The Why and How of Bleaching Cherry Wood

Cherry wood is known for its rich, reddish-brown color that lends a warm, luxurious look to furniture and woodworking. However, furniture makers, woodworkers, and homeowners sometimes wish to lighten cherry’s natural pigment to achieve a more neutral, blonde, or whitewashed appearance. Bleaching is a process that can strip away some of the color compounds in wood to lighten its hue dramatically.

Bleaching cherry wood matches it to other lighter woods for a cohesive look. It also lets the beautiful grain of the cherry stand out in bolder relief. Additionally, bleaching enables staining the wood to different custom colors after the original pigment is removed. There are various methods of bleaching wood, from chemical solutions to sun exposure.

However, not all woods respond the same to bleaching. Cherry’s open, porous structure makes it a good candidate, while closed-grain woods like maple are poor choices. Understanding the bleaching process, careful preparation, proper techniques, and adequate safety precautions are key to successfully transforming the shade of cherry wood.

An Overview of Bleaching Wood

Bleaching wood is lightening its natural color by removing or altering certain color compounds within the wood. According to Bob Flexner in Understanding Wood Finishing, the main pigments that give wood its color include:

  • Tannins – Provide a yellowish or orange-brown color
  • Lignins – Contribute a yellowish hue
  • Dyes – Provide a reddish, purplish, or brownish tint

Bleaches work by oxidizing the wood pigments, breaking down the large color molecules into smaller, colorless ones. Common bleaches for wood contain chemicals like oxalic acid, sodium hydroxide, hydrogen peroxide, and/or sodium hypochlorite. These agents penetrate the porous wood structure and react with the color compounds.

Repeated applications remove more pigment until the desired lightness is reached. However, bleaching also degrades wood fibers, so caution must be taken not to over-bleach. Once satisfied with the color change, a clear finish should be applied to protect the bleached wood from absorbing dirt and oils that can return a yellowish cast over time.

Best Woods for Bleaching

Some woods’ porous, open-grain structure makes them better candidates for successful bleaching than dense, closed-grain woods. According to The Coastal Oak, ideal woods for bleaching include:

  • Cherry – Its reddish-brown pigment can be lightened significantly.
  • Cedar – Responds well to reveal lighter beige and tan tones.
  • Red Oak – Bleaching reduces the pink/salmon undertones.
  • Mahogany – Bleaching lightens the reddish cast.
  • Rosewood – Removes the rich brown coloration.

Woods with very dense, closed grains like maple, birch, and alder do not absorb bleach well and will not lighten much. The porous structure of woods like oak, cedar, and cherry allows deeper penetration. Testing bleaches on scraps first is advisable to gauge suitability.

Bleaching Cherry Wood – Step by Step

Supplies Needed

  • Chemical wood bleach (oxalic acid or sodium hydroxide base)
  • Plastic containers
  • Clean cloths
  • Soft-bristle brush
  • 220-400 grit sandpaper
  • Rubber gloves, eye protection, mask
  • Good ventilation (work outdoors is ideal)

Preparing the Cherry Wood

Proper preparation is crucial for cherry wood to absorb the bleaching agent effectively. Follow these key steps:

  • Lightly sand the wood with 220-400 grit sandpaper to remove any existing finish/stain and smooth the surface. Open the grain for better penetration.
  • Wipe cherry wood with a cloth moistened with mineral spirits to remove sanding residue. Let dry completely.
  • To remove darker stains, a vinegar and water solution (1:1 ratio) can be scrubbed as a pretreatment. Rinse thoroughly and allow to dry before bleaching.

Applying the Bleach

With safety gear on and working in a well-ventilated area, follow the product instructions carefully. Here are some general tips:

  • Use a plastic container and soft-bristle brush to apply the bleach solution onto the cherry wood gently. Keep the surface wet for 5-15 minutes.
  • Allow sufficient time for the wood to dry completely between bleaching sessions. Lightly sand again to open the grain before reapplying.
  • Multiple applications are usually needed, allowing the bleach to penetrate and interact with the wood pigments fully.
  • Let the wood dry in direct sunlight during the process. The UV exposure helps accelerate the lightening.
  • Repeat the bleaching steps until the desired level of lightness is reached. Take care not to over-bleach, as that can damage wood fibers.
  • When satisfied with the new color, rinse the wood thoroughly and allow to fully dry before applying a protective finish.

Post-Bleaching Finishing Recommendations

It’s important to apply a clear finish to the bleached wood for protection and to help lock in the new color. Recommended options include:

  • Polyurethane – Water-based or oil-based polyurethane will seal the wood and protect from dirt, oils, and potential re-darkening. Multiple coats are advisable for maximum durability.
  • Wood Wax – Hard or soft wood waxes also help stabilize the new color and provide a smooth, low-luster sheen. Work the wax into the porous structure for the best penetration.
  • Oils – Tung oil or Danish oils give light surface protection. Several applications are needed to build adequate sealing of the wood pores.
  • Shellac – As a seal coat, shellac helps prevent uneven blotchiness if staining the bleached wood a new color.

Alternative Bleaching Methods

While chemical bleaches are the most aggressive for maximum lightening, there are some alternative options:

Sun Bleaching

The ultraviolet rays in sunlight help break down wood pigments gradually over time. Allowing wood to sit in the sun for several days can naturally lighten it a few shades without chemicals. Ensure it’s protected from rain and dew. Consistent direct sun exposure works best. This passive approach takes much longer than using chemical bleaches.

Hydrogen Peroxide

Hydrogen peroxide can also lighten wood when repeatedly applied as an alternative bleach for delicate surfaces. Use 3% concentration, testing first for any discoloration issues. Let the peroxide solution sit for 20 minutes before wiping off and allowing the wood to dry between applications. Results won’t be as dramatic as stronger chemical bleaches.

Wood Filler

Applying a wood filler after sanding can help mask and lighten darker stained regions for small surface areas or tight spots. Opt for filler matched closely to the bleached color wanted. Allow to fully cure before sanding flush. Use filler sparingly so it blends in seamlessly.

Safety Precautions When Bleaching Cherry Wood

Chemical wood bleaches involve caustic substances, so it’s imperative to take safety measures when using them:

  • Work in a well-ventilated outdoor area and avoid breathing fumes. Use a mask if working indoors.
  • Wear gloves, eye protection, and protective clothing to avoid skin and eye irritation.
  • Carefully follow the manufacturer’s instructions for proper handling, mixing, application, and cleanup.
  • Never mix different chemical bleaches, as toxic fumes can result.
  • Store bleach products securely in original containers in a cool location away from children and pets.
  • Dispose of used bleaching solutions appropriately. Don’t pour them into soil, groundwater, or sewer systems.

With responsible use, certain wood bleaches provide an effective way to dramatically transform the appearance of cherry by removing its reddish-brown pigment. But careless use can lead to health hazards or permanent damage. Learn the proper techniques and take adequate precautions for beautiful, safely bleached wood.

Frequently Asked Questions

Is bleaching more effective on solid wood vs. veneer surfaces?

Bleaching works optimally on solid wood boards since the chemicals can penetrate deeply and uniformly into the porous structure. Veneered surfaces have very thin wood layers glued over substrate material, so chemicals don’t penetrate as effectively. Bleaching veneer runs a higher risk of an uneven, splotchy outcome.

Can you lighten just certain areas of a wood surface?

It’s very difficult to bleach only specific regions of a continuous wood surface selectively. The chemicals spread and diffuse through the porous structure. Precise taping and masking can help somewhat direct the bleach, but variation in results should be expected. Complete refinishing may be needed if bleaching is unsatisfactory.

Does bleaching remove wood grain?

No, bleaching does not eliminate or obscure the natural grain pattern – it merely strips away some color pigments. In fact, bleaching can make the grain stand out more distinctly on cherry and other open-grain woods by revealing the texture beneath the wood.

How long does bleached wood take to dry between applications?

Allowing the wood to dry between bleaching sessions is important for best results. Drying times vary based on factors like temperature, humidity, ventilation, and wood thickness. For reference, 1-inch thick cherry lumber may take 12-24 hours to dry fully. Thinner boards may dry in 4-6 hours. Speed drying by allowing good airflow.

Can you bleach wood that has already been stained?

Yes, existing stain and finish need to be completely removed by sanding/stripping before bleaching wood. The porous structure needs to be opened up for the chemicals to penetrate. Bleach will not effectively lighten wood on top of solid stain or finish. Refinishing is required prior to bleaching.

Is there a limit to how light cherry wood can be bleached?

There is a point of diminishing returns where more bleaching fails to continue lightening the wood because nearly all extractable pigment has been removed. Excessive bleaching degrades wood cell structure without significant color change at this stage. For cherry, the lightest achievable tone is a very pale blonde/white depending on original color.

What’s the difference between wood brighteners and bleaches?

Wood brighteners contain gentler hydrogen peroxide to lightly clean and “brighten” the natural tone of wood. Brighteners do not dramatically change color like bleaches. Brighteners remove dirt, oils, and surface stains acquired over time to restore the wood’s original shade and glow.

Can you bleach wood floors or furniture without refinishing entirely?

Spot-bleaching finished wood is not advised. Refinishing the entire surface is best for even bleach penetration and color results. Additionally, most floors have aluminum oxide finishes that require sanding for full removal. Bleaches will not work effectively on top of existing finishes.

What are some environmentally-friendly bleaching alternatives?

Oxygen bleach (sodium percarbonate) provides effective bleaching without harsh chemicals. Vinegar solutions also help brighten wood. For the most eco-friendly (but very slow) option, allowing wood to naturally sun-bleach outdoors gradually lightens tone through UV exposure.

Is it possible to reverse wood bleaching if the results are unsatisfactory?

Unfortunately, there is no easy way to reverse bleaching wood once it has occurred. The only option is refinishing by either staining the wood a darker color to mask the bleaching or completely removing the bleached layer by sanding and re-applying new raw wood veneer.

Can you apply a dark stain over bleached wood?

Bleached wood provides a neutral, light-colored base that can be successfully stained darker. The porous structure is opened up to accept the new pigment readily. Some woods may absorb stain unevenly after bleaching, so conditioner/pre-stain helps ensure uniform absorption.

What kind of clear coat works best for protecting bleached wood?

Oil-based polyurethane provides the most durable protective seal for bleached wood. Multiple coats ensure maximum sealing of the porous structure. Water-based polyurethane also works well. For light protection, tung oil, Danish oil, or hard paste wax help stabilize and maintain the bleached color.

How long will bleached wood maintain its light color before absorbing dirt and darkening over time?

With a quality topcoat applied, properly bleached and finished wood can retain its light tones for years with limited maintenance needed. Using dark wax helps hide superficial scuffs. Bleached wood will gradually pick up some patina with age like any natural material. But proper prep and sealing maximize durability.

Conclusion

Bleaching effectively transforms the appearance of cherry by removing its reddish-brown pigment to reveal lighter blonde, tan, or whitened tones. When done properly, the wood’s beautiful grain can stand out in bolder relief against the neutrally lightened background. But bleaching cherry wood requires careful preparation, repeated applications, adequate drying times, and safety precautions for ideal results. Understanding suitable methods, applying proper technique, and taking preventative measures will lead to safely and successfully bleached wood. With its porous structure and rich pigments, cherry is an excellent candidate for dramatic lightening by a bleaching process.