I get a lot of “special” projects in the shop – the types of copper restoration most restorers won’t take because it’s tricky or difficult or will require extra steps because it’s put together crazy. This also means I don’t always have the pretty slick copper pots to show on Instagram because my pieces are, say, 300 years old, have giant holes, or are odd shaped. I don’t mind – the challenges are always a good thing!
Anyway, I have to take out a lot of dents, especially in the thinner pieces or the oddly shaped ones. This is done a handful of ways, and all of them are done with care and light hammer strokes.
So, the first way is to put the piece on a tinner’s stake (or PVC pipe if you don’t have a stake) that fits the interior diameter. Place the piece so you’re hitting the copper directly where the stake/pipe is on the other side (otherwise you risk putting in even more dents!) and then hammer with rawhide hammers or lightly with a metal hammer.
The second way is to go in from the inside and hammer the dent out toward the exterior. Do this before you retin, and place something soft, like a towel on the other side. Using a planishing hammer, carefully tap the bulge from the inside toward the exterior.
Lastly, many things I get don’t sit true – or flat – because they are very very old or made of 1mm thick of copper or even less. The issue with these is the copper crystals have expanded so much that there’s not really a place for the “extra” metal that’s bowed in or out to go. Sometimes you can get the piece flat by belling the base in, but that’s not ideal at all for cooking. Best case (and it’s always an IF) you re-anneal the copper with a blow torch and slowly hammer the base in. Re-annealing the copper any time you have a serious dent or crushed handle is helpful, but you have to be careful not to overheat/burn the copper away (this can happen with the older/thinner pieces), and sometimes it is helpful to have a helper in the shop to hold the torch while you hammer and hold.
Each piece is different and each piece is unique with its own issues – I never know what I’m going to get, and I’ll be honest, the stuff that will fall apart over the fires are by far the hardest to fix because the control is even less and the re-tinning has to be done in pieces with a tiny blow torch. It’s a bit tricky (and probably why many restorers won’t touch the ones that can fall apart – they are hard to do and less pretty even when complete due to the methods needed to restore) but someone has to be willing to pick up that hammer, right?!
Anyway, there you go! There are YouTube videos as well of some of the methods above!