# Zinsser Gardz over skim coat over wallpaper adhesive?



## boilerturf (Feb 1, 2015)

I have a recently purchased house that we are doing a complete remodel to. As my wife and I tore out some drywall on exterior walls we found mold on the insulation. She insisted that we rid the house of mold by getting new insulation and new drywall on those exterior walls.

In our main bathroom we used a wallpaper steamer to remove the wallpaper on all walls. The interior walls remained in place but the one exterior wall was replaced with new drywall. Before we were able to remove all the wallpaper adhesive from the interior bathroom walls our drywall contractor advised us that his crew could just skim coat over the adhesive and it would be fine to paint over.

Now that their crew is gone my wife and I have seen areas where skim coat didn't cover the wallpaper adhesive. This visible area of wallpaper adhesive is located directly where paint will be noticeable between the vanity and the mirror.

While it would have been best to have scrubbed off the wallpaper adhesive with a sponge and warm water prior to the skim coat, that isn't much of an option now. 

What is the best way to make this a paintable surface without activating the wallpaper adhesive which would cause bubbling and peeling of the paint?

- Can I use Zinsser Gardz to seal the adhesive and joint compound? 

- Since this is a bathroom, should I apply two coats of Gardz in order to make sure moisture doesn't get through to that adhesive?

- After the coat of Gardz do I need to scuff it up or sand it?

- Should I prime with a premium primer after the Gardz (I was recommended Benjamin Moore Fresh Start Multi-purpose Latex for it's mildew resistance)?

- Do I need to sand the primer before painting?

After the wall is sealed and primed I will be painting with Benjamin Moore's Aura Bath and Spa. I already have a gallon of each of these products in my possession. Do I need something different?

Thanks in advance.


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## Jmayspaint (May 4, 2013)

The Guardz may work to seal in the residual paste. However, if the left over paste is heavily concentrated it may not work. I've had mostly good luck with Guardz but in a couple instances where the residual paste was extra heavy, it failed to completely seal it in. This resulted in isolated "curdling" of the finish coat. 
If the paste on the walls cannot be removed I might try two coats of Gardz. No real need to prime over that before painting and its not necessary to sand the Gardz though you may want to in order to create a smoother profile on the wall. 

Here is a picture of what I mean by "curdling". This has happened on a wallpaper removal job where the residual paste was not adequately removed prior to applying Guardz. This effect was not visible in the Guardz coat, but only became apparent in the finish coat. Sanding down the affected area and reapplying Guardz fixed the problem. 

Aura Bath&Spa is a fine product and should perform as well as anything.


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## boilerturf (Feb 1, 2015)

If I primed after the Gardz with the white Fresh Start would that show "curdling" before applying the finish coat? Does the white primer have enough pigment to cause the "curdling" so I could see it since the Gardz is clear and hard to detect "curdling" imperfections?


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## Jmayspaint (May 4, 2013)

boilerturf said:


> If I primed after the Gardz with the white Fresh Start would that show "curdling" before applying the finish coat? Does the white primer have enough pigment to cause the "curdling" so I could see it since the Gardz is clear and hard to detect "curdling" imperfections?


I would think so.


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## boilerturf (Feb 1, 2015)

Another couple questions regarding Gardz. I've read that it is difficult to apply because it is so thin. Should I use a microfiber roller cover to apply it?

Also, if I have left over Gardz should I roll it over joint compound on the drywall joints in the sunniest rooms of the house to seal those spots from flashing? For the bare drywall in the rest of the house I plan on priming with PPG Speedhide 6-2. Isn't 6-2 a PVA primer? How will that adhere over the joint compound spots I seal with Gardz?

Thanks!


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## chrisn (Dec 23, 2007)

boilerturf said:


> Another couple questions regarding Gardz. I've read that it is difficult to apply because it is so thin. Should I use a microfiber roller cover to apply it?
> 
> Also, if I have left over Gardz should I roll it over joint compound on the drywall joints in the sunniest rooms of the house to seal those spots from flashing? For the bare drywall in the rest of the house I plan on priming with PPG Speedhide 6-2. Isn't 6-2 a PVA primer? How will that adhere over the joint compound spots I seal with Gardz?
> 
> Thanks!


yes and since you will already have the Gardz, just use it to prime all the drywall, it will work better(IMO) than the speedhide


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## boilerturf (Feb 1, 2015)

chrisn,

I have only a 1 gallon can of Gardz specifically for sealing the wallpaper adhesive in this bathroom. I had purchased a 5 gallon pail of the Speedhide 6-2 from a local paint store to support his small business and his superior expertise over the SW guy fresh out of college. That 6-2 was to be used on all of the other rooms in the house.

Should I return the unopened 6-2 and buy more Gardz for everything else?


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## jeffnc (Apr 1, 2011)

I would also try to get off any obvious remaining wallpaper paste where you find it, then put on 1 coat of Gardz over everything, and no additional primer. It is thin, but just go over it a couple times to ensure there are no ridges and runs and you're fine. The roller cover isn't too important as long as it's non-shedding and has a beveled edge, but a microfiber would be fine of course.

I would also use Gardz on any additional drywall since it's a very good sealer, with none other needed. Gardz is marketed as a "problem drywall" solution, but in fact it's also a good plain drywall sealer. They really ought to market it this way. You will notice that paint takes longer to dry over Gardz than over bare drywall, and also over probably any other drywall primer you've used. This shows you just how well it seals the drywall - water from the paint isn't soaking into the wall at all really, and so it appears wet longer.

See also
https://jackpauhl.wordpress.com/category/bare-drywall/
http://www.jackpauhl.com/introducing-gardz-by-zinsser/


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## Jmayspaint (May 4, 2013)

One thing about Gardz is I wouldn't try to spot prime with it. It seals so well that isolated spots done with it in the middle of a wall can show a sheen difference through the top coat from the surrounding area. Better to do the whole wall or use a regular drywall primer for isolated patches.


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## boilerturf (Feb 1, 2015)

jmayspaint,

I saw on Jack Pauhl's website that jeffnc linked to that just spot treating with Gardz produced a different shine compared to adjacent primed walls. Because of this and your advice I will go ahead and use Gardz on the entire wall.

I am able to return my unopened 5 gallon pail of Speedhide 6-2 and the price per gallon of Gardz is comparable to the 6-2.

Thanks for all of your advice!


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