I make a lot of spaghetti sauce to use and freeze. Each time I stir up a batch of sauce I clean and store the 29-ounce cans the crushed tomatoes come in. Ofttimes, when I upcycle the cans in projects I will need to add holes of some kind to them.
The easiest way I have found to do this is to fill the can with water and freeze it first. This gives me a solid mass to punch into, but is also easily removed. (Melted in this case.) The one drawback is the flat bottom of the can becomes curved by the pressure of the freezing water, lowering the level of the water several centimeters. The bottom is easily flattened back out with a hammer.
I am making a flower rack out of upcycled cans and some wire baskets I found at the local thrift store. I will need to punch at least four drainage holes in the bottom of each can, and also two side holes for a leather hanging strap.
A common Philips screwdriver is perfect for punching the holes.
The bottom of the can is easy to puncture, the sides a little trickier because the round can is inclined to roll. I find grass the easiest grounding surface. Punching holes into the can with the screwdriver assures the sharp edges stay inside the can.
When I’m finished with the hole-punching I turn the cans upside down and let the ice melt and drain. Part II of my project will be posted tomorrow.