We have what looks like a large water stain on the slate table from leakage of a plant. How do we try to remove it. Thank you
Dear Ted:
"
How do we try to remove it?"
You don't.
First off, your "water stain" is acid etching. Even if it was water from a plant, it was not pure water and it obviously it had picked up some sort of pH activity from the dirt and fertilizers in the vase. (Water can not - and in fact does not - stain.)
That said, unless the slate is ground flat and processed in the factory (like a chalk board, for instance) its surface is not workable. For two reasons:
1. The only way to process the surface of a stone is by grinding it with abrasive means. This can't be done on a somehow rippled surface like slate gets usually delivered with. (Natural cleft finish.)
2. That kind of finish is obtained by simply exfoliating the layers of slate and nothing else. In other words, unlike the finish of any other stone that's delivered flat, the finish of the surface of natural cleft slate is not produces by a factory, but is strictly from Mother Nature's kitchen; and no human can duplicate that with any kind of equipment.
Is there any solution?
The ony possiblity is to hide the discoloration.
How?
I'm pretty sure that if you wet the affected area with some water, that "water stain" disappears until the water dries. If that's the case, a good-quality stone color enhancer like MB-6 will produce the same effect in a permanent way. The whole table top will become darker than it is now, but it's your only option.