Hi - I don't have a lot of experience with this. My first thought would be to sand it off... However - I do get a woodworking magazine. The issue my wife just handed me has this: "Repair a water-damaged finish". The author Kevin Southwick - is a wood finishing specialist and furniture restorer in Minneapolis, MN. He opens his article with the following: "Watering a potted plant can be disastrous if the plant lives on top of something made out of wood. We've all seen the white spots and black rings that can result when water seeps through the pot. And if you've ever tried to sand out these marks, you know it's a tough job that can leave telltale depressions on the surface. Fortunately, in many cases, this type of damage can be almost magically undone by treating the wood's surface with Oxalic Acid. [end quote] I believe I've heard of this before, when researching refinishing hardwood floors... I know that you can use just plain bleach on hardwood floors (gently) to remove a lot of stains before refinishing. Anyway - I would suggest doing some more research on refinishing furniture, looking at hardwood floors; and possibly picking up the current issue of: American Woodworker (oct/november 2009) I reference you to page32 for the start of the article which I quoted from above. Hope this helps.

Start with mild soap and water on a damp cloth to get up the water-soluble stuff. Then do the same with mineral spirits and 0000 steel wool in any stuck spots to get the rest of the crud. Then use the Wood Preen as a finishing wax unless you are seeing bare wood. The dark and light spots are normal, and a waxing and buffing might be enough to get the floors into "cared for by a great housekeeper for half a century" look. The black spots might be ink spots. I could tell where the first owner of one house had his drafting table set up from the way the ink spots landed.

I just ran across this thread while looking on the internet for flooring to patch an old wood floor. Very interesting thread. Could someone tell me a good place on Garden Web to find a thread about removing sticks of the old floor and replacing. I found information on utube but not about how to figure how much flooring to purchase. Mine will need repair much like mrplows. I have one very bad area which will need thirty two 2 1/4 wide sticks. Each stick would only need to be 8 inches long which is because a wall was torn out and there was no hardwood under that wall. I will need to figure out how much wood to get to make the lengths varied. My other area needs fourteen of the 2 1/4 and each is 60 inches. I have a feeling I am going to need to purchase a lot of hardwood for the repairs. Thanks for any information.

You should really rub it in, and wipe excess off with a clean cloth. The same thing you would do if you used black shoe polish on your shoes or handbag. I think it is Kiwi black shoe polish I used, the flat can available at grocery stores. It did not produce a high shine on my slate, more like the original eggshell or satin finish. I had no problems with it rubbing off. In my opinion, it works perfectly.