Need advise on how to lighten oak

[tim young]

I just purchased a pair of speakers that someone had put a soaked rag on the top of one of them. Not sure what was in the rag, but it is much darker than the light color of the oak speaker cabinet. Any ideas on what to do to lighten it? It is a veneer, so I have to be careful about sanding it. And even then, it may be stained through the veneer. Thank you, Tim

[Dave Gaul]

Is there any way to find out way could have been on the rag? It would be good to know that first so you know what type of solution to remove the stain with.

If not, I would start with mineral spirits and see if that removes it... if not, I don't know where to go next!

HTH

[tim young]

I asked the owner and he ddin't know what was on the rag. He bought them at auction and the rag was sitting on them. I tried thinnner and it didn't remove any of the stain.

[Steve Schoene]

Next option to try would be oxalic acid.

[Scott Holmes]

If the oxalic acid doesn't do anything; I would strip just the top and refinish it.

[Tony Bilello]

I agree with Scott about stripping however, I wouldn't expect much to change unless you are really lucky. Strippers usually strip off the finish but not necessarily the stain under it. Try it and hope you get lucky. If not, the next step would be to re-veneer the top. Without a frontal photo, we don't know how well a new piece of veneer will blend in at the line of demarkation between the front and the new top.

[tim young]

Here is a picture of the top. I'll try the oxalic acid to see if it works. Thanksstained top.jpg

[Lee Schierer]

To me that looks like an iron stain.

Here's some ideas on how to remove it: A simple test can be used to determine whether wood discoloration is caused by iron. Apply a saturated solution of oxalic acid in water or a saturated solution of sodium hydrogen fluoride (sodium bifluoride) to the stained wood surface.
If the solution removes the stain, then iron is present on the wood. If the solution does not remove the stain, try applying bleach to the stained area. If it removes the stain, the discoloration was probably caused by mildew.
If the iron stain is spotty, try to view the stained wood under a 10x magnifying glass. “Chunky” discoloration is usually a result of molten metal and looks like clinkers from a grinding operation. Stain that resembles slivers or flakes could be from steel wool. An even discoloration throughout the stain indicates that the iron was in solution when it contaminated the wood, probably in a contaminated finish.
It is easy to contaminate wood. For example, a wood processor routinely treated wood with a solution of oxalic acid to prevent iron staining, not realizing that the treatment tank itself contained iron, which contaminated the wood. Merely striking wood with a hammer can cause iron stain on some wood. It is best to cover the head of the hammer when nailing redwood and western redcedar siding.
Oxalic acid reacts with iron tannates to form a colorless complex. After treating wood with oxalic acid, thoroughly wash the surface with fresh, warm water to remove excess acid.

[tim young]

Thanks guys. Appreciate the comments and suggestions. I'll let you know how it goes this weekend. Tim