Oxalic Acid (2 lbs) 99.6% Pure - Multipurpose Cleaner and Stain Remover for Wood | Metal | Stone | Concrete - Rust Remover - Wood Restorer - Deck Cleaner - (C2H2O4) - Durable Resealable Packaging.

We had rust stains on concrete sidewalks, driveway and vinyl siding. This product works as well as White Ox brand and is lower cost.

I used it to remove growth from the bottom of my boat.

Works as it should. Follow the directions. Wear gloves and pants it burns the skin. Do not inhale. Restores natural grain colors

I'm cleaning up some iron stains on an outdoor tile porch that have been there for many years. The stains are from the feet of iron lounge chairs and are pretty deep. I tried hardware store lime/calcium/rust remover and it had no effect. I put Oxalic acid on the tile for about 10 minutes and voila - the iron stains are completely gone. I don't know how toxic this stuff is, so I used thick rubber gloves and was careful not to get any on me. I wiped up the excess rather than flush it into the lawn. It also lightened the grout, which was pretty dull.

The best item I ever buy , it work great on my grout , I buy so many and none of them work as good as this ,I would buy again , I give 5 stars

Mixed 1/2 bag, guessing 5-6 cups in hot water and poured into my sump pump pit. Guessing about 5 gallons of water in pit. Let soak for 24 hours. Seemed to clean up my pit walls and and deposits on pumps. I didn't scrub anything and cleaned pretty well. May do this about once a year to keep things "cleaner" and limit rust deposits on pump and internals.

Worked well as a brightening agent in a pump-up sprayer in preparation for restraining my older cedar fence.Prior to using this using my pump sprayer, I applied a 1:1 ratio of outdoor rated chlorine bleach to water, then after 15 min rinsed off with my power washer. Then applied the Oxalic acid using the instructions on the pkg. Fence looked great when done and ready for staining.

Cleaned my 50+ year old wood floors great.