View Full Version : Removing blackened wood water stains


ohohyodafarted
11-13-2015, 08:57 PM
If you have a television cabinet with a light finish, blonde, pine, or walnut and it has an iron oxide water stain, this information may be of interest to you if you want to try and remove the stains.

I am in the process of starting the restoration of a CTC4 Cheltenham in very rare natural pine finish. AT some point the cabinet must have been in a storage area where water was dripping onto the top of the cabinet. The result was that the wood got black water stains in the grain of the wood.

In the past I have used "wood bleach" that can be obtained at the Ace hardware. The problem is that wood bleach is very agressive and not only will bleach out the dark water stain in the wood, it also bleaches the surounding wood and you end up with patches of wood that are lighter than other surounding areas.

I did some searching and discovered an interesting post on the web that addresses this kind of dark stain on wood in a manner that is gentle, and does not appreciably effect the color of the wood itself, but yet slowly pulls the dark iron oxide water stain out of the wood.

As it turns out the dark stain is caused by the iron particles in the water. The iron reacts with tannin in the wood and makes a black stain. The article says it is an iron oxide stain.

The article recommended using "Barkeepers Friend", a sort of cleanser, that contains oxalic acid. The Oxalic acid neutralizes the iron oxide stain in the wood.

The process is slow, and will take a number of applications depending on how severe the iron oxide stain in the wood is. In my case I used 4 applications on the top of the pine CTC4 Cheltenham, over a period of about 10 hours. It was very effective and it did not effect the color of the wood, it just neutralized the iron ixide stain..

The link below is to the article that shows the process being used on some natural teak. The teak had a very severe stain, but the Barkeepers Friend was able to remove it completely.

http://www.thomaspenrose.com/diy_stains01.htm

I strongly recommend this process if you need to remove iron oxide water stains from any light colored wood. I am sure it could even be used on a dark wood if there is a dark water stain you need to remove.

Kevin Kuehn
11-13-2015, 10:56 PM
You used to be able to buy Oxalic acid crystals in a bottle at your local drug store. You dissolve them in water to your desired strength. Seems like I've even ssen it at places like Menards, in the wood finishing department.

ChrisW6ATV
11-17-2015, 12:33 AM
Thank you for the notes and link, Bob. My maple-finish CTC-4 Gainsborough has a ring stain on it; it is not black that I remember (and the set is covered by a blanket right now), but this may be the trick depending on what I find when I start work on the set.

andy
11-17-2015, 08:57 PM
I bought a tub of wood bleach from the hardware store a couple of years ago, and it says it "contains oxalic acid". It worked well to remove a water stain from a radio cabinet without any other change in color.

ohohyodafarted
11-18-2015, 01:33 AM
I bought a tub of wood bleach from the hardware store a couple of years ago, and it says it "contains oxalic acid". It worked well to remove a water stain from a radio cabinet without any other change in color.

The wood bleach I bought came in 2 bottles. I don't know what was in bottle #1, but bottle #2 contained strong Hydrogen Peroxide and that is what bleached the color of the wood and made areas that were lighter in color than the sourounding area.

Sounds like the product you found was better than what I got at Ace.

cbenham
11-22-2015, 06:41 PM
If you have a television cabinet with a light finish, blonde, pine, or walnut and it has an iron oxide water stain, this information may be of interest to you if you want to try and remove the stains.



Thanks Bob, this is just what I've been looking for. The wood cabinet on a nice
stereo amp will soon look like new!

Findm-Keepm
11-23-2015, 12:11 PM
"Zud" cleanser also has ~10% Oxalic Acid in it - we used it to clean those black stains left when felt pads or foam pads deteriorated on lidded entertainment units - yes, blonde sets looked particularly bad with the stains. A Popular Mechanics article had details about removing stains from furniture, and that was the genesis of our use.

On a side note, it (Oxalic Acid) also cleans pitted chrome nicely. My '74 Civic bumper was in sad condition - 20 minutes with some Zud cleaned all the rusty pits back to a shine, and made the car look better (as good as a pregnant roller skate can look....)

andy
11-23-2015, 12:18 PM
The wood bleach I bought came in 2 bottles. I don't know what was in bottle #1, but bottle #2 contained strong Hydrogen Peroxide and that is what bleached the color of the wood and made areas that were lighter in color than the sourounding area.

Sounds like the product you found was better than what I got at Ace.

It sounds like the product you bought was designed to bleach the color out of wood (say for a blonde finish) rather than for removing water stains.