On Oct 25, 4:57 am, Andy Dingley wrote:
On 25 Oct, 01:50, Robatoy wrote:

Did you know you can stain granite if you forget to seal it?

In principle from empirical reports yes, but with my geologist's hat
on I can't think how you manage to do this. Granite is (or ought to
be) pretty tough stuff - impervious mineral grains that are closely
bonded without any sort of pervious matrix. Barring the odd mechanical
fissure, just how do you "stain" granite? What happens here - do the
grains change colour, or does some visible stain get absorbed into the
material? Which granites (chemically) are prone to it? What
substances will cause staining?

Malcom handled the bulk of the answer. It is the fissures that show up
as red lines, in the case of a merlot.
Large fields of granite will not stain, it's the fissy bit in between
that get you.
Plumber's putty on a black top......bad.
Red wine on a white-ish top...also bad. That creates lines of badness.

When you pour on sealant, just take a glancing look as to where it
soaks in first... There are way more fissures than one would expect.
The lower the grade, the worse it gets.