Have stripped the wallpaper from my two bathrooms. Underneath the wallpaper was the green board used in bathrooms for moisture. However, when I was stripping the paper I accidentally ripped some of the green board paper. What is the best way to repair this? I guess I would fill in all the surface holes with spackling and then sand lightly with a 300 grit paper. (Just build it up.)
Am I correct or could you suggest a better method for prepping the surface for a paint finish.
First, you need to prime the affected areas, the entire bathroom is a good idea. Use Kilz Oil Base as the primer. This will seal the green board's paper face and keep it from bubbling. Plus, the primer will make the imperfections easier to see.
Now you can do the repair(s). I like to use a setting type of <a href="https://www.house-painting-info.com/joint-compound.html">drywall compound</a> for most repairs. It is a powder that dries quickly. You can also use regular drywall mud, it is easier to work with. Spackling paste is more difficult to use, save it for small repairs. Apply 2 thin coats then sand. Use a medium/fine sanding sponge, it works a little better than sand paper.
After the repairs are finished and dry, prime the raw drywall mud then paint as usual.