Rust stains on driveway

Talk women (or men), politics, gripe about your 6er (or other ride), and speak your mind.

Moderators: GRNSHRK, ron, bfons

Post Reply
User avatar
Sbeaud
Posts: 279
Joined: Fri Jan 04, 2019 9:38 pm
Location: Okahumpka, Florida USA

Rust stains on driveway

Post by Sbeaud »

As part of replacing my starter I ground down the outside of a socket to gain clearance (http://bigcoupe.com/phpBB2/viewtopic.php?f=2&t=32071). I did this grinding with an angle grinder on the driveway. Unfortunately the removed metal stained the driveway with rust - not what I expected. I've tried vinegar - that improved it, but the stain remains. Also tried "Multi-Use CLR" from Home Depot - didn't work. Anybody have success removing a stain like this?

Thanks

Scott
Driveway rust.jpg
Driveway rust.jpg (755 KiB) Viewed 1596 times
1988 M6
User avatar
hornhospital
Platinum Member
Platinum Member
Posts: 2929
Joined: Sun Jul 11, 2010 6:46 pm
Location: Silverhill, AL
Contact:

Re: Rust stains on driveway

Post by hornhospital »

I was going to suggest regular CLR, but I don't know if it would work any better than the "Multi-Use" version. I've never used that version, only the full strength CLR, and I've had good results with it.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
Jlc
Posts: 287
Joined: Sun Sep 27, 2020 5:27 pm
Location: Atl

Re: Rust stains on driveway

Post by Jlc »

Have you tried vinegar and lemon juice?
85 635CSi Bronzit
bpoliakoff
Platinum Member
Platinum Member
Posts: 3312
Joined: Thu Sep 28, 2006 9:28 pm
Location: scottsdale, arizona
Contact:

Re: Rust stains on driveway

Post by bpoliakoff »

Diluted pool acid. Dilute it very weak and increase the addition of the acid until you find the weakest mix it will work with. If vinegar didn't;t do it I think you will have to go that way
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
User avatar
Sbeaud
Posts: 279
Joined: Fri Jan 04, 2019 9:38 pm
Location: Okahumpka, Florida USA

Re: Rust stains on driveway

Post by Sbeaud »

Tried the vinegar/lemon juice combination.
Driveway rust-1.jpg
Driveway rust-1.jpg (136.23 KiB) Viewed 1548 times
Driveway rust-2.jpg
Driveway rust-2.jpg (134.87 KiB) Viewed 1548 times
It did improve, but the stain remains.

Bert - I think your suggestion is a good one. I always consider acid as sort of the nuclear option. I'll see if I can obtain a small amount. A quick look at Home Depot seems to have large containers. I only need a few ounces.

Thanks

Scott
1988 M6
bpoliakoff
Platinum Member
Platinum Member
Posts: 3312
Joined: Thu Sep 28, 2006 9:28 pm
Location: scottsdale, arizona
Contact:

Re: Rust stains on driveway

Post by bpoliakoff »

It's less than $5 a jug,I think, at Home Depot.At that price just get rid of the extra. How I don't know or where
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
Pod
Platinum Member
Platinum Member
Posts: 4492
Joined: Tue Mar 16, 2010 8:32 pm
Location: usually in the barn, Kent, England.

Re: Rust stains on driveway

Post by Pod »

Can’t see the rust on my drive due to all the oil 😂
User avatar
Sbeaud
Posts: 279
Joined: Fri Jan 04, 2019 9:38 pm
Location: Okahumpka, Florida USA

Re: Rust stains on driveway

Post by Sbeaud »

Finally got around to addressing this issue again. Burt, went with your nuclear option. Undiluted muriatic acid. The concrete is clean as can be, but the small stones still have a tinge of rust. I'm calling it good.

I also used it on a couple other rust stains on the driveway and walkway. Not sure the origin of those, but it worked well. Not sure what I'll do with all this extra acid though!

Thanks Burt!

Scott
Driveway Rust Stains - post Muriatic Acid.jpg
Driveway Rust Stains - post Muriatic Acid.jpg (4.64 MiB) Viewed 1324 times
1988 M6
Jlc
Posts: 287
Joined: Sun Sep 27, 2020 5:27 pm
Location: Atl

Re: Rust stains on driveway

Post by Jlc »

Keep it in case you need to clean concrete off your shark.

Click and Clack -Stump the Chump:

https://www.cartalk.com/radio/show/1222 ... ationships
85 635CSi Bronzit
User avatar
Sbeaud
Posts: 279
Joined: Fri Jan 04, 2019 9:38 pm
Location: Okahumpka, Florida USA

Re: Rust stains on driveway

Post by Sbeaud »

Unfortunately there's a pay wall for click and clack. But I can imagine they had some fun with that one!
1988 M6
Post Reply