Indian sandstone "fossile" stain removal

andyfr · Post: # 37740Post **andyfr** Wed May 13, 2009 9:36 am

I am continuing to lay the 50m2 patio, started last autumn, and was sorting out the slabs. Some have really bad "fossile" staining and I wondered if there was any way to remove it. I know this is a feature of the fossile buff sandstone but on some it looks like someone has been drawing on them with a felt tipped pen.

Wed May 13, 2009 2:01 pm

turn the flag over and re dress the edges?

andyfr · Post: # 37747Post **andyfr** Wed May 13, 2009 2:05 pm

Unfortunately the stains are on both sides on some of them.

Pablo · Post: # 37755Post **Pablo** Wed May 13, 2009 7:20 pm

Nothing you can do unfortunatly your only solution is to use them for cuts in out of the way spots or get them exchanged.

andyfr · Post: # 37778Post **andyfr** Thu May 14, 2009 10:38 am

What causes the stain out of interest?

Pablo · Post: # 37781Post **Pablo** Thu May 14, 2009 7:41 pm

It's chemical reaction that happens when the stone is exposed to the atmosphere after millions of years buried.

henpecked · Post: # 37831Post **henpecked** Sat May 16, 2009 12:11 am

Pablo wrote:It's chemical reaction that happens when the stone is exposed to the atmosphere after millions of years buried.

Oxidisation is the term, :;):

Under ground, no oxygen, above ground, lots, all your iron, metals and anything else that got mixed in when it was formed start to decompose 'or' oxidize....

here endeth the lesson

HP