# Will Oxyclean kill mildew for exterior painting?



## Homerepairguy (Aug 1, 2010)

Will Oxyclean work to kill mildew on the exterior of homes prior to painting?

I've seen recommendations to use 1 bleach to 3 water to kill mildew but I'd prefer to use Oxyclean if it will do the same job. It Oxyclean has worked for you, what ratio of Oxyclean to water did you use?

Here's an example of the Oxyclean I would buy if it can work. Is it the right one?


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## Jmayspaint (May 4, 2013)

I doubt it. I've never seen a non-bleach based wash that would, really. And I've tried several. 

1/4 bleach water is strong. You shouldn't need it that strong unless your trying to kill moss on your roof or some seriously heavy mildew. I normally wash with 1/10 bleach water and a little soap. That's strong enough for normal house washing.


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## noquacks (Jun 5, 2010)

Right- 1:3 or 1;4 is way strong- overkill (pun??). temndency is for people to use bleach way strong, including inside cleaning chores like toilets, etc. Bleach is a very powerful oxidizer. Dilute it like 1;10 like Jmay said.


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## Will22 (Feb 1, 2011)

A mild bleach solution should be sufficient.


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## Homerepairguy (Aug 1, 2010)

Jmayspaint, noquacks and Will22,

Thanks for helping out. I was reading the instructions on the Oxyclean box in the store and it lists things NOT to use it on. Latex paint was one of the no-no items. So cleaning the house with Oxyclean is definitely out since our house was last painted with latex many years ago.

I'll clean our house in preperation for painting using the 1:10 proportion suggested by Jmaspaint.

Should I scrape all loose paint before applying the bleach solution?

Should I strip all areas that have peeling paint using a chemical stripper to remove spotty areas that are difficult to scrape off? We have a ranch style roof. Basically on the gable end side of the house facing east (weather), the lower 2/3 of the paint is peeling. On the side of the house that has 8' walls facing north, the lower 1/3 of the paint is peeling.

Would the following procedure be correct?
1. Scrape off all loose paint. (use chemical stripper?)
2. Spray the bleach solution on about a 10 foot wide area of the eaves and wall) using a garden pump sprayer.
3. Wait 10 minutes.
4. Re-wet the area using a pistol grip nozzle on a garden hose.
5. Scrub with a brush on a pole.
6. Rinse the area using the pistol grip nozzle on a garden hose.
7. Let dry for about 2 days.
8. Sand the transitions from paint to bare wood to feather the paint.
9. Apply oil primer to the bare wood areas.
10. Pole sand the entire wall including old paint and new primer.
11. Apply latex primer over old paint and new oil primer.
12. Apply 2 coats of acrylic latex paint. (3 coats on the weather side of the house)

Thanks,
Skyglider


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## housepaintingny (Jul 25, 2009)

Only sodium hypochlorite (active ingredient in bleach) will kill mildew. Other cleaners may remove it temporary, but will not kill it. In general for preparing a home for painting or staining the mix is 1 part bleach and 3 parts water, but that depends on the strength of the bleach too.


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## Canarywood1 (May 5, 2012)

Go to HD and get a gallon of Mold Armor, recommended for mold and mildew removal before painting, and it works where keeper plants are located, READ THE DIRECTIONS before using.


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## Jmayspaint (May 4, 2013)

Homerepairguy said:


> Jmayspaint, noquacks and Will22,
> 
> Thanks for helping out. I was reading the instructions on the Oxyclean box in the store and it lists things NOT to use it on. Latex paint was one of the no-no items. So cleaning the house with Oxyclean is definitely out since our house was last painted with latex many years ago.
> 
> ...



That sounds pretty good. Probably the only thing I would change would be the order of the washing. 

I like to wash first. Primarily because if your scraping the side of a peeling house and you scrape off all the loose stuff, then wet the surface and let it dry, some paint that was stable before will become loose. 

I other words, the wet dry cycle causes the edges of previously sound paint (what would not scrape off) to lift, and more scraping will be needed. That's not necessarily a bad thing, and washing after scraping will work fine. Its just that you'll probably need to scrape some again after the wood dries. 

I do; wash, scrape, sand, prime, paint. My preferred way to remove sanding dust is to use dustless sanders and vacuum after, or just blow the surface off with a electric leaf blower. IMO its much easier to remove dust dry, rather than wet. 

A tip for washing with weaker bleach solutions is to really wet the surface with the mixture. Don't just most it, really wet it down and let it dwell a few minutes. Adding just a little laundry soap or dish soap that can be mixed with bleach helps the bleach cling to the surface and work better. Also a bit of suds lets you see why your doing better.

Edit; if your considering using chemical strippers, that's going to change things. You would not want to follow a chemical stripper with a bleach wash. Most strippers require a follow up wash with a neutralizing acid wash. Using bleach would be dangerous.


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## Homerepairguy (Aug 1, 2010)

housepaintingny said:


> Only sodium hypochlorite (active ingredient in bleach) will kill mildew. Other cleaners may remove it temporary, but will not kill it. In general for preparing a home for painting or staining the mix is 1 part bleach and 3 parts water, but that depends on the strength of the bleach too.


Hmmm, suggestions so far for the bleach:water mix are 1:3 and 1:10.

I just did some Googling and found:
... Benjamin Moore website suggests 1:5.
... Sherwin Williams website suggests 1:3

I'm thinking about going with the 1:5 mix using 1-bleach, 1-SimpleGreen, 4-water.

Thanks,
Homerepairguy


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## Homerepairguy (Aug 1, 2010)

Canarywood1 said:


> Go to HD and get a gallon of Mold Armor, recommended for mold and mildew removal before painting, and it works where keeper plants are located, READ THE DIRECTIONS before using.


I researched Mold Armor. Apparently it's a mix of sodium hypochlorite (bleach), soap and water. One poster on amazon said it contains 5% sodium hypochlorite. I just checked our gallon of Clorox and it says it contains 8.25% sodium hypochlorite.

Good thought though. Thanks,
Homerepairguy


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## Homerepairguy (Aug 1, 2010)

Jmayspaint said:


> That sounds pretty good. Probably the only thing I would change would be the order of the washing.
> 
> I like to wash first. Primarily because if your scraping the side of a peeling house and you scrape off all the loose stuff, then wet the surface and let it dry, some paint that was stable before will become loose.
> 
> ...


That's really helpful info. I'll add soap to my bleach mix. And I'll bleach wash first, before doing any chemical stripping and neutralizing.

My revised procedure will be:
1. Clean with bleach mix.
2. Scrape loose paint.
3. Apply chemical stripper to scraped areas as necessary to get down to all bare wood.
4. Scrape chemically loosened paint.
5. Apply stripper neutralizer.
6. Sand the transitions from paint to bare wood to feather the paint.
7. Apply penetrating oil primer to the bare wood areas.
8. Pole sand the entire wall including old paint and new primer.
9. Apply latex primer on entire wall, over old paint and new oil primer.
10. Apply 2 coats of acrylic latex paint. (3 coats on the weather side of the house)

Thanks,
Homerepairguy


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## Homerepairguy (Aug 1, 2010)

*Decided not to use a chemical stripper*

DON'T RESPOND TO THIS POST. I DECIDED TO OPEN A NEW THREAD WITH THE PROPER SUBJECT.

After more research, I decided not to use a chemical stripper because of the following reasons:

1. I saw a youtube video where the guy said to avoid getting chemical strippers in cracks and crevices, since residue not removed could affect subsequent primer and paint. Our house walls are T&G so there are vertical v-joints every 7 inches. Sounds like it could be a big problem using a chemical stripper.

2. I wasn't able to find a chemical stripper locally that had a neutralizer. Some said to remove residue using paint thinner. Another said to remove residue using TSP. Heck, I want to "neutralize" the stripper, not depend on removing all traces of it.

3. I read one post that mentioned the possibility that a chemical stripper could be absorbed into the wood preventing good bond of primer applied. Not sure if this is valid but it sure raised my eyebrows.

So I'm going to try to build an infrared paint remover if I can find the parts. Anyone here build one?

HRG


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