Why does my nail gun make the nails spark?
Your gun is sparking for exactly the same reason as the sparks you get sometimes when you whack any other steel nail hard, with an ordinary, hard-headed carpenter’s hammer. You’re trying to drive 3-inch nails with it, and that takes a lot of force. You are not seeing it with the brad and finish nailers because they don’t drive the smaller nails with as much impact. You’d only need to be concerned about the sparks if you were working around something flammable. Just keep your eye and ear protection on you when you’re using it, and enjoy the work it’s saving you.
