I'm looking to do a DIY installation for a mini-split air conditioner in my garage and I need to drill a precise 2.5" hole at a 15-degree downward angle through an exterior concrete block stucco wall that's 8 inches thick. I have both a cordless hammer drill and a high torque corded non-hammer drill at my disposal.
Is it possible to achieve this using a diamond hole bit with my corded drill, or will I need some specialized tools given the hole size, the wall thickness, and the angle? My plan is to start by drilling a pilot hole at the desired angle with my hammer drill using a masonry bit that matches the pilot bit size in the hole saw. Then, I'd drill from outside in halfway along the path of the pilot hole. Lastly, I'd switch to the inside and continue drilling to meet the other side. Does this sound like a good approach, or does anyone have better suggestions?
2 Answers
If your wall has standard hollow blocks, you might want to try drilling two straight holes—one from the inside and one from the outside. Just make sure the outside hole is slightly lower than the inside one. This way, you'll get your piping angled correctly without too much hassle!
When I had my AC replaced, the technician just used a big ball-peen hammer and made a clean hole around 2.5 inches wide. If you can manage the angle, that might save you a lot of drilling hassle!
That's a clever idea! Any tips on how to find and center over a hollow spot in the block?