Knowing how to bleach wood can save a piece of furniture that is too dark, stained, or just needs an update. If you are comfortable with basic finishing techniques, you should have little difficulty bleaching wood yourself. Bleaching wood only works if you know the correct bleach to use for the stain or type of wood that you are bleaching. Oxalic acid is used for stains that are created when a wood that is high in tannic acid receives a water stain.
Mahogany, cherry, and oak commonly get these types of stains which can easily be removed with careful application of oxalic acid. Using oxalic acid also ensures that the wood around and underneath the stain is not lightened, preventing the need for treating the whole piece.
Chlorine bleach can be used to lighten stains that are caused by dye. Although many do it yourself websites may recommend using the same bleach you use for laundry, consider using calcium hypochlorite. This chemical comes in dry form and is often used in swimming pools. It is more effective than laundry bleach, and should require fewer coats to remove as much of the stain as possible.
Peroxide bleaches are commonly available in most home improvement stores and are intended to lighten a darker wood several shades. It may be called A and B bleach because it is two chemicals, sodium hydroxide and hydrogen peroxide, that are mixed together right before applying it to the wood. This is the bleach that most homeowners use when refinishing a piece.
No matter which bleach fits your intended project, there are a few tips to remember. Safety when refinishing your piece of furniture should be paramount, so be sure to wear gloves, a face mask, and eye protection. Working in a well ventilated area is also essential: a garage with the garage doors open is often a good option.
Plan on using a good quality paint brush to apply the bleach you are using evenly to the area you want to lighten. Check every 15 minutes after the bleach is applied until your piece reaches the desired lightness. Rinse off the wood with water after the bleaching is finished.
After 10 hours, if you still seek a lighter shade, you should rinse off the wood and then reapply your bleach to further lighten the piece. Keep in mind that after three applications the wood may not become any lighter- there are limits to the amount of pigment you can bleach out of the wood.
If it is as sunny day, you may consider bleaching the wood in stages, using the sun to enhance the effectiveness of the bleach. To do this, treat only one side of your furniture at a time and place the piece you are bleaching in full sun with the bleached side up. The sun will cause the bleaching action to become more potent, so it is important to check the piece often as well as record how long it took to bleach the side to the required color. Then you can repeat the process with the other sides.
Bleaching wood is a good tool to update furniture, but reconsider doing this work yourself if you have an antique or expensive piece. A professional refinisher should be able to present the best options to lighten wood and remove stains will retaining the value of your furniture.
