dry wall prep before painting

[87GN]

I've replaced the dry wall on one wall and the other walls have 3 layers of wallpaper. I've removed the wallpaper using a wall paper steamer. Do I use a sealer (something like Gardz problem surface sealer) before fixing the gouges/scratches/etc with joint compound or after? Seal the new drywall also? Then primer, then paint? Thanks.
Mark

 

[NUTTSGT]

I would prime after you have all the prep work done.

 

[LWB]

Do your repairs, prime then paint.

 

[Bucko]

As others have said above but I will add that you should look for a wall paper adhesive removal solution. I made the mistake many years ago of not removing all the old adhesive and the paint later started to flake but the flakes had the glue attached to it as well. I figured the paint softened the glue and it lost its bond to the surface over time.

 

[Rusty Wrench]

As others have said above but I will add that you should look for a wall paper adhesive removal solution. I made the mistake many years ago of not removing all the old adhesive and the paint later started to flake but the flakes had the glue attached to it as well. I figured the paint softened the glue and it lost its bond to the surface over time.

Especially this!
Wash twice. Bits of leftover schmutz are hard to see. Until it's painted. Then you see all of it.

 

[The Cobbler]

actually, I'm going to go against the posters here. I've done tons of this type of repairs . it wouldn't hurt at all to prime first, then a light sand over everything and then patch .

 

[jskicet]

Complete repair, sand. I also would lite sand any new sheet rock at that moment then Prime and lite sand again. Paint

 

[87GN]

Thanks everyone for the suggestions.
Mark

 

[pcmeiners]

Thoroughly clean off the wall paper paste remains first. Apply a thinned coat of primer oil or shellac, do repair , sand, remove dust, apply a thinned coat of primer, oil or shellac. Go over the entire area with a sanding block to knock of bits of **** on the surface, go fast, you can do an average sized room in 20 minutes or less. Apply top coat. Do not use latex primer, it ***** as far as adhesion except over latex flat or eggshell. Paint with primer is ********.

 

[Stelzer]

It's one of the only times I have my painters prime/seal twice. Once before repairs, once after. The problem with not sealing the surface before repairs is the residue from wallpaper paste, (glue), can cause adhesion issues with mud, can cause bubbles to form in the mud, and the mud can also re-wet the paste, making a hell of a mess. Gardz locks it down. No pesky wallpaper bits stuck in your skim coat either.
Seal, repair, re-seal, paint, live happily ever after.

Not sealing before repairs is a gamble.
It could work in your favor and could save you an hour by not sealing before repairs
Or, it could bite you in the **** and have you chasing your tail for the next several hours to get back to where you started.

 

[Fav Onefour]

I've dealt with wallpaper gunk and a few variables.

@87GN, Did the walls have a good paint coat under all that wallpaper? I'm also curious what type of adhesive was used. Answers to either of those two questions can affect the advice.

Scoring the paper generally means the walls should be sanded, patched, and sanded at the very least. Some of the peel and stick glues leave a lot of residue that make sanding near impossible. If there is good paint under the paper, it will help to soak and remove the residue before repairs. If the wallpaper was installed right over primer coat, things get tougher. I won't say impossible, but I've seen some that were close. The scored surface allows soaking to get into sheetrock paper. Adhesives bind to primer coats bind so well that it takes a lot of soaking to get the residue, bla, bla, bla. I think you get the point.

Some of those old school glues are pretty easy to remove. If that is the case, the residue may come off primer coat just by using a warm water solution. If you have old school glue on good finish paint, try using a wet sponge and a 4" joint blade to scrape. Those glues have less tendency to bleed through paint. A little residue won't be a deal breaker. You might get by with a good sanding.

A little residue can make a big mess. Often, it bleeds through or doesn't allow next layer to stick. If you're not sure, try patching or painting a test area and wait for it to dry.
It's a pain to do all those steps just so you can recoat. It's more of a pain if you have to do them over after you recoat.

One tool I've added for these projects is a basic drywall power sander. I have a lot of hours on my cheapo HF version. I must be around a hundred sheets on the thing and it's still going. Life is a lot simpler with that tool. It still amazes me that I waited so long to get one. I've done a lot of sanding and finishing over the years and tried all sorts of tricks. Those sanders make a big difference with messy big wall remodel projects. I do an initial sand and inspection before I even think about patching. Side lighting off the head also highlights any imperfections.

 

[The Cobbler]

I'll expand on my previous post .
While I didn't always prime before patching, priming does show a lot of imperfections that don't show up without the primer, it seals the surface and I find it does a smoother job faster than not priming. it can slow down the drying as the water in the compound has to evaporate off the surface & not sink in.
either priming or not will give basically the same results , there's no right or wrong way in my opinion.
as far as the wallpaper glue, yes, that can be an issue , get as much off as you reasonably can . I used to wash the walls with terry cloth rags, swipe with a wide knife downwards towards the floor and wipe the area with clear water . sometimes I probably did that 3 times if the glue was heavy . also sand it when dry with a drywall power sander . I wish I had more pictures of my many jobs in repairing rental units , then again, maybe it's better that I don't LOL