# Question about green mold on plywood.



## eddit (Oct 8, 2018)

Most of the mold-related post here were about drying lumber so I wanted to ask a new question about my issue.

I use 1/2 walnut or maple veneered plywood for back panels on furniture projects. I had some extra from my last project so I tossed it in the shed in the summer.

Pulled it out today and noticed spotty green mold growth similar to this photo:










I was able to wipe it off easily with a few moist paper towel, and I gave the whole board a light sanding.

My question: am I good to go, or should I take a further step of wiping the board down with denatured alcohol or mineral spirits?

Needless to say I won't be storing lumber in my shed over the summer anymore.


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## Rick Dennington (Aug 27, 2009)

I've had this happen to me a few years ago. To answer your question, take a 1/3 cup of bleach or less and a gallon of water…...mix throughly, and wipe the plywood down, saturating it all over. You should see the mold starting to disappear…...!! Let the mixture set for a few minutes, then wipe it down…again, and let it dry. That should do it.


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## Axis39 (Jul 3, 2019)

I have been told that household bleach is not strong enough to kill mold spores. I would never water it down and expect it to work as a long term solution. I am not a mold specialist, but that was advice I have been given in the past.

There are several products available in any hardware type store. I've used Mold Armor a good bit and found it to work quite well.


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## eddit (Oct 8, 2018)

Thanks fellas. I've decided to use the piece for shop jigs instead, and to just buy a new piece for the current furniture project. Either way I'll do a heavy wipe-down of denatured alcohol (no water) to kill any lingering mold spores. Thanks for taking the time to chime in.


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## Lazyman (Aug 8, 2014)

Heat is the best way to kill it but it might need to get too high and for too long for the plywood. Fungus mycelium can grow deep enough into the wood to avoid any surface treatments so you may have to heat it long enough to raise the internal temperature to the lethal point. I am not sure how well the plywood will handle that.

BTW, that probably indicates that the moisture content got pretty high so you might want to check that if you have a meter. You also might need to reconsider storing wood in that shed if the MC is high enough for fungus to grow.


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## eddit (Oct 8, 2018)

Yep I agree. Its dark, with limited air circulation. Definitely not doing that again.


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## Unknowncraftsman (Jun 23, 2013)

Is it weird that I think the green mold with the tan and yellow background is pretty.


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## MrUnix (May 18, 2012)

> Is it weird that I think the green mold with the tan and yellow background is pretty.
> - Aj2


To me, it looks like some aerial photography of a flowing open field with a few trees scattered around 
Kind of reminds me of Iowa!










Cheers,
Brad


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## Unknowncraftsman (Jun 23, 2013)

Nature's art.


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## ColoradoJake (May 14, 2019)

I used to be in mold remediation and I know first hand that bleach will not kill mold. All bleach does is literally bleach the mold, make it clear. I am unsure on denatured alcohol. Many of the mold killing products we used were natural and the main active ingredient was Thyme.

Take this for what you want, but please stay safe.


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## Unknowncraftsman (Jun 23, 2013)

> I used to be in mold remediation and I know first hand that bleach will not kill mold. All bleach does is literally bleach the mold, make it clear. I am unsure on denatured alcohol. Many of the mold killing products we used were natural and the main active ingredient was Thyme.
> 
> Take this for what you want, but please stay safe.
> 
> - ColoradoJake


In my roofing days we sometimes see black mold in areas that had a long time leak. So long that ants seemed to like the rotting timbers. Or the mold


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## Vintagewood1960 (Jan 14, 2017)

I had a similar issue and researched white vinegar as the best solution. I used it before painting my already ruined cherry veneered plywood. It was ruined by bad advice to use bleach.


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## SallySawzIt (Sep 24, 2021)

If you search for "Boric Acid for mold on wood" it will result in the way to use the boric acid to clean up mold on wood. There is also a product called Bora-Care you can use prior to storing your wood that not only prevents mold but termites, wood borers or other insects. Bora-Care isn't what I would consider cheap but it can save a lot of wood.

I can't tell how overall effective it is, but I've sprinkled Boric acid on wood prior to storing.


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## controlfreak (Jun 29, 2019)

Above is correct, bleach will bleach mold but not kill it. You need something like this.


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## tvrgeek (Nov 19, 2013)

Good information. I have always heard not to use bleach, but never why.


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## squazo (Nov 23, 2013)

certain molds are killed by bleach, some are not affected by it. Same with vinegar, so I usually just both. I guess this is where I should tell you mixing bleach and vinegar makes some sort of toxic gas and you probably should do it in separate applications. I on the other hand just mix it together anyways, and only use it outside. I use it as a siding cleaner. Lots of antifungal cleaning agents are available at most stores, Lysol for instance.


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