How to remove water stains from Oak

[Doug Carpenter]

Help?

I am repainting an old 3 panel Pella sliding door. I am going to refinish the sill as well. It is oak and has some black stains from water. I have stripped it of any finish that was present but it was so dry I think the last time it had a finish on was when it was installed in the fifties!

Can anyone suggest a way to remove or lighten the dark stains?

[Tony Bilello]

Mis some oxalic acid with water and form a heavy paste. Paint this paste thickly over the black rings. Place a slightly wet rag on top and put a very warm clothes iron on the rag for a minute or so then do it again. Remove the oxalic acid and see how well you did. If you still have ring, mix up a new batch of oxalic acid and repeat. This time get a little braver and raise the heat of the iron.
When you have removed 90% of the ring, the rest should come out with a light sanding.

[Doug Carpenter]

Thanks, I'll give it a try.

[phil harold]

+1 on the Oxalic Acid

[Tony Bilello]

Actually, the black stains on oak are usually from contact with some form of iron.The iron reacts with the tanic acid in the oak when wet and creates a black dye. The source of the metal was probably an old can.
Whatever the cause, the Oxalic will remove it.

[Howard Acheson]

Actually, the black stains on oak are usually from contact with some form of iron.The iron reacts with the tanic acid in the oak when wet and creates a black dye. The source of the metal was probably an old can.
Whatever the cause, the Oxalic will remove it.

The tap water in many places contains enough iron oxide to react with the tannic acid in oak.

[Mr Mike Mills]

I Teach cabinetmaking to high school aged students. I had a student who's OAK project was turned a little dark or black in color from some water. The water came from a hand cart that was used out side. The snow was still stuck to the tires, and as it melted the water ran towards this students project.

This is not the 1st time I have seen Oak do this.

Lightly sanding the wood did not seem to be working very well, and could not sand to much on part because they were plywood. After doing a little bit of research I tried to find a few solutions. There were many suggestions available on line. I thought I would try 2 of them . one spot on the left was deck cleaner. It worked okay, but not as well as a house hold cleaner I found. Also the Deck cleaner sure smelled like bleach. Deep into one online form at another site a user mentioned using “WHINK” Rust Stain Remover to remove black from where Iron had touched the oak The spot on the right. After work I stopped by my local home improvement store “Menards” and low and behold they did have the cleaner in stock.

http://www.sawmillcreek.org/attachment.php?attachmentid=279713&d=1389569876&thumb=1 (http://www.sawmillcreek.org/attachment.php?attachmentid=279713&d=1389569876)http://www.sawmillcreek.org/attachment.php?attachmentid=279714&d=1389569877&thumb=1 (http://www.sawmillcreek.org/attachment.php?attachmentid=279714&d=1389569877)



Now I have only had the opportunity to see if it would remove the stain, I have not tested the area to see how it will take stain, or a lacquer or sorts.


I sure hope this helps others with the same problem