A Systema Punching Bag
I have a 20L dry sack I use for washing my clothes in while traveling.
I discovered that when filled with water and clothes, the dry sack makes a good punching bag. Plus, punching the clothes forces the water through the fabric, giving a pretty good wash.
The wet fabric acts as a damper on the water, which makes the bag feel a lot like flesh.
My dry sack is made of 420 denier urethane coated fabric, but I think the heavier duty PVC coated fabric type would be better as a punching bag.
Repeated punching has put stress on the seams so that they are no longer watertight. I fixed that by lining my dry sack with a heavy duty garbage bag, making sure to leave plenty of plastic rolled up at the bottom so the plastic doesn’t split under impact.
When lined with a garbage bag, a top opening duffel bag works just as well as a dry sack.
For a more permanent punching bag, I use a cheap Dacron fiber pillow instead of clothes. Dacron fibers are often used for stuffing furniture and for insulating clothes. When soaked with water, the result is something that behaves a lot like a gel or flesh.
It’s important to drive any air out of the bag as you close it. You dont want the bag completely full of water.
I’ve hung my bag on some heavy duty hooks againt a concrete wall.
At first, I was punching the bag, but now I aim to punch the wall through the bag. There’s a satisfying sound the wall makes when I punch right.