It is often necessary to bleach a dark wooden piece of furniture when you want to re-stain it. You may also need to bleach wood in the case of water stains or if the color has become blotchy and uneven in areas so that you can give the wood a neat finish. Wood can be bleached with a two-component wood bleach or with oxalic acid.
Method 1 of 3: Prepare the surface
Step 1. Clean the wood thoroughly
Never apply bleach to dirty wood. Before bleaching the wood, wipe it with a soft cloth and water. Carefully remove any caked-on dirt and dust, then allow the wood to dry. You will usually need to let the wood dry for one to two days before bleaching it.
Step 2. Wear protective clothing
Bleach can be dangerous if you get it on your skin or in your eyes. Before applying bleach to the wood, put on safety goggles and thick gloves.
Bleach can stain your clothes, so it's always a good idea to wear old clothes when working with bleach
Step 3. Place or place the wood in a well-ventilated area
Always work in a well-ventilated area when using bleach to avoid dizziness and lightheadedness. Ideally, you bleach the wood in an open garage, on a terrace or in a garden. The chemicals in bleach have a strong corrosive effect and therefore it is better not to come into contact with yourself and the things in your house.
Step 4. Using a cloth or brush, apply a paint remover or stain remover
Such strippers are used to remove paint and varnish from wood. When bleaching wood, it is important to start with wood that is as clean as possible. How you apply it depends on the type of stripper, so read the directions on the package. Usually, you apply a stripper to the wood with a soft cloth, let it sit for a while, then rinse it off with water.
- Paint strippers are made on a chemical or citrus basis. Chemical strippers give off strong fumes, but can remove the paint within half an hour. Citrus based strippers have a less strong odor but are slower to work and may require multiple applications.
- You will usually need to let the wood dry for a day or two after using a paint or stain remover.
Method 2 of 3: Bleach with a two-component wood bleach
Step 1. Use a two-component wood bleach to bleach wood
If you just want to lighten the wood, a two-component wood bleach is the best option. This is a less aggressive agent that gives the wood a lighter color without drastically changing its appearance.
Step 2. Mix the two components together
Read the directions on the package to see exactly how to do this. Usually you mix equal amounts of the two components in a glass or plastic container. Make sure not to use metal, as bleach can damage metal.
Don't forget to read the directions on the package, because with some products you apply the components one at a time instead of mixing them
Step 3. Apply an even coat of wood bleach to the wood
Dip a clean sponge into the mixture to soak it with the bleach mixture. Using slow, firm motions, apply the wood bleach to the wood in straight strokes. Keep going until the wood is covered with the bleach.
If you intend to apply the two components one at a time, apply the first in this way first, followed by the other. Depending on the type of bleach you are using, you may have to wait a certain number of minutes before applying the second component
Step 4. Neutralize the wood bleach with a mixture of one part white vinegar and one part water
After applying the bleach, prepare a mixture that is half white vinegar and half water. Take a clean sponge and apply the mixture in the same way as the wood bleach to neutralize the bleach.
Some wood bleaches also come with a neutralizing agent. If that is the case, it is not necessary to prepare a mixture yourself
Step 5. Rinse the wood with water
Use a clean sponge moistened with clean water for this. Wipe the wood until the rinse water runs clear, making sure to remove all traces of bleach and vinegar from the wood.
Step 6. Let the wood dry
The drying time depends on the type of wood and the wood bleach you used. The directions on the packaging of the wood bleach should state how long you should allow the wood to dry. Only treat the wood when it feels completely dry.
Step 7. Sand the wood
Use a piece of sandpaper with a grit size between 320 and 400. When the wood is dry, carefully go over it with sandpaper. This smooths out rough spots and uneven grains.
Step 8. Neutralize the wood again
After you've sanded the wood, neutralize it a second time. Make a mixture of one part white vinegar and one part water and apply it to the wood. When you're done, rinse off the residue with water.
Step 9. Apply wood lacquer
Applying lacquer is extremely important to protect the surface of the wood and give it a nicer look. You can apply lacquer when the wood is completely dry. Purchase wood lacquer from a hardware store and apply the lacquer to the wood according to the package directions.
Also wear safety glasses and gloves when painting. The chemicals can harm your skin and the paint can sometimes give off harmful fumes. For oil-based products, use a breathing mask with a charcoal filter so you don't inhale chemical fumes
Method 3 of 3: Bleaching using oxalic acid
Step 1. In case of rust stains and weather damage, use oxalic acid
Oxalic acid should not be used just to change the color of the wood. It is best used if the wood is heavily damaged, for example if there is rust stains and damage due to weather influences, and you want to bleach the damage away.
Step 2. Mix the oxalic acid
The packaging should tell you exactly how to mix the acid. Usually you dissolve about 350 to 470 ml of acid in 4 liters of hot water.
Mix the oxalic acid in a glass container, rather than a metal or plastic container
Step 3. Wipe the wood with the diluted oxalic acid
Apply layers of acid to the wood with a sponge. Wipe a generous amount of oxalic acid on the wood to ensure proper bleaching of the wood. How many layers you need to apply depends on how wet you get the sponge. Apply enough coats to completely soak the wood with oxalic acid.
Step 4. Let the acid dry on the surface
When you work with oxalic acid, you do not have to stick to a certain drying time. Just leave the acid on the wood and check the wood regularly. When the wood has acquired the desired color, you can rinse away the acid.
Step 5. Rinse off the acid with clean water
Wet the wood with clean water using a sponge or cloth. Continue to wet the wood until the rinse water is clean and all the acid has been rinsed off the wood.
Step 6. Neutralize the oxalic acid with baking soda
Dissolve 2 tablespoons (30 grams) of baking soda in 1 liter of hot water. Pour the baking soda and water mixture over the wood to neutralize the acid. Repeat two or three times, then rinse the mixture off with clean water. Let the wood dry overnight.
Step 7. Sand the wood
Sand the wood when it is completely dry. Use a piece of sandpaper between 220 and 180 grit. Gently sand the wood to smooth out any uneven, rough spots.
Step 8. Apply wood lacquer
A high-quality varnish can help give the wood a nicer look and protect it from damage. Purchase lacquer from a hardware store and apply it to the wood according to the package directions. Allow the paint to dry completely before using the wood.