How to build a pair of dumbbells?

Necessary elements: 

• Metal tube that allows curtain = 50cm with smaller diameter 2cm
• Sierra Handheld metal
• Poxipol Or other glue
• Pvc largest -Caño 11 cm x20 cm diameter
• Caño Boy pvc 2 cm in diameter x 20cm
• Cement (1kg), sand (3kg), water (1/2 liter)
• Container 5 kg or more (a can of water for example)
• 8 DVDs or CDs that do not serve or are on
• '' foam 'in measures of leave to you maybe have thick or thin and will require more or less of this. the width is 15 cm, can be replaced with cotton or cloth.
• leather 15 cm x 30 cm
• tape black electrical (optional)
• pen