I recently bought a weight set, but it only had 100 pounds. For dead-lifting and certain exercises I decided I'd needed more weight. Being frugal I searched online for a cheap used set, but most were 100 dollars or more. I decided to make my own since concrete is pretty inexpensive and the weights I bought were just the concrete variety as well.
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Step 1: Item List
$11.99 for approx 80 pounds
About 0.14 cents a pound not including tax. (This includes the mold. Second set will be cheaper.)
What you'll need:
(I bought the least expensive at 30kg and used 1 and a quarter bags)
-18" Plant pot saucer_$6.99
(Could also use a bucket, water bottle or any other rounded mold. It should be over two inches in thickness)
(Doesn't have to be pvc. It should be as large as you'd like the weight opening. I used whatever was lying around.)
(Again, used what I already had. I recommend heavy duty bags or tripling them up).
Paper grocery bags_$0.00
(Old cloth, towel or other material that can soak up and retain water)
Step 2: Mixing and Adding to Mold
1.Place the bag of concrete in your doubled heavy duty garbage bag (You can skip this step and and use a large bucket if you have one.)
2. Cut it open and pour out contents (while still in the garbage bag)
3. Add water (approx 3-4 liters per 30kg bag)
4. Close the bag with your hand and slosh around with your other hand until mixed.
5. Add it to your mold and then shake the mold (Make sure your mold is over 2 inches thick. Shaking ensures more even distribution. You might want to scrap the top with a flat object until even .)
6. Cut your PVC pipe and press into the center of your mold. (There should be a portion of it still visible above the concrete)
Step 3: Curing
7. Place a wet grocery bag or towel over the mold and keep it damp.
8. After 24 hours remove from the mold and continue to place the Paper bag or towel over it.
(Use pliers to shake the pipe out)
9. let it cure (Sit) for 2-3 days. Continue to keep it damp.
(Concrete doesn't dry, but cures. This means it bonds together over time if it's kept damp. If it dries too quickly it will become brittle and crack).
10. Continue to let it dry without dampness for another day or two.
Step 4: Finishing
11. You now have some weights
(You might want to add some duct tape or PVC tubing in the center opening so it doesn't scratch your bar. Another thing to consider is adding concrete fibers or shredded nylon rope to the mix for more strength )
12. Add a cover
You can also add some kind of covering to keep any dust from the concrete inside. The image is a quickly done garbage bag and duct tape cover with PVC in the center.
Have fun lifting.