# drywall



## chilangopolaco (Apr 22, 2008)

I was trying to replace an old fugly wall-paper with nice new paint. I peeled off wallpaper and this is where problems started….Under the wallpaper it was another leyer of paper …I started peeling it off (water + soap) and it caught some of the drywall. Now my drawall has 3 dimensions .. old compound, drywall and one leyer underneath the drywall (I did not go as far as gypsum)…To remedy the problem I was thinking to apply compound all over ..sand it once it dries and then apply some good paint that containts primer and sealer…what do you think ? thanks


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## kgphoto (Dec 2, 2007)

Use a primer to seal it first or you will get bubbling. A specific primer for that use is Gardz.


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## slickshift (Aug 25, 2005)

A coat of Zinsser's Gardz
Then your drywall patching (joint compound)
Sand smooth and clean free of dust
Then a quality primer
(you can use the Gardz if you still have some, but a regular Zinsser, Ben Moore, or Sherwin Williams, primer would be great also)
Then a quality paint for top coating


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## chilangopolaco (Apr 22, 2008)

thanks a lot, question though
Zinsser's Gardz (Gardz high performance sealer) is primer/sealer…do I still need to apply compound over the sealer ? On the label it says “repairs torn paper and damage drywall”…I was thinking to cover my drywall with it then just paint it with some bathroom oil based paint ?


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## slickshift (Aug 25, 2005)

From your description I assumed you would need some joint compound repair
The Gardz will make the fuzzy drywall hard enough to repair/paint, and seal in adhesive residue, and penetrate some leftover wall coverings to seal them, but it won't fill in any level changes from old/older/ripped spots

You can use an acrylic paint over whichever primer you use, oil or Gardz


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## Sir MixAlot (Apr 4, 2008)

chilangopolaco said:


> thanks a lot, question though
> Zinsser's Gardz (Gardz high performance sealer) is primer/sealer…do I still need to apply compound over the sealer ? On the label it says “repairs torn paper and damage drywall”…I was thinking to cover my drywall with it then just paint it with some bathroom oil based paint ?


:yes: Sounds like you still need to skim those areas after the gardz.:thumbsup:


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## Nestor_Kelebay (Jun 17, 2008)

Chilangopoloco:

If I was you, I'd restore the strength of the drywall anywhere you've remove perhaps too much surface paper. Just put strips of fiberglass drywall joint tape vertically across those areas, paint with diluted white wood glue, then horizontally, and paint with diluted white wood glue. AS the glue dries, it'll bond the fiberglass mesh to the surface of the wall and replace the strength that was provided by any paper that is now missing.

Then skim coat the wall with drywall joint compound, BUT, maybe use a "Taping" or "Regular" joint compound instead of an all purpose or a finish. Taping joint compound has more glue in it so that it sticks better and dries harder. YOU CAN use an all purpose or finish (also called "topping") compound, but it would likely dry too soft and your walls would dent and get superficially damaged very easily.

There are two easy ways to skim coat, and you'll have to decide which works best for you:

1. use a "V" notch adhesive trowel to spread your joint compound onto the wall, mist with water and then flatten it with a normal plastering trowel. Work small areas at a time.

2. use a "V" notch adhesive trowel to spread your joint compound onto the wall, allow to dry. Then, after knocking off anything that's sticking out, hold the trowel upside down and fill in the ridges with more joint compound.

But, regardless of which method you choose ALWAYS ALWAYS ALWAYS, whenever spreading joint compound or sanding it smooth, work with a bright light positioned close to the surface you're working on. This will cast light on your work at a sharp angle, exagerating the roughness and giving you an eye for where you have to spread or sand to get the surface smooth. Once it looks "not as ugly as i feared", it'll look OK under normal lighting. And, as you acquire experience and skill, it'll look OK under critical lighting and perfect under normal lighting.

And finally, walls and ceilings don't need to be flat any more than magicians have to do miracles. As long as a wall or ceiling is SMOOTH, the eyes will tell the brain it's also flat because walls and ceilings are presumed to be flat, and a smooth wall or ceiling won't show any evidence to the contrary. Just hold a bright light beside any wall or ceiling in your house and you'll find out that none of them are very flat, but they're all fairly smooth, thereby fooling you into presuming they're also flat.

Personally, I never use boxed joint compounds. I prefer to buy powdered compound in bags and my white wood glue in a plastic gallon. That way I can mix the compound as soft and easy to sand as I like, or as sticky and hard drying (and hard to sand) as I want as well. I tried a premix one time, and I believed you needed to have the wrists and arms of a silverback gorilla to spread that stuff. DO NOT hesistate to thin your mud with some water to allow it to spread smoother. Transportation costs money and no one wants to be buying water transported at high cost from another city. So, they mix the premix as thick as they can because they know that people can always thin it themselves. Don't be scared to do that.

After you get your joint compound smooth, then I'd prime with any PVA primer and top coat with any top quality latex paint. You don't need to use any special primer. If you're wanting to prime over a vinyl coated wallpaper, I'd probably go with Zinsser's Bullseye 123 cuz Zinsser's brags about how it'll stick to anything.

But, if your wall looks "rough" you'd do well to skim coat and sand smooth, and then just use normal primer and paint to complete the wall.


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## Nestor_Kelebay (Jun 17, 2008)

You said: "sand it once it dries and then apply some good paint that containts primer and sealer"

Paints don't contain "primer and sealer".

Primers and flat paints contain huge rocks that are almost large enough to see with the naked eye called "extender pigments". It is the addition of these extender pigments (that are typically made of chaulk, talc or pulverized silica sand) that cause the white liquid to be a "primer and sealer".

What happens is that these huge rocks get drawn to the surface of the drywall or joint compound as the primer is absorbed into it, and the rocks plug the porous surface of the substrate (thereby sealing the substrate). As the liquid (latex or oil based) dries, it's thickness shrinks and these huge rocks start to stick out of the drying film thickness making it rough. It is those huge rocks inside the paint or primer film that result in them drying to a matte finish that a subsequent coat of paint will stick well to. So, it's them same dumb rocks that make a primer also a sealer.

Thus, a paint that contains primer and sealer would be any flat paint.


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