Bleaching to Remove Dye Stains
Adding alcohol to the solution may help remove some dyes, if straight household bleach doesn't do the trick. July 3, 2008
Question
I need to refinish a small cherry table I made. I stripped the finish, but I used a Transfast water dye on it and I want to remove it too. I thought Clorox would work, but I don't know how much to dilute it.
Forum Responses
(Finishing Forum)
From contributor C:
Don't dilute it - Clorox sodium hypochlorite will not bleach the wood in the traditional sense like two-part will. It will only bring it back to its pre-stained condition. If the Transfast dye is still present, then add a dye solvent to the Clorox. Try 20% alcohol - if it's still there, add some retarder also. Get back with the results - try a hidden area first to determine the results.
You can also try diacetone alcohol (Sherwin W.) at 10% to the Clorox.
Make sure you wash off the excess bleach with sterile/distilled water a couple of times after you're through bleaching. Dry with rags or paper towels.
From contributor K:
Interesting. I've never heard of adding alcohol to the bleach. What does this do?
From contributor C:
The diacetone alcohol actually opens up the wood more, allowing the bleach to penetrate a little deeper. The ethyl alcohol only helps if the dye by chance is soluble in polar solvents, which I believe Transfast, being a metal dye, is. The retarder is a glycol either which allows more open time for the sodium hypochlorate to react with the dyes/wood surface. None of those may be necessary. Use the Clorox first by itself. Only if all the dye is not removed are the others really necessary, like on the old world water dyes back in the 30's-40's, etc.
You can also resort to using pool chlorine which is much stronger than Clorox before using the alcohol/G eithers as additives - again make sure to wash off with plenty of clean water if you do!
From the original questioner:
Thanks! I tried some test pieces and the Clorox changed the natural color of the wood too much (kind of greenish), so I just sanded back the wood a little more and wiped it down with water instead of the bleach. Once I redyed it, the splotchiness evened out. This was just the top of a side table I made a couple of years ago. The woman got some deep scratches in it, but kept on putting her iced drinks on the scratched area (as well as burning incense), so the top alone was toast. Being the rest of the piece was fine, there were no hidden test areas. I think it will look fine.
From contributor C:
Glad you got it worked out. Were the samples you tried dyed or just plain wood? If just bare undyed wood, this is the reason you may have seen the greenish cast. If they were dyed, only the dye should have been affected by the bleach concerning the lightening affect.
From the original questioner:
The tests were on new cherry. Only half had the Transfast dye only on it. It all turned the same color, even though I rinsed it under a faucet. It wasn't dramatic, but significant color change. Maybe this is a cherry thing?
From contributor C:
No, it's not a cherry ting - it did as I'm familiar with, just did not give you what you were after.
PS: In the future, if you wash the dried surface off with water or scrub lightly with steel wool or scothbrite, this will eliminate most of the yellow green tinge from the chlorine residue left behind and leave a more pristine normal looking color of the wood surface. Chlorine naturally has a greenish yellowish tinge to it.
From contributor K:
I would think it best not to use steel wool as it may react with some woods like oak. The ScotchBrite pads are safer.
From contributor C:
We were talking about cherry, but you're correct.
