I have sanded the top of an oak parquet coffee table, and got rid of the crazing treacle brown varnish that covered it. Turns out the oak is a lovely golden shade BUT a nasty black mark is now visible. No idea what is is/was, but apparently metal + water could have had that effect because of the tannin in the oak. I shall go and get a photo.
To get rid of the stain, Googling brings up suggestions of boric acid (I think that is poisonous and unobtainable, but could be wrong) or toothpaste - Pepsodent was mentioned, but presumable other makes are equally good.
Does anyone have any advice?
Anger management!!! Help needed.