Editor’s note: This article was excerpted from Bob Flexner’s article “How to Remove Watermarks“
Photo: Jon Chase (The Wirecutter)
Light marks are milky-white and are caused by moisture getting into the finish and creating voids that interfere with the finish’s transparency.
To remove milky-white watermarks, you need either to consolidate the finish (eliminate the voids) to the point that the transparency is reestablished or cut the film back to below the damage. Success is not predictable, but in general, a white watermark is easier to remove in the following circumstances:
- The finish is newer.
- The shorter the time the watermark has been in the finish.
- The shallower the damage goes into the finish.
Here are the best ways to remove milky-white watermarks, arranged in order from the least damaging (and generally least effective) to the potentially most damaging.
Apply an oily substance
Apply an oily substance, such as furniture polish, petroleum jelly or mayonnaise, to the damaged area and allow the liquid or gel to remain overnight. The oil will often restore some of the transparency (by filling some of the microscopic voids) but seldom all of it.
Heat the finish
Heat the finish with a blow dryer or heat gun to soften the finish so it consolidates. This may restore some of the transparency if you get the temperature just right, but if you get the finish too hot, it will blister. Avoid getting the finish any hotter than is comfortable to touch.
Dampen a cloth with denatured alcohol
Dampen a cloth with denatured alcohol and wipe gently over the damaged area. The trick is to dampen the cloth just enough so it leaves the appearance of a comet’s tail of evaporating alcohol trailing as you wipe. (You can practice by wiping across a more resistant surface such as polyurethane or plastic laminate.)
If you get the cloth too wet, the alcohol may soften the finish too much and dull the sheen or smear the finish. This is especially likely if the finish is shellac (used on most furniture finished before the 1930s), but this technique is most effective on shellac.
Spray a light mist from an aerosol “blush” eliminator over the water damage. The solvent is butyl Cellosolve, which will dissolve lacquer and restore the transparency. Be very careful to avoid too wet a spray or it could damage the finish.
These aerosols are sold to professionals. You might find one at a distributor that caters to the professional trade, or you could spray a mist of lacquer retarder if you have a spray gun and can get it to the furniture or the furniture to it.
Cut through the damaged finish
Cut through the damage by rubbing with a mild abrasive such as toothpaste, or with rottenstone (a very fine abrasive powder available at most paint stores) mixed with a light oil. Fine #0000 steel wool lubricated with a light oil, such as mineral oil, is more effective because it cuts faster, but steel wool will leave noticeable scratches in the surface. Use steel wool only as a last resort.
Rub the damaged area until the water damage is gone, being careful not to rub through the finish. Then, if the sheen is different from the surrounding area, even it by rubbing the entire surface with an abrasive that produces the sheen you want.
French polish the damaged area
French polish over the damaged area using padding lacquer, another product sold to professionals. The lacquer-thinner solvent in the padding lacquer will soften the finish (the same as if it were wiped or sprayed on separately) and often clear up the damage. It may be necessary to continue polishing the entire surface to get an even sheen.
This technique works fairly well on surfaces in good condition, but it is risky on crazed or deteriorated surfaces. If the watermark doesn’t come out entirely with your initial application, you will seal in the remaining milky whiteness and make removing it more difficult.
If you have no experience removing milky-white watermarks, I recommend you try wiping with an alcohol-dampened cloth or rubbing with an abrasive. Both techniques are usually effective and the risk of serious damage is less.
– Bob Flexner
This article was excerpted from Bob Flexner’s article “How to Remove Watermarks”
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