Recipe for Wood Bleach?

Re: Recipe for Wood Bleach?

David Propst

>Hey Joel,

I don't have a recipe, but I bought two part bleach at Home Dept this afternoon. I'll try it tomorrow and let you know how it works. I have some really nicely spalted poplar with dramatic black lines. I want to see if the normal wood bleaches while leaving the black spalting. I also will try some walnut.

Of course this will be done in between completing my at least 3-year long "Honey Do" list before I start school Monday. I'll finish the laminate flooring tonight and start painting the den...

Best Regards,

David

lye and peroxide

John Trant (aka Boxes-n-Bowls)

>The ingedients in the packages of "2 part bleach" are hydrogen peroxide and sodium hydroxide (lye). I don't know the concentrations nor the proportions of the packaged preparations but I doubt it is too critical. I diluted my stock solutions of 1.0 M NaOH and 40% hydrogen peroxide (old stock so I doubt it was anywhere near that concentrated) but I don't remember the precise manipulations.

If I remember correctly, this bleaching method removed the natural colors from ash, maple, walnut and cherry but it did not bleach out spalt lines. I don't remember if the fungal "bluing" of maple and holly was eliminated.

I find it interesting that if you use lye alone(i.e., without the peroxide), it will darken ("age") cherry, walnut, and presumably other colored woods. Again, my stock solution is 1 M from which I dilute it 10-100 fold before use. I find that a more dilute solution overnight results in a more pleasing transition than a 15 minute treatment with a concentrated solution. Some do not neutralize after bleaching or lye treatment but I always do with a solution of sodium bicarbonate (baking soda).

John

Re: Recipe for Wood Bleach?

John Lucas

>Joel

I've used the 2 part Kleen Cut bleach from my local hardware. I've also used household bleach. The 2 part bleach seems to work better in terms of really lightening the color but you need to test it if possible. It will lighten some areas without changing the others on some woods.

Re: lye and peroxide

Jim DeLaney, Tustin, CA

>I find it interesting that if you use lye alone(i.e., without the peroxide), it will darken ("age") cherry, walnut, and presumably other colored woods. Again, my stock solution is 1 M from which I dilute it 10-100 fold before use. I find that a more dilute solution overnight results in a more pleasing transition than a 15 minute treatment with a concentrated solution. Some do not neutralize after bleaching or lye treatment but I always do with a solution of sodium bicarbonate (baking soda).

Baking soda will not neutralize lye. Both are Bas solutions. It takes an acid to neutralize a Base, and vice-versa. A diluted white vinegar will neutralize the lye.

Yes but no

John Trant (aka Boxes-n-Bowls)

>Actually, both weak acids and weak bases serve as excellent buffers because they can absorb or donate hydrogen/hydroxyl ions as required. The best buffers for any particular solution is one that has its pKa at or near the required pH (i.e., a buffering range of +/- 1 pH unit of its pKa). The pKa of a buffer is the pH at which half of the buffer molecules are ionized and half are not. The pKa for bicarb is about 6.2 therefore it will readily neutralize the NaOH. The reason bicarbonate is the preferred buffer for this procedure is because acetic acid is a relatively strong acid for a weak acid with a pKa = 4.8. So, yes, vinegar (acetic acid) will neutralize NaOH but you need to precisely monitor the situation or you will substitute the problem of too high of a pH with the problem of a pH that is too low. A bicarb solution (with its pKa near neutrality) can completely neutralize the NaOH without the worry of excess bicarbonate adversely lowering the pH significantly.

John

Professor,

Molecular Endocrinology and Physiology

Re: Recipe for Wood Bleach?

Ric Erkes

>Joel, let us know how it works. I have some Holly with the same problem.

Ric