Short answer? Yeah… but only if you're doing tiny stuff. Let me explain-because I tried this once, and it was a nightmare.
Putty knives are usually small (2-4 inches), thin, and flimsy. They're made for things like filling nail holes or scraping off old paint-not big drywall seams. If you try to use one for embedding tape? Good luck. The blade's too short to spread compound evenly, so you'll end up with lumpy seams.
And since it's flimsy, it'll bend when you press down-tearing the tape or leaving gaps. I tried taping a 2-foot seam with a putty knife? Took me 45 minutes, and it still looked terrible.
Now, if you're just patching a super small hole-like a nail hole the size of a pencil eraser? A putty knife might work. But even then, it's not ideal. Taping knives have sturdier blades that hold their shape, so you can spread compound smoothly. Putty knives? They're like trying to spread peanut butter with a plastic spoon-messy, uneven, and frustrating.
Here's the thing: Drywall's all about smoothness. If you use the wrong tool, you'll end up sanding for hours (or worse, repainting because the seams show). Save yourself the headache-just grab a taping knife. It's not expensive, and it'll make your project 10x easier. Trust me, I've been there.
