I need some help figuring out what went wrong during my attempt to drill through my home's exterior wall for an Ethernet cable. I thought I'd done everything right: I turned off the breaker, checked for studs, and even cut a small hole to peek behind the drywall. I used my 18V Milwaukee drill with a standard twist bit, thinking it would handle drilling just a single 3/8" hole in brick and other materials.
I took my time, drilling in 30-45 second bursts and even cooled the bit with water. However, out of nowhere, I started noticing smoke and the smell of fire! I quickly wet the area and called 911. Luckily, the fire department declared everything safe with no damage. However, I'm still puzzled about what I did wrong. Would a hammer drill have helped? Were my bursts too long? Even with cooling the bit, should I have cooled the hole with air? What could have caught fire? I'm hoping to get some advice for future projects so I don't make this mistake again!
3 Answers
A dull or the wrong type of bit is probably what caused the problem. When a bit can’t cut properly, it just rubs against the material and creates a lot of heat. Switching to a good masonry bit would make a world of difference. Remember, sharp bits are key!
You definitely need to use a hammer drill function for this kind of drilling. Your wood/metal bit likely dulled out really fast on the brick, which meant you were just generating heat without any actual drilling progress. A masonry bit would do the trick much more effectively.
It sounds like you built a friction fire! Using a standard twist bit on brick generates a lot of heat, and once that bit gets red hot, it can ignite nearby materials. You should really be using a carbide masonry bit with a hammer drill for work like this. That’ll cut through the masonry better and keep temperatures down. Also, always drill at a slower speed to minimize heat buildup.
Definitely! And make sure to drill through mortar joints where possible; it can save your bit's sharpness for the actual brick.
Totally agree! Once you're through the brick, switch to a wood bit to finish the job. It should save you from overheating!