Drilling into stone wall with plaster on top

Question

I'm trying to hang a curtain rod. The wall is irregular stone, with plaster covering it. I have masonry bits, a drill, and an impact driver (no hammer drill, though I may be able to borrow one).

When drilling, the bit is wandering instead of drilling in (probably due to the irregular stone not being perpendicular at this spot to the hole I'm trying to drill). Is there a recommended way to get the hole started, so the drill bit stays in one place? Some kind of center punch or similar which I should be using? I tried just starting with a smaller bit, but it's still wandering around the stone instead of biting.

Answer 1

I have found mounting a scrap piece of wood to use as a guide helps drill through the wood and place the bit in the hole so you have exact alignment, use a couple of screws to hold the board in place not screwed tight but create a divot from at least 2 screws 3 is better. Now press the board tight and use your masonary drill bit (hammer drill will make this go much cleaner and faster so borrow one if you can). usually you only need to drill in about a 1/8 to a 1/4" and the hole will then guide the bit. Remove the board and finish drilling the hole and then patch the divots. I have done this without creating the divots but I am a really big guy and will still usually create at least 2 so the board dosent shift.

Answer 2

You'll need to anchor the bit rigidly as you begin, or you'll need to use a punch to create a centering divot, as you suggested. This action is one of the benefits of a rotary hammer.