Mold that grows on wood furniture is there because moisture is present, and mold may be just one of your problems. Fuzzy mildew deposits -- which are a type of mold -- usually grow in high humidity, but blackening of the wood that occurs after contact with water may be a combination of mold and water-damaged wood. The best way to remove the mold is to scrub it, but blackened wood may need treatment with wood bleach. Always wear a respirator and gloves while working with mold.
Mold Cleaning Solutions
Contrary to a widespread belief, chlorine bleach is not a particularly effective mold remover, especially not with porous materials such as wood. Instead, all you need is a solution of laundry or dish detergent and water. The solution should be as mild as possible because you don't want to damage the finish on the furniture. If you're having trouble removing mold from crevices and carvings, a paste made with baking soda and water is a safe cleansing deodorizer that acts as a mild abrasive.
How to Remove Mold
You have to physically remove mold from whatever surface on which you find it; spraying it with a detergent solution, vinegar or even bleach isn't effective. Scrub the mold with an abrasive sponge or a textured cloth, such as an old terrycloth towel. Frequently rinse the sponge or towel and change the water when it becomes black. To prevent the water from causing further damage to the wood or finish, wring the sponge or towel well before wiping and dry the wood with a separate cloth. Clean mold from crevices and carvings using a toothbrush.
Dealing With Water Damage
If the furniture has been in prolonged contact with water and the wood itself has turned black, this may not be caused by mold but by a chemical reaction between the wood and water. Removing this blackening is a job for bleach -- but not chlorine bleach. Instead, you need a wood bleach that contains oxalic acid, a type of oxygen bleach. Allow the wood to dry before bleaching and sand off any finish by hand with 120-grit sandpaper. Apply the bleach according to the instructions on the container, repeating two or three times if necessary to get all the black out. Neutralize with a solution of 1 tablespoon of baking soda per 1 quart of water, then wipe down the wood with clear water and allow the wood to dry thoroughly before staining and refinishing it.
Protecting Your Furniture From Mold
Mold spores are everywhere; it's impossible to prevent them from landing on furniture. They won't grow, though, if there is no moisture to support them. Furniture in dark, humid rooms is especially vulnerable, so if you have to store wood furniture in the basement, protect it by covering it with plastic. If you notice mold growing on a piece of furniture you're using, move it closer to a heating vent or run a fan to increase air circulation. Frequently wiping down wood furniture with a damp cloth and drying it with a dry cloth removes spores before they have a chance to root.