I recently picked up a round coffee table from an estate sale. It’s made of cherry wood. Right in the middle of the table, there was a big black stain about 4 inches x 10 inches. It looked like some sort of ink type stain to me. I used Jason furniture refinisher to remove the varnish. I have been applying clorox bleach on the stain. It has lightened up and it’s now a medium gray color. Would someone please tell me how to lighten up the stain some more or, better than that, how to get rid of this stain altogether?
If I manage to remove the stain or lighten it up considerably, what would be the best way to refinish it? Must I bleach the whole table top before applying stain? If the stain remain gray, do you think a brown mahogany stain (e.g. from the Bartley collection) would hide it?
Thanks in advance for your help!
Replies
You may have to move on to oxalic acid to bleach and then to the 2 part bleach. See how it evens out to know what next. It sounds like a severe water mark that has damaged the wood.
I doubt anything will "hide" it without making the wood muddy looking. Keep working to remove. Cherry will age/darken naturally over time. You may not want to stain it at all.
When you get the stain lightened up, wipe your surface with mineral spirits to see what the color will be if you apply a clear film finish. That will give you a starting point to think about.
Gretchen50,
Thanks so much for the advice. I'll follow your plan. Do you know where I may get oxalic acid? About the 2 part bleach, would you please elaborate? Does it mean to mix 2 part bleach with 1 part something? Clorox is ok? Sorry for the questions. But I've never done this before. THANKS again for the help!
You can get both at HOme Depot. Two part bleach is a specific product and VERY rough to use. Read the directions carefully.Gretchen
Thank you!
I went to the Home Depot asking for oxalic acid. The people in the paint department didn't know what I was talking about. I got a box of something that looks like the two part bleach. Can I just go straight to the two part bleach and skip the acid?
Thanks for your help.
The Big Orange Box doesn't have anything -- the most noticable thing they are lacking, in my opinion, is expertise.
Try a local hardware store or a quality paint store.
Cherry contains a high concentration of tannin (up to 4.5%). Tannins will react with iron to form insoluble ferric tannate which is black. It is also likely that because of the acidity of tannin, it could react with silver.
Oxalic acid will react with ferric tannate to form the colorless, water soluble ferrous tannate. The surface should be treated with one or more applications of a solution that contains one pound of oxalic acid to one gallon of water [preferably hot water].
(Obviously you don't need to make a gallon so simply follow those proportions for a more appropriate volume of solution).
After treatment you will need to thoroughly wash the surface to remove any excess oxalic acid and the ferrous tannate. If you do not, the ferrous tannate can revert to ferric tannate.
It is too bad you tried the bleach you did as a first step. All bleaches will remove color from wood and what you are now faced with is having to add color now to match the surrounding untreated wood. This problem might not have been as pronounced had you only carefully used the oxalic acid solution.
Stanley Niemiec -- Wood Technologist
Thank you for your advice. I'll try to call the paint stores in the morning about oxalic acid. Since I have already applied bleach to the wood, must I clean it with something first before applying oxalic acid?
If when wet you can still smell a residual of the bleach, then you need to rinse/wipe with damp rags.
I finally found Oxalic acid at Anawalt Lumber. It's labeled Wood bleach by Dap and the small prints indicate Oxalic acid. I have applied the acid a couple of times. I cleaned off all residuals, let it dry. etc. etc.
To make a long story short, as you expected, here's how the table now looks like. I'm in trouble. You can see the large area in the middle where the black stains were. I tried to bleach the area outside of it but I have not been able to give an even tone to the whole surface. Also, where the stains were, the wood feels a little rough, I think I might have tried to scrub it too hard.
Before I commit more mistakes, would you please give me some suggestions on what I may do so the color would come out even after I stain it? I have refinished (but never had to bleach wood or fixed stains) other pieces in my home using Bartley brown mahogany stain and varnish. I would like to use the same material if possible.
Should I continue with the bleaching (oxalic or clorox) or how I may "add color" as indicated in one of the instructions?
Thanks so much for any help you can provide.
The roughened surface is due to the swelling of the wood. It should be VERY lightly sanded with fine grit paper (eg 150 or 180) just enough to get it smooth.
Matching color is THE MOST DIFFICULT ASPECT OF WOOD FINISHING. Joyce Kilmer best stated it when he wrote that "only God can make a tree." Not only do you have to match God's work but you have to blend in the borders. And then there is the whole issue of chatoyance -- that from one angle the wood will have a particular color but at another angle, it will have another one (color) that is entirely different.
There are dyes that you can use (both alcohol and water based analines) as well as pigmented stains and glazes. These materials can be used on the raw wood, between coats of finish and in finishes. In all cases, you are going to have to use all in all combinations. It is going to be a lot of tedious detail work and then when you think you have got it right, in a different lighting condition (eg tungsten filament v. florescent v. sunlight) the colors will be different. When I get involved in situations like this, I basically end up regraining the area with fine touch-up brushes (similar to artist's brushes) and shading it with my air-brush.
What I have never tried is to obtain the color extractives from like wood, concentrating it and then applying that. I wonder if you could take a gallon or so of cherry sawdust, stick it in a big stainless steel pot with water to cover, and simmer the H_E_L_L out of it. The resulting liquid would certainly be cherry colored and if that fluid could be concentrated and then applied to the wood, you might get somewhat of a match????
Has any one ever tried this?
Thanks for your advices. I'll try your suggestions and apply a lot of patience. I'm learning a lot from this. In the end, if it does not look perfect, some books and magazines on top of it will do.
Again, I really appreciate your help!
From the pic you submitted, it looks like a solid cherry top. You might be able to take the top to a shop with a big belt sander and have them sand the top down until the stain disapears. I did this with a couple of Koa end tables that had horrible sun bleached damage. The results were wonderful. Both tables are identical now and are once again, proudly displayed in my living room.
Gretchen,
This is the current state of the cherry coffee table. I have applied oxalic acid, bleach, rinse, wipe, etc.. You can see the big white area in the middle. When the table is wet, this area is more prominent. Should I keep on trying to bleach the surrounding area? How may I be able to achieve an even tone when I stain it?
Thanks a lot for any advice you may have for me.
There is something about the jpg that doesn't quite look like cherry to me. I wouldn't expect that a furnature maker that was matching up a solid cherry top would use large streaks of sap wood in it. Stanley hasn't commented on it so I'm probably wrong. If it is a different wood, say birch with a cherry stain, there is no need to try to get a cherry color out of it. It looks like a solid top with no beading around the edge, so I would take a cabinet scraper to it and expose new wood over the whole surface. That should get you past the gray area and even out the color of the grain. I would guess that it had a so called 'cherry" finish on it and you should refinish it with any color of finish that you find pleasing.
BJ
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