How to Remove Mill Glaze from Cedar Siding Without Fuzzing the Grain

Fresh cedar siding may look smooth and ready to stain—but that glossy sheen you see is mill glaze, a compressed surface layer formed by the heat of planing blades. If left unsanded, it prevents stain from soaking evenly, leading to blotchy color and premature peeling. The key is to remove mill glaze carefully while keeping cedar’s delicate fibers intact. Here’s how to do it right.

Why Mill Glaze Must Go

Mill glaze seals the wood surface with hardened resins and compressed cellulose. Skipping sanding means your stain will sit on top of the glaze instead of penetrating into the wood. Proper sanding opens the grain for consistent absorption and weather protection—but go too coarse, and you’ll raise fuzzy fibers that ruin the finish.

Recommended Tools

• Random-orbit or pole sander
• 9x11" silicon carbide sandpaper sheets
• Soft sanding pad or backing sponge
• Brush or vacuum for dust removal
• Moisture meter and tack cloth

Ideal Grit Sequence

• 80 grit: Break the glaze layer and open wood pores
• 120 grit: Smooth surface and remove raised fibers
• 150 grit: Final pre-stain polish for even color absorption

Step-by-Step: Cedar Siding Sanding Workflow

1. Inspect the surface. Run your hand across the boards—if they feel slick or have a waxy sheen, mill glaze is present. Test a small area with water; if it beads up, sanding is required.
2. Start with coarse removal. Use 80 Grit (25-pack) sandpaper on a random-orbit sander to lightly abrade the glaze. Keep the sander moving steadily—too much pressure can overheat and burnish the cedar.
3. Refine with mid-grit. Follow with 120 Grit (50-pack) paper to remove sanding lines and raised grain. This grit balances fiber smoothing with proper tooth for stain bonding.
4. Final polish before stain. Finish using 150 Grit (100-pack) sheets. Sand lightly along the grain until the surface feels uniformly silky but not glossy.
5. Clean thoroughly. Vacuum dust and wipe with a tack cloth. Ensure wood moisture is below 15% before applying stain or sealer.
6. Apply finish. Use a penetrating oil or semi-transparent stain formulated for softwoods to highlight cedar’s natural tone and protect against UV exposure.

Special Cases

For older cedar or weathered boards, start at 100 grit instead of 80 to preserve surface integrity. If fuzz develops, lightly resand with 180 grit or use a stiff nylon brush after drying to knock down loose fibers.

Pro Tips

• Sand only when wood is dry—moisture softens fibers and increases fuzzing.
• Use moderate pressure; let the abrasive do the work to avoid compression glazing.
• Always sand with the grain, especially on bevel-edged siding.
• Inspect under raking light—mill glaze often hides until light skims across the surface.
• Finish within 24 hours of sanding to prevent re-hardening of surface resins.

Aftercare

• Recoat every 3–5 years depending on sun exposure.
• Clean siding annually with mild detergent and soft brush.
• Spot-sand and re-stain any faded or high-wear zones to maintain even tone.

FAQs

• Can I use a belt sander? Not recommended—its aggressiveness can tear cedar fibers.
• Do I need to remove all the glaze? Yes, any unbroken glaze area will cause blotches under stain.
• What if fuzz appears? Let the surface dry and sand again lightly with 180 or 220 grit to smooth the fibers.

Watch & Learn

For softwoods like cedar, always use quality silicon carbide abrasives from the wood sanding collection. The right grit sequence—80, 120, and 150—removes mill glaze effectively while keeping the grain smooth and ready for stain.

Conclusion: Sanding cedar siding for stain success is all about control. By breaking the glaze gently, refining with mid-grits, and stopping at 150, you’ll achieve rich, even color and long-lasting finish adhesion without damaging the delicate grain.