My grandfather showed me this technique, when I was young. He told me the story of how he had forgotten to bring a spoon to work, for his lunch. He was able to make a spoon out of scrap metal and use it to eat. This technique is useful in making spoons, bowls, and other curved shapes out of sheet metal.
Step 1: Safety Equipment
Safety glasses are a must for any project.
You will be working with sheet metal that can be sharp, especially after you cut it, so a good pair of leather gloves should be worn.
There will be an extended amount of time hammering, so you will want to protect your hearing with some ear plugs.
Step 2: Materials
You will need a block of wood. I used a piece of 2x4. You want the wood to be a soft wood so you can make a dent in it with the ball peen hammer. I used pine. For your metal you could use almost any sheet steel. The softer and thinner the steel, the easier it will be to form, but the softer metals are more prone to cracking or tearing during the process. I used some 16 gauge aluminium and some thin aluminium from a can.
Step 3: Tools
A ball peen hammer. I used a 16 oz. You may want a smaller hammer for small shapes or a larger hammer for larger shapes. Something to cut the metal like sheet metal shears or tin snips. Something like a Sharpie to mark on the sheet metal. And some sand paper to smooth out the edges.
Step 4: Mark Out the Shape You Want
Mark out the shape you want on the metal. It is easier to make changes before you cut.
Step 5: Cut Out the Shape
Use care when cutting out the sheet metal. The edge can be very sharp.
Step 6: Prepare the Block of Wood
The block of wood needs to have a dent in it to act like the mold for the steel. Think of the hammer as the inside of the curve and the wood as the outside. Place the wood on a sturdy surface and hit it a few times to make a concave dent.
Step 7: Hammer
You want to put your metal over the dent and hammer it with the ball end of the ball peen hammer. Lots of little hits will make your piece of metal take shape. Move the metal around to get a smooth bowl shape. This takes patience and can be meditative. Just make sure you use hearing protection.
If you want to make a long curve, make a dent at the end of the wood. This is useful in making a handle for a spoon stronger than just a flat piece.
Step 8: Smooth Out the Edges
Once you get your metal shaped the way you want it, smooth out the edges with some sandpaper.
Step 9: Not Really a Step But Check Out the Blur
I was taking video of this project and thought the screen shots of the blur before the impact and the focus after the bounce were cool. These two images are the same hammer taken 1/30th of a second apart.
Step 10: Video
As usual, I made a video.
Thanks for watching and enjoy.