Rust stains on composite decks

[Jersey Bill 17]

I just got a job with a small bue/gray composite deck. The owner believes its Trek. The have several small to medium size rust stains from their outdoor furniture. I would like to know what people are using to get rust off composite decks. The Trek website lists the following for rust stains:

Use a cleaning product containing oxalic or phosphoric acid, also know as Deck Brightener, to lighten or 

remove rust or dirt. Product may need to sit on the stain for 10 – 15 minutes before rinsing.**

 

If I were to use Oxalic acid should I treat the whole deck or just the rust stain?. Is there a mix ratio I should use?  I would appreciate any advice. Thanks.

[Beth n Rod 1,279]

Phosphoric acid is what is in Naval Jelly that attacks rust.

 

Problem is, it could also cause a problem with the composite in removing the stains at high concentrations.

 

Let the customer know this is possible and have them sign off on it.

If YOU void the warranty by doing this, YOU are liable for replacement.

 

Another possibility, replace the peices affected if the product isn't too old.

 

Rod

[Jersey Bill 17]

Rod,

Should I apply Phosphoric Acid to just the area of the stain or the whole deck?  

[seymore 90]

Sounds like it's the old composite?  http://www.trex.com/trex-owners/care-and-cleaning/

[Beth n Rod 1,279]

Just to the affected areas.

Brush and rinse.

 

Rod

[Jersey Bill 17]

I used Naval Jelly on the rust stains and it did lighten the stain a lot. I only left it on for 3 minutes while I brushed it in. After I cleaned the entire deck with my 12% mix. I rinsed it down and did a pass with pressure. When I got done I could barely see them. I didn't even bother applying a second application to the stain.

[MDBBALL02 2]

Ok ... I'm just a little homeowner, not a contractor, but I AM WOMAN HEAR ME ROAR!  LOL  I figured out how to get Rust stains, that were left from my wrought iron furniture, off my Trex (2nd generation) light gray composite deck planks ......READY????  A simple and cheap Hydrogen Peroxide and Baking Soda paste you can make, and an old toothbrush!  IT WORKS!  (I came to this site looking for a solution or recommendation and didn't so I started trying different things myself and WHOLA!  Hope this helps!  Each stain took me about 10 minutes, to scrub with this paste, but they all came up! Good Luck!

[Beth n Rod 1,279]

On 5/31/2017 at 11:47 AM, MDBBALL02 said:

Ok ... I'm just a little homeowner, not a contractor, but I AM WOMAN HEAR ME ROAR!  LOL  I figured out how to get Rust stains, that were left from my wrought iron furniture, off my Trex (2nd generation) light gray composite deck planks ......READY????  A simple and cheap Hydrogen Peroxide and Baking Soda paste you can make, and an old toothbrush!  IT WORKS!  (I came to this site looking for a solution or recommendation and didn't so I started trying different things myself and WHOLA!  Hope this helps!  Each stain took me about 10 minutes, to scrub with this paste, but they all came up! Good Luck!

Good to hear but it would depend on the severity of the rust to do that. Those elements are not active on rust typically. You got lucky. Acid is the way to go. Try tennis ball feet on wrought iron in the future, or clear coat with a Rustoleum product.

 

Beth

[njcathy 0]

I used Starbright Hull Cleaner (for boats) and with a little scrubbing it the small rust spots came off my AZEK