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.

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.

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