Clean It Up

UK General Cleaning Forum => General Cleaning Forum => Topic started by: ray l on April 21, 2007, 10:35:04 am

Title: weed killer
Post by: ray l on April 21, 2007, 10:35:04 am

Hi all

One of my customers has brown marks like rust marks on concrete slab path

She says they appeared after a feed and weed was put on the grass.

Would pressure washing take this off or is there a chemical needed.

Thanks in advance
Ray

Title: Re: weed killer
Post by: BDCS on April 22, 2007, 09:00:36 pm

Hello, I have come across these marks myself and although jet washing will improove them you will need some brick acid to remove them

Title: Re: weed killer
Post by: Roger Oakley on April 23, 2007, 05:19:42 pm

Ray,
Oxalic Acid will get rid of the stains, but you would have to do the whole area not spot clean them, Oxalic works as a brighter as well so you would have a bright/white area where  the Oxalic has been applied. Easy to use, but you would need PPE with this one. Don't try any bleach as you will set the stain and make it even harder to remove. If you don't like the sound of oxalic acid you could try phosphoric acid, you'll find this in some Aluminium cleaners/degreasers.

Title: Re: weed killer
Post by: steve k on April 23, 2007, 07:53:10 pm

some moss killers have ferrous sulphate as the active ingredient which is iron...causes rust stains on hard surfaces.
Do not use acid on York flags...causes horrendous white/orange stains which you will not remove.

Title: Re: weed killer
Post by: Roger Oakley on April 24, 2007, 06:53:22 am

Quote from: steve k on April 23, 2007, 07:53:10 pm

Do not use acid on York flags...causes horrendous white/orange stains which you will not remove.

And don't use an acid on Indian Sandstone either, you'll get same results horrible orange stains that won't shift, as you will have marked the stones. The advice I gave earlier was for concrete only Ray.

Title: Re: weed killer
Post by: Jet Cleanse Ltd on April 24, 2007, 08:02:03 am

Hi,

What weedkiller would you use on block paving after cleaning or does this staining not happen on paving?
Thanks

Title: Re: weed killer
Post by: steve k on April 24, 2007, 08:21:45 am

one without Ferrous sulphate in it. It will cause rust staining on block paving.
Use a weedkiller suitable for paths. This has been developed as a direct need for non-staining weedkillers on hard landscaping.

Title: Re: weed killer
Post by: Jet Cleanse Ltd on April 24, 2007, 05:07:12 pm

thanks steve

Title: Re: weed killer
Post by: BDCS on April 24, 2007, 10:03:36 pm

I use glypohren

Title: Re: weed killer
Post by: Ged on April 25, 2007, 06:33:31 am

roundup ( glyphosphate)applied 2 weeks ahead of clean. systemic action kills roots so weeds don't return. doesn't stain,  non poisonous to pets and people. if you use a lot it is available as a concentrate from chemical suppliers.

ged