Hammering a lid out of a copper sheet

[Fredistiller]

After I posted the picture of my still, people asked my more information about the methods of hammering copper to make the lid of a boiler/thumper.

copper 4.jpg

I thought about the best way to explain the techniques and decided to make a tutorial. If you like metal work, I truly hope this will spark your interest.

I made a step by step tutorial. Step "4-hammering" has different difficulty levels to fit anyone needs and ability.
Sinking copper on wood is not that difficult, raising on an anvil adds a bit of a challenge and raising copper requires some hammer skills. Although if you follow my advice it shouldn't be impossible for a handy Harry.

English is not my mother tongue, so please tell me if I don't make myself clear.



The Material:

A copper sheet around 0.7mm (0.028") thick. A torch, a metal shear, a hole saw, a compass, 1 or 2 "rounded face" hammer (you can grind an old flat hammer), a flat hammer, an anvil or any thick flat metal surface, a thick wooden plank (cheap pinewood is okay) with a cavity of diam ~130mm & ~10mm (5.1" & 0.39") deep.

0 toolsJPG.jpg

1- Drawing:

DSC04440JPG.jpg

Think about a shape you like (dome, elliptic,...) and draw it on paper or computer. Keep the inside diameter of your boiler (or adjust your boiler to your lid if you plan to make both, it's easier). Just bear in mind that the deeper/higher you go, the harder it will be. Also hammering a lid shaped like a plate/flat dome (right part of the drawing) will be easierthan a sharp cone. An ellipse (left part of the drawing) will need the use of the three hammering techniques (see further). In all case I wouldn't go bigger than a diameter of 400mm/11.8" and deeper than 35-40mm (1.4-1.6") as it gets difficult to handle.


2- Tracing:

Once your drawing is done, measure the length from the centre to the outside with a wire or a rope (or with your software) and report it on the copper sheet with your compass. Mark the centre with an awl/nail. Add 10mm (0.39") and draw a second circle, that will be your ledge. Then draw many circles, like you would draw a "target". And finally, draw a line from the centre to the outside. The face with the drawings will be the inside of your lid.

tracingJPG.jpg

3-Cutting:

With your metal shear cut first approximately at 10mm (0.39"), then precisely on outside of your future lid. Smoothen the sharp edges!

cuttingJPG.jpg

And then, congratulate yourself and take a deep breath, you are now ready for the real stuff...