Refinishing Old Oak Floor..... Dark Spots.....

[Doug Richardson]

We are currently refinishing an old oak living room floor. We intend on staining the floor to a dark walnut, to more closely match the Brazilian Walnut flooring we have purchased for the kitchen. The floor is all sanded and ready for the stain, the only problem is that the oak flooring has dark spots that bleach, peroxide, or even oxalic acid will not remove. Do any one of you have any other suggestions on what to use to try to remove these stains, or any good tips on how to apply the stain to cover or blend in the dark spots? Thanks in advance.....:confused:

[Tom McMahon]

Swimming pool bleach is a stronger chlorine bleach. Stronger than that is the two part bleach that is hard to find. If neither of those work, route out the stain and glue in a dutchman.

[Howard Acheson]

What type of sander did you use? Was it a commercial floor sander or did you use a small hand sander? Small electric hand sanders will not do an adequate job.

Any idea what caused the stains?

What finish was on the floor originally and was the floor carpeted?

Any stain left on/in the wood will show up when you re-stain and re-finish the floor. You need to get it out or paint or carpet the floor.

[Doug Richardson]

What type of sander did you use? Was it a commercial floor sander or did you use a small hand sander? Small electric hand sanders will not do an adequate job.

Any idea what caused the stains?

What finish was on the floor originally and was the floor carpeted?

Any stain left on/in the wood will show up when you re-stain and re-finish the floor. You need to get it out or paint or carpet the floor.

1) Commercial floor sander. 36 -> 50 -> 80 grit.....

2) I was not there when it happened, but I would guess it was either cat or dog urine, or R. Kelly slept on our living room floor.....:p

3) House was built in 48, so I would assume a varnish, and yes, the floor has been carpeted for at least 30 years..... with the same carpet!

The planks are a non-standard flooring size now a days (1 1/2" tongue & groove), and even tho I have made replacement planks in my shop for it. this would require way too many to be worth the labor. and $3000 to replace the flooring in the living room and dining room is not in the current budget.....

[Jamie Schmitz]

There are strong bleach's that are I believe peroxide based? They are very strong so do a sample spot.

http://www.superfpaint.com/products/Wood-Kote-Lite-N-Up-Wood-Bleach.html (http://www.superfpaint.com/products/Wood-Kote-Lite-N-Up-Wood-Bleach.html)

[Doug Richardson]

In the upper right in this picture you can see how dark some of the the stains are:

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I went to Menards and purchased 2 packages of Zinsser Wood Bleach. I applied the solutions to the areas yesterday. Here is a picture of the same area this morning:

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I have not sanded the area yet, which you are supposed to do to remove the residue, but I think you can see that there is a noticeable difference. You can apply it as many times as needed to lighten it further, if needed. I may have solved my problem. Thanks for the suggestions!.....

[Howard Acheson]

Pet urine is an almost impossible problem. I've never seen a good clean-up for it. Many pet shops sell chemicals that they claim will work. The couple I've seen tried did not do a complete job.

You can Google "pet urine removal" and you will find lots of techniques and products. I have no info about any of the techniques or products.