Originally Posted by Carl Froehlich
Gently tap this out flat with a small ball peen hammer on an anvil.
If you do that you will stretch the metal. Do NOT hammer this between steel and steel. if you squish aluminum between 2 things that are harder then something will have to give, and it will be the aluminum. So you need to hammer on wood, or hammer with a nylon hammer. You have to make sure your skin is not the softest thing in the equation.
I have done some English wheel work in aluminum and have had a bit of training - enough to be dangerous. When panel beaters are hammering out dents, then will hammer "off-dolly" to avoid stretching - that means they put the dolly on a low spot and they hammer (or slap with a slapper) on an adjacent high spot. This forces the metal together, shrinking it. The sound is a dull thud. If they hammer "on-dolly", they are trying to bring up a low spot i.e. stretch. To figure out of you are off or on dolly you tap around until you hear the right sound. Dull thud for off-dolly, and "tink" high pitched metal on metal sound for on-dolly. "tink" is the sound of metal stretching. Do that to your skin and you are sunk. Also, 2024 can't really be hammered that much or it cracks. I've never heard of the spoon trick - that's awesome!