- PRO TIP - To get the tin flowing over a wide area more easily you can also pre-heat your copper pot in an over at 450. If you choose to do this I wouldn't apply flux until the next step when you are out of doors. I've done this with a pre-heat and without, both turned out fine.
SAFETY FIRST. Wear a long sleeve shirt, long pants, and closed toed shoes. The pan will be really hot, as will the tin and you don't want it touching your bare skin. HAVE A RESPIRATOR, EYE PROTECTION AND LEATHER GLOVES. If you use sal ammoniac as your flux it will create a thick white smoke when heated, and from what I hear it will rust anything it touches. Also, not good to breath in since it is corrosive, so use a good respirator mask.
Bring your fluxed pot outside (DO NOT DO THIS INSIDE ON YOUR STOVE). I used a propane turkey fryer as a heat source on a medium heat. Put your copper pot on there and slowly heat it.
- PRO TIP - Since copper both gains and loses heat quickly you can create a basic brazing hearth using fire bricks. Just lay them our around the flame of your propane burner, google around and you'll get the idea.
The flux allows the tin to stick to the inside of the pot.
- If using Stay Clean, watch for it to start to get a little dark on the metal while I'm over the fire, and then start spreading on the tin
- If using Sal Ammoniac, once the white smoke starts billowing throw in a small piece of tin, or rub some tin bar around the bottom of the pot.
If the pot is hot enough (456 degrees or so) the tin will melt right away and turn liquid. Swirl the molten tin around and rub the molten tin on the inside of the pot/pan with your plumbers wad (be sure you have gloves on). You can also use tongs to hold the plumbers wad/wiping cloth so you don't have to get your hands anywhere near the hot pan, probably not a bad idea.
You may have to heat the sides of the pan separately to get the copper hot enough for the tin to bond there. Where the handle meets the pot will also require additional heat (as the handle acts as a heat sink).
Trial and error will play a part. As you are heating you will see when the old tin lining melts, as it starts to get shiny and change color where the heat is applied. Know that you can always cool the pan down, clean it, flux it, and then remelt the tin. It took me a couple of tries to get it right.
You can let the pan cool down naturally, or use the assistance of a 5 gallon bucket of water. Be careful not to dunk the hot copper into cold water immediately, as this could warp your pot/pan. I generally scooped up a little water, rolled it around the inside of the pan, and then scooped up some more to slowly cool the pot before fully submerging it.
Step 5: Try, Try Again
My results were mixed my first time around, but the inside of the pot ended up fully coated in tin (except for a few little spots on the upper edge, visible in this picture).
I used WAY too much tin the first time, so the finish is a bit lumpy, but it's ready to cook in now! I got better with a little trial and error over time. I had to move the pot around, and heat the sides to get the tin flowing.
A little heat goes a long way, so don't use too much heat or you'll end up burning your plumbers wad/wiping cloth and then burned bits may keep some areas from bonding. A plumbers torch would have been handy for more accurate heating.
Worst case scenario you start at the beginning and do it all over again. In fact, on a few pots I did the bottom very successfully, but the sides not as well. I just went back and scrubbed, pickled, and rinsed before going back to do the sides a second time.
For someone without any experience other than googling for a couple hours, it was a lot easier than people made it out to be on the internet. Use caution (gloves, long shirt/pants, respirator) and you'll be fine.
Step 6: Lets Talk Tops.
If your pan is old enough to need re-tinning, the matching lid was probably lost long ago.
A matching copper lid would be awesome, and can often be purchased online for about the price of a used copper pot ($30-60).
A functional and modern solution is to use a lid made of silicone. You can find various sets online (one example, 7.5" small suction lid, 9.25" medium suction lid, 11.25" large suction lid), and they cover nearly any size pot you'll find. You can also find single sizes (Charles Viancin makes ones shaped like lillypads or sunflowers), or even fancy silicon/glass tops. They work really well if you're cooking with an old irregular copper pot, and are inexpensive. As a bonus, you can use these silicone lids on top of mixing bowls etc instead of saran wrap (hurray for the environment!).
Step 7: Care for That Pot!
You've got yourself a nicely tinned pot/pan, now what?
- Never heat tinned copper empty. Be sure that there is something (water, vegetables, etc) in the pot before you put it over heat, if you do heat the pan empty you run the risk of overheating and melting the tin.
- Don't use high heat. Copper pots and pans excel at anything from a simmer to a sauté, but high heat searing isn't their specialty (that's what cast iron is for).
- Use wooden utensils. Your tin lining will last much longer if you use wooden (or plastic) utensils. Tin is a fairly soft metal, so stainless steel utensils can/will scratch the lining much more quickly. That being said, I've read several blogs of people from India/Pakistan that put their pots through incredibly hard use using metal scrapers and pot scrubbers daily. In those cases they talked about someone coming and re-tinning their pots each year.
- Bar Keeper's Friend to keep it shiny outside. Some people love an aged patina on their copper, and this develops quickly just from heating and daily use. If you want your copper to gleam all it takes is a sponge and some Bar Keeper's Friend to get it sparkling again. A half a lemon with coarse salt also works to remove tarnish, or spread tomato paste/ketchup on the outside, wait a few minutes and wipe it off.
- Wright's Silver Cream to keep it shiny inside. The tin lining will dull over time as it oxidizes, first to a flat grey, and darkening further as time goes on (years and years). This does not effect it's abilities in any way. If you want your copper pot shiny inside and out, you can use Wright's Silver Cream on the tin inside to get it back to that shimmering silver appearance.
- More than a quarter sized area of bare copper showing through, time to re-tin. Once you've successfully re-tinned your old copper pot or pan you have many years of great use ahead of you. Sometime down the road, say 5-15 years from now, the tin may start wearing thin in places from scrubbing inside clean with steel wool, using metal implements etc. The general rule is that if there is an area larger than the size of a quarter showing through you should re-tin.
Step 8: Final Thoughts
There are plenty of amazing quality old copper pots out there in thrift shops, antique parlors, estate sales, and on the internet that have been relegated to sitting around as old-timey kitchen display items.
The intense patina and suspect scratched lining make many people afraid of ever using really old copper pots to cook in. With a little elbow grease and a little effort you can bring them back to their former glory!
Check out the price of a new copper pot (sites like Sur la Table have really nice ones) and you'll see why this is such a great DIY activity. For around $50 I've found many really heavy old copper pots, often with 100 years or more of daily use and history behind them. With only a few tools, some free time, and a little trial and error you can have a set of pots/pans that will rival those of the best chefs in the world, for the price of just one fancy new copper pot/pan!
Beware, once you realize that you're capable of bringing these old copper pots back to like new functionality you might get addicted! At last count I'd picked up over twenty and made them shiny and new again!
On the plus side, your family and friends will love you if/when you gift them the best piece(s) of cookware they will ever own (spread the love y'all).
Step 9: Links to Other Resources
It's only right to credit all the places I found information from before I got started , so here they are;
- Start to finish hand tinning (in Italian, but you'll get the idea)
- Old-school coppersmith hand tinning a pot (he makes it look easy)
- Another hand tinning video
Where to get supplies
- Source for pure tin
- Stay Clean Flux by Harris
- Sal Ammoniac (Ammonium Chloride) Flux
- Ruby Fluid Flux
New Copper Pots Getting Made
- A look at how copper pots are made and tinned new
Fancy Antique Pots
- Site selling really nice old copper, with interesting info
Old Timey How-To Books!
- Instructions for tinning I found on google books
- Instructions for making a plumbers wad/wiping cloth on google books
Step 10: Take Your Tinning to the Next Level!
A new and improved second step to tinning was published by Mr. Buscrendore of Leipsic in the Journal fur Fabrik, manufacture, und Handlung in October 1799. Yeah that's right, 1799!
He really drops some knowledge, so below is his full text, with the second tinning step in bold.
"That copper and brass vessels cannot be used with safety in cooking victuals or for holding articles of food, and particularly those which contain acids, is well known.
It is also well known that the tinning applied in the usual manner is not durable, being soon worn away by cleaning, and on that account must be frequently renewed. Some, therefore, have proposed enameling for kitchen utensils of copper ; which, indeed, would answer exceedingly well, and be much safer for the health than impure tin mixed with lead, often employed for tinning ; but, unfortunately, enamel is too dear, and readily breaks when the vessel receives the least blow ; which cannot al ways be avoided.
The following process for tinning is attended with no danger from poisonous ingredients, as no lead is used in it; the tinning, too, is exceedingly durable, adds strength to the copper vessel and secures it from the action of acids much longer than the common tinning.
When the vessel has been prepared and cleaned in the usual manner, it must be roughened on the inside by being beat on a rough anvil, in order that the tinning may hold better, and be more intimately connected with the copper. The process of tinning must then be begun with perfectly pure grained tin, having an addition of sal ammoniac instead of the common colophonium.
Over this tinning, which must cover the copper in an even and uniform, manner throughout, a second harder coat must be applied, as the first forms only a kind of medium for connecting the second with the copper. For this second tinning you employ pure grained tin, mixed with zinc in the proportion of two to three, which must be applied also with sal ammoniac smooth and even, so that the lower stratum may be entirely covered with it.
This coating, which by the addition of the zinc, becomes pretty hard and solid, is then to be hammered with a smoothing hammer, after it has been properly rubbed and scoured with chalk and water, by which it becomes more solid, and acquires a smooth compact surface.
Vessels and utensils may be tinned in this manner on both sides. In this case, after being exposed to a sufficient heat, they must be dipped in the fluid tin, by which means both sides will be tinned at the same time.
As this tinning is exceedingly durable, and has a beautiful color, which it always retains, it may be employed for various kinds of metal instruments and vessels, which it may be necessary to secure from rust."