Oxalic Acid on all wood or just in treated

Hey guys so I’m new to wood cleaning and I have a few questions. I know when cleaning a wood fence or deck if it’s untreated you want to do the following steps. Wet the wood really well, apply sh and let it dwell, rinse off and than apply oxalic acid, let it dwell, and than rinse again. What about treated or a stained deck or fence, that just happens to be dirty? Or better yet if your doing a House wash and the house has wood siding that is painted but just dirty. Do you just just apply mix and rinse? Or do you need to apply oxalic acid after?

@Chris any update on fixing the search bar? @Infinity maybe we can pin the post you made with the link to the search bar until it gets fixed

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I need that link back too. Need to find Williams cat picture for the other thread :joy::joy:.
@B16bri no need for oxalic on the painted wood but dont use a very strong SH mix on it.

As far as the other woods just dont use more than a 2% sh. Most wood doesn’t need more than 1% sh then follow with enough pressure to take off any film and rinse really well.

The popular wood cleaning technique you are referring to is hitting it with sodium percarbonate then rinse then oxalic and rinsing again.

Epee can be pretty though stuff and you may need to use lye on it sometimes. It all depends on what you are cleaning.

If you have a job coming post some pics and provide as much info as you can. Some people here will help you out.

It depends on the type of the wood, what is currently on the wood, and what organic growth the wood has on it. Painted wood (especially if its thin) can bleed out quick during a wash. If your cleaning a fence hit it with sh, or oxalic acid. Most people don’t do both as fences aren’t traditionally stained or painted as often. If you are staining or painting it then yes you would want to neutralize the wood before any such application.

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If never neutralized it before staining it but i also usaully wait a few weeks before i come back to do it anyways.

Got a restaurant with a wood deck patio. It was originally painted but most of that paint is gone. If you have even done restaurants, you know the oils and grease from the kitchen just work their way everywhere. Currently the deck has a layer of this oil/grease/dirt as well as some mold and algae.

Was thinking of hitting it with EBC, light scrubbing then rinse to get as much of the grime off. Come back with SH for any of the mold/algae still on it. Rinse. Not going to worry about OX as I feel it is going to take several cleanings to get all the grime out of the wood. Anyone tackle this version of deck cleaning in a restaurant?

Normally would never use hot or warm water on wood, but in this environment would you?

I personally haven’t but I do know @MDA1775 uses potassium hydroxide for grease stains on decks. He should be able to help.

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I have had good success with using potassium hydroxide to get grill grease out of older decks. I usually clean them with sodium percarbonate as the general cleaner and then hit the individual spots with the potassium H, followed by oxalic to adjust the PH back to neutral. I use DSR-50, it’s a liquid. I start with a cup per gal and increase as needed. Standard practices, don’t let it dry and I use a short stiff bristled brush (Quikie Brush $7.98 with pole at HD or Lowe’s) to scrub it in. Repeat as needed. If it starts furring too badly I’ll tell the customer were we are and ask what would they like to do, replace boards, heavy sanding etc. They are generally good with it as is since it looks so much better. I am also usually applying a heavily pigmented semi-transparent stain from Wood Defender and it hides a lot of imperfections.


I bought a 50lb bag of raw sodium percarbonate and have a job where the customer has a country style mostly wood home and deck with drains that lead to the creek and a pond in the middle of a wrap around deck. I don’t want to use SH and will be using sodium percarbonate instead. I was playing around with it yesterday on my fence and I downstreamed it making a mix of 8oz (volume not weight) on a 14-1 injector. Didn’t do much and after I found another thread on here by searching just percarbonate instead of sodium percarbonate I found a post that you should use a pump up sprayer or 12v to apply. Is that how you do it? Is that the right amount of sp per gallon? And if so is it weight or volume? Is there any special tasks to deal with the runoff? I noticed the mix bucket foamed like crazy (it was only 1 gallon) but wondering if I’ll have foam all over the place around the pond and home. I plan on doing a test area but want to learn as much about this product before hand as possible. Thanks in advance!

I’m confused… what makes sodium percarbonate okay to go down the drain in to the creek? What makes it better than SH? Also, can you not just use something to block off the run off from entering the drain?

Not intending on running off into the drain or creek by any means. Possible overspray into the pond is the main concern. I will be bagging the gutters for the roof cleaning using Sh. Mostly just wanting to learn about percarbonate as I never used it before.

Edit: from my research s percarbonate being an oxygenated form of bleach is safer to use around waterways as it dissipates quickly and won’t stay in the water as long? I say that with a question mark because I have not verified that statement…

Here is a video from the wizard of wood it touches mostly on sh and a bit of Sodium percarbonate: https://youtu.be/lsAsypUZZ_A
He has other videos that go into more depth about it, including one where he uses sh, sp and sodium metasilicate to clean the wood. I actually bought the metasilicate and his brightener, along with regular oxalic to test the differences myself. Hoping to try it out later today if I have the time.

@Seandz Spray it with a house mix to clean it and hit with oxalic acid afterwards to brighten it, unless your specifically tasked to restore wood don’t worry about wizard of oz, cleaning and restoration are 2 different things.

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I agree with the others. Just use sh and watch your over spray. A little over spray isn’t going to do much to a pond anyways. Plus, you’ll be diluting it down plenty when rinsing and that’s before it even gets to the pond. Even one of those small garden ponds would probably take quite a bit of sh to do any harm to anything. If it’s an actual pond I wouldn’t worry about it one bit.

As far as sodium percarbonate you won’t be able to dissolve enough of it in water to get a strong enough mix in order to down stream. It’s either pump up or 12 volt.

This guy has a little shallow pond with fish in it and it’s got a structure around it. Supposed to clean that. Thinking just low pressure rinsing with hot water or maybe there is an eco friendly soap I can use that is just soap only no bleach? Anyone use anything like that? Pics attached.

I’ve been end of year deer hunting so not looking at the phone. 8 pt came in but wasn’t quite a shooter, so hope to see him next year.
A couple of things: 1. Your dilution rate is going to be so high that between that and absorbtion, little if anything will effect the pond. 2. Everett, the Wizard of Wood knows his stuff and I use some of his products but as had been pointed out he is truly in the wood restoration business. His business model doesn’t work here in TX. He’s in NJ, paying union type money is normal, it’s not down here. I’d live to be able to charge enough to do the stuff he does, not happening. 3. If you are concerned (sounds like it) then sodium percarbonate is the way to go, using a 12v or pump up. I start with 8 oz of powder per gal of hot water and adjust from there. It takes longer than SH to work and usually done brushing but it does work. 4. SH is faster and cheaper, so if you can get the results you want and not be concerned about killing vegetation. Use it. Hope that helps.


I agree, his quotes work in that area, in my area it would never fly. Of course, 30 minutes away from him people are building million+ homes left and right.

Seandz - I don’t understand why you just don’t tarp the pond then use your SH? I have had Koi ponds before, those fish are pricks, unhappy with sun or shade or good bacteria, etc etc. Some large Koi are very pricey, so don’t kill any. I always start my pond off by sacrificing about 50 gold fish before I put the koi in, the gold fish will get the water right. tarp the center by using rods across the pond (convex would be good), if you don’t have any see if a pool guy will let you borrow some.

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Just saw this post thanks man. I ended up just spraying pure Sh all over the place and rinsing it down into the pond to dilute it. JUST KIDDING! I used surfactant alone with no sh at all. There wasn’t really any growth so green wash and warm water rinse worked perfect. I’ll keep that idea for the future though :rofl:

Thanks for the input man. You are the local pwra wizard of wood, been reading a lot of your info, great stuff!