I would like to make some drainage holes in the bottom of some terracotta pots I have. I am tempted to use a drill but am not sure whether this will work and how should go about it. Has anyone ever done this?
Place your pots on a piece of large enough wood that you wont mind having a few holes in a flat and stable surface.
If you use an electric drill mostly you can set the speed.Or a battery operated one is good. Put it on 25-40% roughly. MAKE SURE THE HAMMER EFFECT IS OFF. Use a new sharp mortar drill ( cheaper than tile drill) and put water in the base- Not flooded just enough to keep the drill cool because you going to need to drill for a constant time (2-6 minutes depeing on thickness) applying slight pressure and slight tilting the drill form side to side every few moments.
If these are thick pots you will be OK. But if they are the small windows pots you have to be more gentle.. even using tile drills i have broken tiles in half.. And i have had good success using mortar drills on tiles... Just be gentle and make sure to keep the drill bit cool other wise it will go blunt and you will be drilling your whole life.
In addition to using a tile bit, I would recommend using a hand drill instead of a power one. I use mine for drilling thin panels or other delicate material.
As this works for tile, it should work for terracotta too.
I do it with a simple electric drill machine using 2mm bit. I make multiple holes in a circular form and then cut through these holes to make one hold of desired size.