Stripping and Bleaching Oak
After trying several suggestions, a finisher hits on the right solution to clean and brighten some old oak drawer fronts. November 11, 2006
Question
I've tried bleaching an old oak desk using oxalic acid to remove the dark stains, but it doesn't appear to be having much of an affect. I've tried various strengths, up to being unable to dissolve any more crystals. Any suggestions?
The two drawers pictured are different, but started with the same look. I first stripped them of yellow and red paint. You can see the oxalic crystals remaining on the bleached drawer. The area in the yellow circle still contains a gray cast I expected to be gone.
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Forum Responses
(Finishing Forum)
From contributor C:
Use the oxalic full strength (saturated solution), hot and freshly mixed. Make sure that you have removed all the finish first. The oxalic works pretty well but is not magical; it rarely removes everything that you'd like it to.
From contributor M:
Oxalic acid is considered a brightener, and in most cases is used after the wood has been bleached with either Clorox or the two part albino bleaches. It is used to brighten or lighten markings from metals and some other stains that were not removed from the bleach. Try using the Clorox on a small area - you will see the difference between bleaching and brightening.
From contributor T:
Oxalic works very well on iron oxide stains, which usually result from water standing on the surface. I think it would be hard to get water to stand long enough on a drawer front to stain it. Looks to me like something else spilled down the front. I'd try a chlorine bleach but if you do, get some swimming pool chlorine or some industrial strength bleach.
From the original questioner:
Won't bleach like Clorox remove the oak's golden yellow color? My goal was to remove the gray cast.
From contributor M:
Try the Clorox bleach first. In some cases it may take a few applications to get the color lighter. I can see it must have been a tough strip, but you must get the old finish off before going to a brightener or a bleach.
I just saw your latest post. Sometimes in finishing you have to go to plan B. When something doesn't work, you need to find a way around it. It's no big deal to lose the color; you just put it back later. From the look in the photo, there is too much color still in the wood. Try going to plan B - test a small area.
From contributor R:
Remove the drawer pull and the key escutcheon. Get a few brass bristle brushes. Put some solvent based stripper and lacquer thinner into a can. Get a rag and soak the drawer front. After a few minutes of soaking, get the brass brush and dip it into the stripper/lacquer thinner mixture. Apply firm pressure to the brush and scrub the drawer front back and forth with the grain direction. Complete one drawer. Keep the drawer front wet! When you're finished doing that, repost the picture and let's see what you have.
From contributor T:
It's 2 part bleach that messes with the natural color of the wood. Chlorine works on dyes and dye-like stains. It sometimes leaves the wood with a pale greenish/yellow caste, but as has been stated - lost color is easy to replace. As for the natural color of red oak, I've seen it all the way from a pale pink (weird) to light rust to almost colorless. The yellow you describe is most likely from the finish applied. Shellac can be amber, NC lacquer is amber and yellows over time, and good varnish is amber - I would expect varnish.
If you haven't already stripped them, you should. The fronts look like solid oak. Is the second drawer from the right side of the desk (where a dirty thumb would leave a dirty stain on the right side of the pull)? It also looks somewhat eroded on the right side of the drawer front. What's on the inside of the pulls? If they're pretty dark inside, you're probably dealing with many years accumulation of grime (aka patina). I suspect that contributor R is right - stripping and sanding could be the whole answer and you just need to refinish it with a good varnish - Sikkens or Waterlox. If for some reason you don't want to strip them, I'd suggest cleaning them very thoroughly with a mild TSP solution and MS or Naptha if they're varnished. Use a mild Dawn solution instead of TSP if shellac or lacquer.
From contributor M:
Another good after wash is 50% alcohol and 50% lacquer thinner.
From the original questioner:
I tried the 50% alcohol and 50% lacquer thinner and it worked great! Thanks. I used a brass wire brush and rag. Thanks also on the clarification of oxalic acid use. I had already stripped the drawers of red and yellow paint. Three applications of stripper and I had stopped getting more results. This is from an old university biology lab desk and it actually has eight of these drawers.
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