Bleaching black stain in maple

[bfwhitma]

Is there any new development on removing stain from maple

I am crushed that gorgeous maple burl mildewed during drying

Last time one method failed and other caused a pink stain when finished
Brad

 

[hockenbery]

Some stains don't react to bleach.
Two part bleach might lighten it. If you are returning it you will turn some of the stain away.

When I bleach spalted maple the black spalt lines stay black and pop out.
When I bleach ambrosia maple the ambrosia turns a strange green color.

I just had a small maple bowl get some bad mold because I missed days 2&3'where I did not change it to dry paper bags. I stopped the mold with a Clorox wash but the mold left lots of dark blotches.
I think it may all turn away on the second turning. If it doesn't, I may try bleach or I might just use black leather dye.

 

[Bill Boehme]

The two part bleach that consists sodium hydroxide and hydrogen peroxide bleaches wood, but is completely ineffective on mold stains. Oxalic acid is the normal bleach for mold stains. It may require several applications. Any kind of bleach only works on the surface so the piece must be finished including final sanding before bleaching. After bleaching very light sanding is acceptable to remove raised grain.

 

[Leo Van Der Loo]

Neither the 2 part or the oxalic acid will effectively remove the mold stains in my experience, oxalic will work on rust/metal stains but not so much on black mold stain.

It turns away if that is what you intend to do, however when wanting to keep a natural edge/surface it is not a solution.

In a case or two where I did get Maple burl with the staining already present under the bark, I just left the black coloration, as you can see in the picture, I didn’t think it was objectionable .

 

[Charlie Knighton]

If the mold stain is spotchie let wood dry completely, do some embellishments with gesso......

 

[Bill Boehme]

While at the hardware store this afternoon I saw some household mold and stain removers like Zep. X-14, and Tilex. If you have any of those on hand, you could see how well they work. If they will clean grout then they ought to be at least somewhat helpful on wood.

 

[Raul McCai]

Tilex is just Sodium hyporchlorite ( chlorine or bleach) in an aqueous solution
Zep is the same thing with a little bit of potassium hydroxide

I have no idea if this stuff works, but it sold as a mold stain remover
http://concrobium.com/products/stain-eraser/
I have never used the product.

here is the MSDS so it ain't just bleach
http://www.concrobium.com/wp-content/uploads/2012/06/Mold-Stain-Eraser-MSDS.pdf

It has sodium percarbonate which is dry granular form of Hydrogen peroxide; in an aqueous solution it'd have been reconverted to hydrogen peroxide. So If that works why not go to the local Hair Salon and buy a strong hydrogen peroxide solution and see if that works.

 

[Bill Boehme]

It has sodium percarbonate which is dry granular form of Hydrogen peroxide; in an aqueous solution it'd have been reconverted to hydrogen peroxide. So If that works why not go to the local Hair Salon and buy a strong hydrogen peroxide solution and see if that works.

The hydrogen peroxide that is used to dye hair is stronger than the 3% drug store peroxide, but it still isn't the industrial strength stuff that you need when bleaching pigment out of wood (not good for stains). Go to a pool supply store that sells either Baquacil Shock Oxidizer or Aqua Silk Shock Oxidizer. Either of those is 27% and a gallon is about $20. It is used in conjunction with a 2 molar solution of sodium hydroxide (lye) to bleach much of the natural pigment color out of most domestic hardwoods and softwoods. However, this combination will not bleach out spalting, mold, nor mineral stains.

For mold stains a strong chlorine bleach seems like the best shot at having success, but I haven't actually tried it.

The Forest Products Laboratory has an old report on their site about bleaching wood. I posted this tutorial on bleaching wood and then learned that an article in American Woodturner a couple years earlier said basically the same thing. My main interest was bleaching figured maple and I am very pleased with the results which turned the wood paper white. I also bleached a redwood plank and the early wood turned as light as maple while the late wood was bleached somewhat, but not nearly as much. The most spectacular results was on FBE (flame box elder). The wood turned snow white and the red stain turned from orange-red to almost glow in the dark bright red. 🙂 It's been about nine months and the red is still bright red, but it may have gradually faded slightly.