Ok folks, it's DIY time.
After a lot of research on this site (thanks guys!) and elsewhere I decided to try my hand at re-tinning a handful of copper pots I picked up at an antique store. While I was able to get enough information to get started, 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 that doesn't want to pay $6 a square inch to have a pot re-tinned and isn't afraid of a little molten tin!
First off, while your results definitely won't be as good as having a pro do a hand wiped tinning, it will most 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!
Things you'll need
- pure tin (got mine at rotometals)
- flux (I used sal ammoniac/ammonium chloride, I'm going to try Ruby Fluid next)
- muriatic acid
- plumbers torch or propane turkey fryer
- plumbers wad (I used some old jeans, several layers sewed together and soaked with tallow)
1) Clean that old pot/pan - The pots I got had a great patina on them, but I'm planning on cooking with them for decades to come, so 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 right off and they started looking bright and shiny. Then 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 on the inside. I scrubbed until there was no more verdigris (green copper oxide) to be seen). Lots of copper showing through and overall very clean.
2) Pickle that pot! - Next up was a soak in a 5 gallon bucket with a bottle of muriatic acid (you can get this at a hardware store) and some water to dilute it. CAREFUL, this is acid, so use gloves and protect your eyes from splashing. The acid will eat away any left over carbon build up, grease, and will soften/eat away at the dull tin. After an hour I took out the pot and gave it a good rinse, and a final brillo scrub inside. Now it was ready to get a fresh coat of tin.
3) Tin that pot! - I sprinkled some powdered sal ammoniac on the inside of the clean pot and brought it outside (DO NOT DO THIS INSIDE). I had a turkey fryer as a heat source, and put my pot on there, using a medium heat. HAVE A RESPIRATOR AND LEATHER GLOVES. The sal ammoniac 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, so use a mask. The sal ammoniac (ammonium chloride) acts as a flux so that the tin will stick to the inside of the pot. 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 on there. Swirl the molten tin around, sprinkle a little more sal ammoniac in there (clouds of smoke!), then rub the molten tin around with your plumbers wad (be sure you have gloves on). You may have to heat the sides of the pan separately to get the copper hot enough for the tin to bond there. Trial and error will play a part. As you are heating you can actually see when the tin melts, as it starts to get shiny and change color where the heat is applied.
4) Repeat - My results were mixed my first time around, but the inside of the pot ended up fully coated in tin. Used way too much tin the first time, so it isn't smooth, 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. Also, a little heat goes a long way, so don't use too much heat or you'll end up burning your wiping cloth and then burned bits may keep some areas from bonding. A plumbers torch would have been handy for more accurate heating (there's always a next time). Worst case scenario you just 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 separately.
For someone without any experience other than googling for a couple hours, I have to say 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. There are plenty of amazing quality old copper pots out there that have been relegated to antique display items. With a little elbow grease and a little effort you can bring them back to their former glory!
Beware, once you realize that you're capable of bringing back these old pots to like new functionality you might get addicted. At last count I'd picked up over twenty or so grungy looking old copper pots, and made them shiny and new again!
On the plus side, your family and friends will love you when you gift them the best piece(s) of cookware they will ever own.
I'm happy to share my experience, links to other resources, advice, and detailed pictures if anyone wants them. It's probably much easier to just buy a pot new or pay someone to refinish an old one, but sometimes it isn't about what's easy.