Wallpaper Removal

That's what I'm afraid of. It's a 2ft x 5ft section over a solid oak mantle/fireplace. It's strange....all the plaster walls are white, but this 2x5 section is gray but is just as smooth as the white. You can feel no physical difference where the two colors join. But I think possible they failed to prime this section prior to paper installation. All the other is coming off rather easily other than the time and labor, lol, since it's 10-12ft high and a very large room. Ah....and so many more to go, lol .
Got a feeling I'm just gonna have to spred mud on it and try to smooth it out. Most of this area will be covered by a large mirror. Only about 2" in each side is visible.

I'm gonna coat that 2x5 area with Kilz Original..... I am gonna use Guardz on all the walls in this room as ChrisN advised. So I guess Guardz first, then Kilz Orig on this area then paint. I'm pretty frustrated with this job. It was bad enough to have to strip 96 years of this nasty crap...now an area I can't even clean up. All I can figure is the PO's for past 96 years have been very lazy to let this crap pile up and just keep painting over it. Such a shame with large rooms, tall ceilings and beautiful wood to have all this crap on the walls. Sorry for the "b" session, just getting tired. This is room 5 and each one has had a different set of problems, lol. :furious: Oh well...hopefully all this hard work will pay off. The goal is to see beautiful painted plastered walls. Sure is tough getting there, lol.

Thank you for your advice and Chris as well. I'd probably already have jumped off the bridge at this point.

No, actually I did not wear a mask or respirator. The thick painted over paper sheared off in strips using a putty knife (I do less damage with it vs a paper scraper) with very little flaking and virtually no dust (amazing since I'm not the greatest housekeeper, lol). In the other rooms, I did wear a mask when sanding. I had to do a lot of wall repair and three of those walls were "painted over paper". I used mud and sanded. However, I used 123 primer (water based) so I hope I don't get bubbles, lol. If so, those three walls need stripped anyway. I've getting a little more brave and confident as I finish each room, lol. Hopefully by the time I make it upstairs, I'll be a pro.