After sanding on oak floors, some dark stains showed up and would not go away after repeated sanding. Any suggestions on getting these up before the poly goes on? WE believe them to be water stains - we do not believe them to be pet urine as they did not smell. Please help!

water stains can and normally do go deep into the wood. Board replacement is the answer, try to pull some wood from a closet or from under a staircase if possible for the best match.

Thanks for the reply. I appreciate you giving me the answer!!!! Not really sure that we are up to that but at least I now know that more sanding won't do the trick.

Gina,


A fellow remodeler told me he has had good luck with bleaching out dark stains. The dark color is actually mold/mildew and the bleaching will take care of it. I haven't tried it yet, though I am looking forward to it since most of the 100 yr old douglas fir floors in the kitchen have black seams when I refinish them.

If you try it, I would start with a weak solution and work your way up. Put a damp towel over the area to allow it time to work without drying out. Of course, keep in mind it may lighten the floor and it may look worse...

Anyone else ever try this?

Bleach will break down the wood fibers and with dug fir thats not what you want to do. Bleaching is ok for a small spot here or there but what I have seen most of the time is the bleach leaves a halo around the old stain so work progressivly from the inside out toward the edges.

IVE USED BLEACH AND IT WORKS FINE. JUST MAKE SURE YOU ADD A FIRST SEALER COAT.