remove wallpaper paste

Trying to repaint a room. Scored and sprayed the wallpaper. Most came off as expected. Most of one wall did not. Most of the wallpaper from that wall is now off but the glue is not. It does not appear to be water soluble. We tried sugar soap and metho–nothing. I am perplexed as to why this one wall is so problematic. Although it seems like a stretch I am postulating that they used construction adhesive on this wall only, for some reason. Does anyone have a way to remove mystery glue from a wall?

I’d try to sand it down as much as possible and then put down a layer of primer before painting.

It sounds like that wall was not painted/primed prior to putting up the wallpaper. Although they do sell paste remover, I’ve had success with vinegar and water. But as Hampshire suggests, if it’s only one wall, it might be a lot more efficient to just sand it well and paint/prime it.

I know you said that the paste doesn’t appear to be water soluable, but have you tried a wallpaper steamer?

We had a similar problem with wallpaper in a bathroom. It had been put up straight on the sheetrock, without primer. I tried sanding the stuff off, and it was turning into a total mess. The steamer softened the primer enough that I was able to scrape most of it off with a putty knife, followed by sponging it off with hot water with a bit of liquid fabric softener in it.