Set out more than one bucket to speed up the process when multiple weights are needed. Use only buckets that taper upward, or have smaller diameter bottoms than tops. Paint the insides of the buckets with concrete release agent.
Pour dry, fast-setting cement mix in a concrete mixing container. Stir in water, using a shovel or hoe. Follow the manufacturer’s directions regarding how much water to use. A thick, soupy concrete consistency should result.
Set a bucket on a scale. Pour in concrete until the desired concrete weight is reached. Pour any remaining buckets to the same level. Tap the buckets to allow the concrete to settle.
Embed some kind of handle in the top-centers of the poured concrete buckets. Options include industrial steel or iron handles, iron loops or bent pieces of rebar. The embedded sides of the handles should undercut the concrete to prevent them from being pulled out after the concrete sets. Place sticks through the handles and balance the ends on the lips of the buckets to hold the handles in place while the concrete hardens.
Allow the concrete to cure for about 40 minutes. Remove the sticks. Turn the buckets over and slip them off of the cured concrete forms.