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Mykster
10-11-2002, 05:41 PM
What's a good way to get fert stains off of concrete?
Would bleach and a good scrub brush do the trick?


I just picked up a new client and she has stains on her driveway from the guy before who applied fert and didn't blow off.

What causes it to stain?

Bob Minney
10-11-2002, 05:52 PM
Most likley iron stain.
If you need to get rid of it quick-pressure wash & concrete cleaner.
Over time weather will fade it.

MATTHEW
10-11-2002, 07:54 PM
If you are talking about orange stains, it is very likely to be rust from iron chips!

I have seen it before. At the facilities that produce the concrete the machinery has iron parts that shred particles into the mix. It then begins to rust after a while and forms orange spots.

Fert will not permanantly stain any surface.

Let the blame falls where it belongs.

Darb
10-11-2002, 10:39 PM
The best way to get rust stains out is with some form of acid. I recommend Oxalic acid. You can find it in the supermarket in a product called "Bar Keepers Friend" (this is mild) or in some hardware stores called "Snowball" (much stronger) or "Snow cap" or something like that... if you go into one of the smaller older (Non-Home Depot type) they will help you out. Remember to use it when the concrete is dry and wet it in if you have to. If the concrete is wet before hand the acid will not have as much contact with the rust and therefore will not have much effect.
Darb

grassguy_
10-11-2002, 11:15 PM
I've seen this before, in fact have some experience with it as well, oops! LOL. The best way to clean the iron stains from the concrete is to use some muratic acid, commonly sold at pool supply shops. Be extremely careful by using gloves and stay clear of vapors from the bottle when you open it, can knock you for a loop if your not careful. I took a spot spray bottle with a dilution about 3parts acid to 1 part water, and spot treated the stains by spraying the acid on the stains, then brush with a normal shop broom and hose with water immediatley. Stains gone, does a good job. Agian be very careful with muriatic acid, and keep out of reach of children!

Alan
10-12-2002, 02:33 PM
Originally posted by MATTHEW
If you are talking about orange stains, it is very likely to be rust from iron chips!

I have seen it before. At the facilities that produce the concrete the machinery has iron parts that shred particles into the mix. It then begins to rust after a while and forms orange spots.



I'm not real sure where that bit of information came from, but were it a universal truth we would have orange sidewalks, bridges, roads, etc. Pretty hard to explain in light of all the light gray concrete I see everywhere, even after years of exposure.

MATTHEW
10-12-2002, 09:38 PM
That bit of info came from a concrete contractor.

I was blamed for the orange spots on a newer walkway because my Pendimathalin was orange. I knew that I blew off the walks and that even if it did stain it, the sunlight would have faded it by summer.

I checked around and this was my finding.

I'm sure newer facilities have black iron, steel or stainless equipment. But some have solid iron machinery. Once it mixes with the slurry it will not be removable.

I would not post a comment that was a waste of space.

f350
10-13-2002, 03:35 AM
i can walk on my new sidewalk and see this, mattew is right.

LAWNGODFATHER
10-13-2002, 08:39 PM
I am behind Matt also, they replaced my sidwalk last summer, and it had orange stains on it also. They are not from iron in the fert.

The Iron stains from iron in fert will only last a couple of weeks, the stains from iron chips in concrete will keep apearing as they are embedded in the concrete.

Alan
10-13-2002, 10:22 PM
There must be a major difference in the equipment used in kiln and grinding operations taht produce Portland cement here in the far northeast. I spent several years in the concrete construction business and still deal relatively often with other contractors who do concrete work. We never see the sort of staining you're describing. Might it be possible that the culprit is iron deposits in the aggregate rathen than the cement? Our common stone here is a hard limestone which is almost universally used as the crushed aggregate in concrete production.

Greg Amann
10-21-2002, 08:02 PM
Iron stains are orange and doesn't readily come out without multiple applications of a product called Rustaid or something similar. I'm not sure of the active. One application to painted stucco, vinyl, etc. Several applications to porous concrete. Manganese stains black. To avoid this problem with granular applications get with your fertilizer producers to use "granusol" iron & manganese in your mixes. We have ours custom blended and it is in the specs. to only use "granusols" so we don't have that problem.
Granusol is a mollasses coating that prevents those particals from breaking down to quick so a blower or wind or rain can wash them into areas that won't cause the staining.

Greg Amann
10-21-2002, 08:03 PM
Iron stains are orange and don't readily come out without multiple applications of a product called Rustaid or something similar. I'm not sure of the active. One application to painted stucco, vinyl, etc. Several applications to porous concrete. Manganese stains black. To avoid this problem with granular applications get with your fertilizer producers to use "granusol" iron & manganese in your mixes. We have ours custom blended and it is in the specs. to only use "granusols" so we don't have that problem.
Granusol is a mollasses coating that prevents those particals from breaking down to quick so a blower or wind or rain can wash them into areas that won't cause the staining.

MATTHEW
10-21-2002, 09:40 PM
So, what, you didn't blow the walks?

:dizzy: