Short answer? Yeah, you can-but it's not the best tool, and you gotta be careful. Let me break it down because I tried this when I was removing wallpaper from my bathroom, and here's what I learned.
First, why it works (sort of): Taping knives have a flat, sturdy blade-great for prying up loose edges of wallpaper. If the wallpaper's already peeling in spots, you can slide the edge of the knife under the peel and gently lift to peel off bigger sections. That part's handy, especially if you don't have a dedicated wallpaper scraper.
But here's the catch: Taping knives are sharp, and if you're not careful, you'll scratch or gouge the drywall underneath. I did that once-pressed too hard trying to get a stubborn section of wallpaper off, and ended up with a little dent in the wall. Had to patch it later, which was extra work. Also, if the wallpaper is super stuck (like if it was painted over), a taping knife won't be strong enough to scrape it off without bending the blade.
Pro tip: If you're gonna use a taping knife, stick to a 6-inch or 8-inch one-smaller blades are easier to control, so you're less likely to damage the wall. Spray the wallpaper with warm water and fabric softener first (that loosens the glue), wait 10 minutes, then use the knife to lift the edges. And go slow!
Don't yank or force it. But honestly? If you're removing a lot of wallpaper, invest in a cheap wallpaper scraper-it's curved to avoid scratching the wall, and it's way more effective.
