white stain seeping out of a course

[mondyman]

Ive got a real ugly white stain seeping out of one course of bricks i've laid...

i'm told it's effervescence from contaminated sand....it's started to calcify now and looks real unsightly..

I've tried a wire brush..no joy...anyone know of anything that will remove it...
Cheers Mondy

 

[stuart45]

It could be lime run off. Calcium hydroxide is a by product of cement mortar. If the wall gets wet it can run out on to the wall and form hard calcium carbonate by absorbing CO2. Acid will break it down.

 

[ajrobb]

Did you keep your bricks dry before laying the course?

 

[mondyman]

Hmmm im preety sure i did but cudn't be 100% as some might have been laid out the night before , as to the brick acid....anyone know what it's called and where it can be bought...

It's definately calcified as i can scrape the large runs with a chisel and it turns to dust ..

Cheers for replies lads

 

[PrenticeBoyofDerry]

Linky
http://www.diydoctor.org.uk/projects/efflorescence.htm

 

[stuart45]

To remove hard lime I have always used a strong spirits of salt solution.
I brush it only on to the stained areas. To leave it to fade away on it's own would take a long time. I could show you walls where the lime run off has been on for at least 20 years. It's different from normal efflorescence.
Another method is to rub the area with a hard brick, but I don't personly use this method.