Alright, i picked up the job a family friend. They had already had one person start removing wallpaper , they did a terrible job and damaged the drywall in many places. Large areas got scraped down to the brown cardboard like layer. The end goal is to spackle the walls to refinish them.

To what extent is it necessary to sand the walls before applying sealer primer to the walls? Should i not sand it at all?

 

Remove all the glue you can and any loose paper. If there's any exposed gypsum, prime that with Zinsser Gardz (oil based primer is ok if you can't find Gardz), then skim coat with joint compound (not the spackle you mentioned), prime and paint with quality primer and paint purchased at a paint store, not a paint department.

 

If you can post pictures that would be helpful.

 

Ive. Sanded some of the walls down already , i just dont want to be wasting my time and energy doing unnecessary work.

 

Sanding doesn't hurt but I wouldn't go overboard. Once you've scraped off what you can, prime the entire wall with Gardz. That will seal both any leftover adhesive along with the bare gypsum. Then you can skim coat as needed, sand, prime with most any latex primer and paint.

 

Would this be an acceptable substitute for Gardz

 

No!! It must be Gardz [water based] or an oil base primer. All other latex primers can cause issues with both the adhesive and the exposed gypsum, especially near torn paper. Plus Kilz2 is generally thought of as a poor quality primer.

 

Kilz premium isn't as bad as kilz2. But mark is right, you don't want to use a latex primer. Either use Gardz or any oil primer. That will seal the brown paper so that you can lightly sand, then you will have to skim everything that you want to be perfectly flat and smooth with joint compound. Then sand, skim again, sand again, etc.

Skimming is a lot of work... it's often best to roll the wall using a heavy nap roller on a paint pole with thinned joint compound, let it start to tack up a little, then use a wide knife to smooth it out. Your 2nd skim coat can usually be with just a pan and knife. If you're good a 3rd skim won't be required. Then the wall will need primed (latex primer) and lightly sanded, and if no defects show (shine a bright light on the wall) then you're ready for paint.

 

Awesome , sounds like a plan then. Many thank you's to those that responded. I really appreciate it .

 

On the home depot website Im seeing Gardz listed at $48 a quart? I dont feel like thats correct. Because that is insane $90+ a gallon

 

I think if you read the fine print it probably says that's for a case of 6, and it's not available at your local store. Its giving you prices for shipping items not available in store. Menards or Sherwin Williams stores should have Gardz in stock.

 

FWIW, $48/quart would equate to $192/gallon and you're right, that would be insane.

 

The damage is pretty extensive. Gardz only and see if it holds. Those areas where the paper is completely missing will have to be replaced with new drywall. Gypsum without a paper face crumbles with any pressure put on it.