oxalic crystals

[Richard 17]

NO LAUGHING OUT LOUD

We got the contract to clean the concrete at a rather big College, as well as the parking lot sweeping/line painting. Yesterday two of us were there doing gum removal. I noticed a couple of heavy rust spots, so I tried some wood brightener (straight) on with about a 10 min. dwell. Absolutly nothing. Just thought I'd share that moment of stupidity.

Guess it's time to get the crytals.

[Keth 15]

Are you sure it was rust and not a battery acid stain?

[John Orr 206]

If it is battery acid, Prosoco Ferrous Stain Remover should work. They have another product - can't recall the name - that will remove acid burn. Check their catalog, or talk to your local supplier.

[Richard 17]

I can't picture it being battery acid, 3" X 2", In the middle of the walkway/entrance. Really dark orange/brown rust color. Heavy stain.

I've been noticing lots of pin head size rust stains in lots of concrete.

Any comments or sugestions????

[RyanH 14]

I can't picture it being battery acid, 3" X 2", In the middle of the walkway/entrance. Really dark orange/brown rust color. Heavy stain.

I've been noticing lots of pin head size rust stains in lots of concrete.

Any comments or sugestions????

Sure it isn' tannins in leaves or acorns from trees? I know they can both leave orange/brown stains on concrete here, some of them quite strong, but nothing that strong bleach couldn't handle.

[Richard 17]

Hi Ryan

Thanks for the input.

No, this was rust (I think). We are back there again on Sunday. I need to get someone to physicaly show me how to upload/download (or what you call it) pictures. I've never bought the crystals, but I pick them up Friday.

I'll "search" again to make sure I'm using the right mix and safety precausions.

[Mataman 14]

I can't picture it being battery acid, 3" X 2", In the middle of the walkway/entrance. Really dark orange/brown rust color. Heavy stain.

I've been noticing lots of pin head size rust stains in lots of concrete.

Any comments or sugestions????

sounds like overspray on the fertilizer containing iron to me

[RyanH 14]

Hi Ryan

Thanks for the input.

No, this was rust (I think). We are back there again on Sunday. I need to get someone to physicaly show me how to upload/download (or what you call it) pictures. I've never bought the crystals, but I pick them up Friday.

I'll "search" again to make sure I'm using the right mix and safety precausions.

Upload is when the file transfer originates FROM you...you send a file from your computer to someone else.

Download is when the file comes TO you...you receive a file from someone else, another server, etc.

If you are talking about transferring data between your computer and a PLC...the terminology is opposite for whatever reason.

If you want to post pictures, when you create a new thread click on the "Manage Attachments" button under the Additional Options area below the text box...in the Attach Files sub-area. From there you can select the location of the file on your machine and upload it to TGS.