Sanding to Remove Mill Glaze on Wood — Is it Effective?

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Mill glaze, often an unseen obstacle on freshly milled lumber, can be a source of frustration for both DIY enthusiasts and professionals. It can lead to issues such as poor stain adhesion and compromised finishes. 

So, I’ve created this comprehensive guide to the process of sanding to effectively remove mill glaze. You’ll learn valuable insights and techniques to achieve a smooth and well-prepared surface for your upcoming woodworking projects.

Can You Sand Mill Glaze Off?

There are two primary techniques for effectively removing mill glaze from wooden surfaces: gentle pressure washing with a specialized wood deck cleaner and meticulous sanding.

With the right techniques, these two methods can effectively remove mill glaze off. Light sanding can successfully eliminate both mill glaze and fuzzy residues with the right precision, without inflicting damage on the wood.

On the other hand, over-sanding may lead to scratches and a weakened surface. In addition to enhancing the wood’s aesthetic qualities, light sanding also opens the pores.

sanding wood mill

This allows for better absorption of oil-based finishes and protects against common issues such as algae, mildew, and mold growth.

Once the sanding process is finished, it’s vital to thoroughly eliminate all remaining sawdust using a blower or vacuum, since even small amounts can negatively impact staining, resulting in an uneven, less durable finish.

By adhering to these guidelines, you can confidently tackle mill glaze and achieve outstanding results for all your woodworking projects.

How to Test Your Wood for Mill Glaze

Identifying mill glaze on a wood surface is an uncomplicated procedure, achievable through a basic water test. Initiate the process by moistening the wood surface with water droplets or a garden hose, then closely examine how the water interacts with the surface.

If the water forms beads rather than spreading out or absorbing into the wood, it is a strong signal that mill glaze is present. When the wood surface exhibits water-repelling properties, it is recommended to perform light sanding to effectively remove the mill glaze.

removing mill glaze from wood

Regularly conducting this water test, ideally every 2-3 months, helps maintain the optimal condition of your wood for future projects. It ensures that your wood surface provides an ideal foundation for any subsequent staining, painting, or sealing procedures.

Embracing this proactive strategy for wood maintenance can save valuable time and effort in the long term, ultimately contributing to more successful and gratifying woodworking projects.

Choosing the Proper Sandpaper Grit to Remove Mill Glaze

Selecting the appropriate sandpaper grit is a critical aspect of effectively addressing mill glaze, as making the right choice can significantly influence the outcome of your project.

Opting for the wrong grit size might inadvertently damage the wood or render it unsuitable for its intended purpose. Drawing from practical experience, it is generally recommended to use a grit size finer than 80 for the successful elimination of mill glaze.

Utilizing 80-grit sandpaper affords sufficient penetration to break through the mill glaze layer without compromising the wood surface. It is crucial to sand in the direction of the grain to avert the appearance of undesirable sanding marks.

preparing grit paper

To facilitate your decision-making process, I have assembled a comprehensive guide below that delineates various sandpaper grit sizes and their corresponding applications.

The following information will help you determining the optimal grit size for your specific project, ensuring that you achieve the desired results while maintaining the quality and integrity of your wood:

Sandpaper Grits


Superfine 360-600

Remove tiny marks

Extra fine 280-320


Very fine 220-240

Sanding between layers of stain

Fine 150-180

The last step before finishing

Medium 80-120

Preparation for finishing, removing mill glaze, removing stain

Course 40-50

Swift elimination of rough substances

Extra Course 20-30

Quick elimination, scuffing the surface

Understanding the relationship between grit numbers and grain size is essential for selecting the appropriate sandpaper for your wood project. A higher grit number corresponds to smaller, finer grains, while a lower grit number represents larger, coarser grains.

The finer the sandpaper grit, the smoother the finish it produces on the wood surface, making it ideal for projects that require a polished, delicate touch.

sand grit and wood

Conversely, coarser grits with lower numbers are best suited for rapid material removal and initial surface preparation, where a less refined finish is acceptable or even desired.

As you progress through a woodworking project, you may need to transition between different grit sizes to achieve the desired finish.

Starting with a coarser grit, you’ll effectively remove rough spots and imperfections, then gradually move to finer grits to create an increasingly smooth surface.

This step-by-step approach ensures that the wood is evenly sanded and that any irregularities or defects are effectively addressed. Moreover, it helps to reduce the risk of over-sanding, which could potentially damage the wood or compromise its structural integrity.

How to Sand and Remove Mill Glaze

Before initiating the sanding process, it is imperative to have the necessary tools at your disposal, which include:

preparing sanding materials

Once your tools are in place, take the time to prepare the workspace by eliminating any glue residue on the wood surface and wiping it clean with a microfiber cloth, ensuring a uniform sanding experience.

While sanding, exert light pressure and move the sandpaper along the wood grain to minimize the risk of scratches. Opt for 80-grit sandpaper, which should effectively eliminate the mill glaze during the sanding process.

Continue sanding until you reach the desired visual appeal, ultimately yielding a smooth, radiant surface devoid of mill glaze.

After the sanding process is complete, meticulously clean the wood with a microfiber cloth, eradicating all traces of sawdust. Adhering to this step is crucial, as any residual debris can lead to an uneven finish or adversely impact the quality and longevity of the paint job.

wood sanding

How to Remove Mill Glaze From Pressure-Treated Wood?

In addition to sanding, another highly effective technique for removing mill glaze from pressure-treated wood entails utilizing a wood deck cleaner in tandem with light pressure washing.

Start the process by diligently scrubbing the wood surface with a stiff brush, aiming to dislodge any entrenched debris or dirt.

Subsequently, carry out gentle pressure washing, which is frequently considered more convenient and health-conscious in comparison to sanding, primarily due to the elimination of sawdust generation.

Once the pressure washing phase is finished, let the wood air dry entirely. Occasionally, you might encounter residual fuzzy materials that necessitate light sanding for their complete removal.

The occurrence of these residues can be attributed to minor mishaps or inconsistencies during the pressure washing procedure.

brushing wood

Notably, this method is equally effective for cedar and pine wood, presenting a versatile solution for tackling mill glaze on a wide range of lumber types, ensuring optimal results for your woodworking projects.

Can Pressure Washing Help Remove Mill Glaze?

Pressure washing stands out as an efficient and reliable means of eliminating mill glaze from wooden surfaces. To do this, combine the use of a specially formulated wood cleaner and a high-quality pressure washer.

Start by thoroughly scrubbing the wood surface with a stiff bristle brush to dislodge any dirt, debris, or buildup that may be present. Following this, apply a wood stripper to the surface, which will aid in breaking down the mill glaze and facilitate its removal.

Proceed by pressure washing the surface with care, ensuring that the mill glaze is entirely eradicated and the wood surface is left clean and smooth. As a final touch, apply a wood brightener to the treated area.

This product not only elevates the wood’s overall appearance but also revitalizes its natural color and accentuates the inherent grain patterns. The result is a beautifully rejuvenated and visually appealing wood surface that showcases the material’s true character and charm.

Thompson water seal clearing application

Can You Use TSP to Remove Mill Glaze?

Certainly, trisodium phosphate (TSP) [1] serves as a highly effective agent for eradicating mill glaze from wooden surfaces, offering an efficient and thorough approach.

To begin, prepare a mixture consisting of one part TSP and three parts water, taking care to blend the components well.

Once ready, pour the solution into a garden-style pump sprayer, which will facilitate easy and controlled application. Generously spray the wood surface with the TSP solution, ensuring that the mill glaze is adequately saturated and covered.

Allow the solution to work its magic and penetrate the mill glaze for approximately 20 minutes. This soaking period is essential, as it enables the TSP solution to break down the mill glaze effectively and loosen its grip on the wood.

Following the soak, utilize a pressure washer to meticulously rinse away both the TSP solution and any lingering mill glaze residue from the wood surface, ensuring a thorough and complete cleanup.

removing mill glaze on wood using TSP

Once the entire process is finished, allow the wood ample time to air dry, giving it a chance to return to its natural state.

Employing this method not only eliminates mill glaze efficiently but also rejuvenates the wood, resulting in a refreshed, clean appearance that accentuates its inherent natural charm and aesthetic appeal, providing an optimal foundation for further treatment or finishing.

How to Remove Mill Marks From Lumber?

To effectively remove mill marks from lumber, begin by methodically sanding the entire surface using an 80-grit or coarser sandpaper, carefully eradicating all traces of visible marks while maintaining the integrity of the wood.

Once this is complete, switch to a finer-grit sandpaper to delicately sand the surface, achieving a smooth, uniform finish that showcases the wood’s natural beauty and enhances its aesthetic appeal.

During this stage, pay special attention to detail and ensure even coverage for the best results. Lastly, meticulously clean the surface, using a combination of vacuuming, air blowing, and wiping with a microfiber cloth.

lumber wood

This ensures the removal of any residual sawdust and debris that might otherwise impede subsequent treatments or finishing applications.

By following these steps, you not only successfully eliminate mill marks, but also elevate the overall appearance and quality of the wood.

This will create a pristine and well-prepared surface that is primed for further enhancements or final touches, resulting in a superior outcome for your woodworking projects.


How do you remove the old glaze from the wood?

To remove the old glaze from the wood, clean the surface, apply a chemical stripper, and let it sit as per the manufacturer’s instructions. Afterward, gently scrape off the softened glaze using a plastic scraper or steel wool.


Sanding to remove mill glaze is a crucial step in ensuring a flawless finish for your woodworking projects. By adhering to the expert tips and techniques outlined in this guide, you can effectively eliminate mill glaze and prepare a smooth surface for staining or painting. 

Remember that the choice of appropriate tools and a meticulous approach are essential for achieving the best results.

Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You've probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.
Robert Johnson

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