Oxalic acid

Ok so even here on this forum, I’m finding lots of opposing answers. So I want to know the best process for cleaning a greyed fence with lots of black. Should I use just a house wash mix and then rinse? Or then apply oxalic acid? Or use only oxalic acid? I did a fence last week with a mix slightly stronger than my normal house wash mix, applied it with my roof pump and the results were minimal. What do you think?

I think if the wood has a stain you should spray sodium hydroxide let it dwell then wash then spray oxalic acid let it dwell then wash… I think that’s how I read it in another post…now if it don’t have a stain I know u use a bleach mix just don’t know what type of bleach mix

Go read this post. Fence question - #17 by Racer - Wood Restoration - Pressure Washing Resource

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Thanks racer going to save this and right it down…

I went back and referenced that thread but I can’t find anything about mix ratios for hydroxide. Also, what’s the best way to apply it? DS? Pump sprayer?

What ways have you experimented with, what ratios, and what where your results?

I haven’t. Just haven’t had the time. I know the answer can vary widely, but I’m just seeking a general starting point.

Start with a little and keep mixing. After a month or two of trial and error you will be good to go.

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What would you define as a “little”? 4oz per gallon? 6oz per gallon?

I use flakes and mix my own liquid so my dry ounces may different than yours. Get some old pallets, buy different stains and apply to pallets. Make different strength mixes and x jet, ds, and punp spray them. You will know all you need to know in a few months and will be beholding to no one. Great feeling.

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