# Zinsser Mold Killing Primer on Wood



## sbkim (Apr 30, 2012)

Hello,

Zinsser states that their mold killing primer is only for non porous surfaces. I am curious if I can use this on plywood/2x4 surface that has mold? 

Or do I need to seal the wood first and then use the mold killing primer? I am a little confused because I see this being used on drywall which I thought is porous...

Thanks


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## Nestor_Kelebay (Jun 17, 2008)

Hmmm. A primer than can't be used on porous surfaces like bare wood, drywall and joint compound. Sounds like a lawn mower that's not to be used outdoors.

Does Zinsser have a 1-800 Customer Service phone number anywhere on that can?

If I were you, I'd leave that Mold Killing Primer on the shelf in the store and clean your wood with bleach diluted with 5 parts water. Then rinse the wood down with clean water, allow time to dry and use a NORMAL primer on that wood. That is, a primer that's meant for surfaces that need to be primed.


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## sbkim (Apr 30, 2012)

Thanks. I will plan to use their Bulls Eye 123 primer that seems to be OK for porous surfaces like wood. I presume having primer that is resistant to mold is not a bad idea after cleaning the mold?

http://www.rustoleum.com/product-ca...mer-sealers/bulls-eye-1-2-3-water-base-primer



Nestor_Kelebay said:


> Hmmm. A primer than can't be used on porous surfaces like bare wood, drywall and joint compound. Sounds like a lawn mower that's not to be used outdoors.
> 
> Does Zinsser have a 1-800 Customer Service phone number anywhere on that can?
> 
> If I were you, I'd leave that Mold Killing Primer on the shelf in the store and clean your wood with bleach diluted with 5 parts water. Then rinse the wood down with clean water, allow time to dry and use a NORMAL primer on that wood. That is, a primer that's meant for surfaces that need to be primed.


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## LeakyHawaiiRoof (Oct 21, 2014)

If you can't use bleach-water or if you want to kill off every last mold spore possible, you may want to consider also spraying the wood with Concrobium mold control before applying the primer. Concrobium crushes the mold root to kill it.


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## sbkim (Apr 30, 2012)

Yep, used Concrobium to kill what's there. I had done this last year but it seems like they came back even with only 65% humidity and under 60F temp. I will clean up the area use primer/sealant.


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## Nestor_Kelebay (Jun 17, 2008)

sbkim said:


> Thanks. I will plan to use their Bulls Eye 123 primer that seems to be OK for porous surfaces like wood. I presume having primer that is resistant to mold is not a bad idea after cleaning the mold?


Actually, when it comes to adhesion to wood, the best primers were the old linseed oil based primers that no one makes or sells anymore because they took 3 or 4 days to dry to the touch. That's because linseed oil molecules were small enough to penetrate deep into the wood cell walls and wood cell interiors.

Second best would be an ordinary alkyd primer (which you can still buy). The problem with these is that you have to clean off your brush with mineral spirits and wait while the stuff gravity separates or chuck the brush, both of which are an annoyance. The reason alkyd primers have better adhesion to wood than latex primers is because of the size of alkyd primer resins. They're very much smaller than latex resins, and that allows some degree of penetration of the alkyd resins into the larger wood cells. 

Latex primer resins are way too big to penetrate into wood cells. They just sit on the surface of the wood, so you're relying entirely on the adhesion of the primer resin to the wood rather than chemical crosslinking between the stuff that penetrated into the wood and the stuff still on the outside of the wood like you have with linseed oil based primers and to a lesser extent alkyd primers.


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## sbkim (Apr 30, 2012)

Thanks. This is a cellar with no ventilation and as such would liklike to use low odor and voc if possible.


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## LeakyHawaiiRoof (Oct 21, 2014)

sbkim said:


> Thanks. This is a cellar with no ventilation and as such would liklike to use low odor and voc if possible.


perhaps a dehumidifier will also help prevent mold growth after painting. There are some dehumidifiers that can automatically turn on when humidity gets about 50% or some other level.


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## sbkim (Apr 30, 2012)

Yes, I have dehumidifer in the room but didn't turn it on as the room was dipping in the low 40s during winter. 

so what I am gathering from our discussion is that killing mold, dry, and sealing is the way to go. I just thought that zinssee mold killing paint would have done this in one shot.

Below is link to the product. 

http://www.rustoleum.com/product-catalog/consumer-brands/zinsser/primer-sealers/mold-killing-primer


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## ToolSeeker (Sep 19, 2012)

It really doesn't matter what you use If you don't address the moisture issue and get some air moving it will return.


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