clean stain on concrete?

[tenndigger]

What is the best way to clean a stain off concrete. Outside of my home garage we were parking the electric golf cart. It sat for a month or two and when moved it left a reddish brown stain on the concrete. I have a 4000psi pressure washer and have tried simple green, laundry detergent, grease lightning, and elbow grease with a heavy brush. These solutions didn't work. I do have some On and Off a boat hull cleaning product that has a burning effect if you get it on your skin. Should I try this?

[rlitman]

Well, in my book, cleaners that burn the skin work better than ones that don't, but if that stain is rust based, muriatic acid is a common answer. That stuff will do way more than just burn your skin though. The appropriate precautions for handling this are more than I'm looking to type right now.
Line-away is a slower acting, but safer alternative.

[Roof Cleaning Virginia]

Well, in my book, cleaners that burn the skin work better than ones that don't, but if that stain is rust based, muriatic acid is a common answer. That stuff will do way more than just burn your skin though. The appropriate precautions for handling this are more than I'm looking to type right now.
Line-away is a slower acting, but safer alternative.

If the stains are iron oxide (rust), try Super Iron Out from Lowes or HD. I haven't tried it but saw it work wonders on a video by a colleague.

[Pat Konen]

What is the best way to clean a stain off concrete. Outside of my home garage we were parking the electric golf cart. It sat for a month or two and when moved it left a reddish brown stain on the concrete. I have a 4000psi pressure washer and have tried simple green, laundry detergent, grease lightning, and elbow grease with a heavy brush. These solutions didn't work. I do have some On and Off a boat hull cleaning product that has a burning effect if you get it on your skin. Should I try this?

Were you able to get the stain out?

[tenndigger]

I haven't attacked the stain in several months. I did not try the boat cleaner. I am almost ready to get the boat out of the water, clean and store it. So it did cross my mind to get this cleaner out and use it. Over the summer the stain has faded and not very noticeable.

[Ric]

.

I am a Fert & Squirt Pesticide guy and every so often get fertilizer stain on concrete. I found the Oxalic acids like Rust Erase or Super Iron Out not only remove the stain but has no collateral damage to the run off turf.

On Black top roads I have had a spills or equipment breaks that leave a stain. I have found the commercial cleaning acid do too good of a job and leave the black top shinny black. However straight household Vinegar applied over 2 or 3 application a day apart removes the stain without leaving the street shinny black in that area.

Be super careful around Pavers. Cleaning acids not only remove stain but also the color from the paver brick if they are not sealed on a yearly bases.

I have also found Vinegar and Washing Soda does a nice job as a soft wash.

No I don't pressure clean commercially so my advice is more Homeowner or Wives tale. But it works for me.

BTW I recently found the source for the same chemical formulation of the Marine Alumibright used to clean pontoon boats etc. I am buying it for about 10 times cheaper than what the Marine stores are asking for it. I may just go into the Pontoon Boat Cleaning business

[tenndigger]

Thanks for the info. I didn't even think of trying the vinegar and baking soda. There is a basic chemical reaction there that should assist in the cleaning. I do agree that there are some alternatives to the expensive commercial cleaners. The On/Off hull cleaner is caustic and the directions recommend caution but it does a good job of getting stains off boat hulls.