I was asked to quote cleaning this deck. It has rust spots from some of the deck screws. Any advice on removing the rust without leaving any discoloration? The search bar only yielded one result on this subject, which mentioned using Naval jelly. I’ve never heard of this product before, does anyone have feedback?
Oxalic shouldn’t discolor the composite decking. I’ve used it on the same color you’re dealing with and it worked fine. I would still do a test spot in an inconspicuous area just in case the composite is manufactured different than what I cleaned. If for some reason it does lighten it a little you could just spray the entire deck once you’re finished removing the rust. Kind of like we do with concrete. I don’t think it’ll lighten though. If the oxalic doesn’t work you might need to step up to F9 Barc.
Naval Jelly is marketed to remove rust on steel so you’d definitely have to test that on composite before using it. It’s probably just some kind of acid, anyways.
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Thank you! I will try to remember to document the process and post some after pictures.
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Guess they didn’t use stainless screws, and didn’t screw through the tongues or use the clips, lots of different styles of composite.
I used naval jelly for rust on composite with success. I’ve had it take rust out in 10 seconds and another time with 10 mins of scrubbing and reapplying. No idea why such a big difference.
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I looked at the sds for Naval Jelly and it’s a lot stronger acid. It has phosphoric and sulfuric in it. It’s made for removing rust on steel so they go really strong with the acids. The phosphoric makes up somewhere between 10%-30% of the product. The sulfuric is less than 1%. F9 Barc uses between 1%-8% phosphoric acid if that says anything.
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