Planer

A planer is a woodworking tool—available as a hand plane or a powered machine—used to shave thin layers from wood to smooth surfaces, reduce thickness, true edges, and fine‑tune fit; it works by moving a sharp blade across or the wood past rotating knives, producing flat, parallel faces and crisp edges for doors, shelves, trim, and furniture projects.

Planer

What is a planer?

A planer is a tool that removes thin layers of wood to create smooth, flat, and dimensionally consistent surfaces. You will see two main forms: hand planes, which you push across the wood with a sharpened iron, and powered planers, which spin knives to shave wood as the material passes by. Planers are used to adjust thickness, straighten edges, and refine parts so they fit cleanly.

How a planer works

  • Hand planes use a fixed blade set at a precise depth. You move the tool along the grain, producing thin shavings until the surface is true.
  • Electric hand planers have a rotating cutterhead and adjustable depth knob. You hold and guide the tool, similar to a hand plane but faster.
  • Thickness planers pull the board through a rotating cutterhead. The machine references the board off its bed, shaving the top face to a uniform thickness. After one face is flat from a jointer, a planer makes the opposite face parallel.

A common term you will hear is snipe. This is a slightly deeper cut at the beginning or end of a board caused by support and cutterhead dynamics. Good setup and technique can minimize it.

Types of planers

  • Hand planes
    • Block plane: Small, one‑handed plane for end grain, chamfers, and trimming.
    • Bench planes: Longer bodies for flattening and smoothing; includes jack, jointer, and smoothing planes.
    • Specialty planes: Rabbet, shoulder, and router planes for joinery adjustments.
  • Electric hand planer
    • Handheld power tool with a rotating cutterhead, great for doors, edges, and quick stock removal.
  • Benchtop thickness planer
    • Often called a lunchbox planer. Typically 12 to 13 inches wide. Good for home shops to bring rough lumber to final thickness.
  • Stationary thickness planer
    • Larger, heavier machines with wider capacity, helical cutterheads, and robust feed systems for frequent use.
  • Jointer‑planer combos
    • A single machine that can joint a face or edge and then plane to thickness by changing configurations.

Common DIY uses

  • Trimming sticking doors and easing edges after paint or swelling.
  • Taking cupped or rough boards that have been face‑jointed and bringing them to final thickness.
  • Creating parallel faces so shelves sit flat and cabinets assemble square.
  • Fine‑tuning millwork: planing an edge for a tight glue joint or consistent reveal.
  • Smoothing reclaimed lumber after checking for nails and grit.
  • Adding chamfers or bevels to furniture parts and trim.

Choosing the right planer

  • Capacity and size
    • For furniture and general DIY, a 12 or 13 inch benchtop planer covers most needs. Check maximum thickness and minimum board length ratings.
  • Cutterhead and knives
    • Straight knives are common and affordable. Helical or spiral cutterheads use small carbide inserts, reduce tear‑out in figured wood, and run quieter.
  • Depth of cut and finish
    • Look for easy depth adjustments, repeatable thickness stops, and multiple feed speeds if available. Slower feed usually gives a smoother finish.
  • Table and support
    • Long, flat infeed and outfeed support reduces snipe. On benchtop units, extension tables and a cutterhead lock help.
  • Dust collection
    • Planers make a lot of chips. A strong dust port and vac or dust collector keep the work area clear and protect the machine.
  • For hand planes
    • Choose a flat sole, quality iron (blade), and comfortable adjusters. A block plane and a No. 4 smoothing plane are great starters.
  • For electric hand planers
    • Consider width (commonly 3 to 3‑1/4 inches), depth adjustment precision, fence quality, and chip ejection direction.

How to use a planer safely and effectively

  • Inspect the wood
    • Remove nails, screws, staples, and grit. Even a small metal fragment can ruin knives.
  • Mark reference faces
    • Use a pencil grid on the surface. Passes continue until marks disappear evenly.
  • Set conservative cuts
    • Take light passes. For a thickness planer, start around 1/32 inch. For a hand plane, set a fine shaving and increase only as needed.
  • Work with the grain
    • Feed so the grain runs downhill away from the cutter to reduce tear‑out.
  • Support the board
    • Use infeed and outfeed support or roller stands. Keep boards flat on the bed and feed steadily.
  • Prevent snipe
    • Raise the trailing end slightly on entry and the leading end slightly on exit, keep pressure centered, and use a sacrificial lead and tail board in a batch.
  • Safety gear
    • Wear eye and hearing protection. Tie back hair, avoid loose clothing, and keep hands clear of the cutter.

Maintenance and care

  • Keep blades sharp
    • Dull knives cause tear‑out, burning, and chatter. Hone or replace as needed. Rotate carbide inserts on helical heads when edges dull.
  • Clean and wax tables
    • Pitch and dust increase friction and snipe. Clean with mineral spirits and apply paste wax to the bed and fences for smooth feeding.
  • Check alignment
    • Verify parallelism between the bed and cutterhead, and ensure the infeed and outfeed tables are co‑planar. Calibrate thickness scales.
  • Manage dust
    • Empty chips often and use dust collection. Clogged ports cause poor finish and overheating.
  • Inspect belts and bearings
    • On powered machines, watch for slipping belts and noisy bearings. Replace wear parts before they fail.

Mistakes to avoid

  • Trying to flatten a warped board only with a thickness planer
    • A planer makes faces parallel; it does not remove twist or cup by itself. Joint one face flat first.
  • Taking overly deep cuts
    • Deep passes strain the motor and leave a rough finish. Multiple light passes produce better results.
  • Feeding against the grain
    • This invites tear‑out, especially on figured wood. Orient boards so grain runs with the feed direction.
  • Ignoring snipe
    • Plan for it by leaving boards long and trimming ends, or batch boards with sacrificial pieces.
  • Planing stock that is too short
    • Respect the machine’s minimum length. Short pieces can kick back or snipe badly.

Related terms

  • Jointer: Flattens one face and squares an edge to that face. Use before the planer for flat reference surfaces.
  • Thickness planer: Power planer that brings a board to a precise, uniform thickness and makes faces parallel.
  • Hand plane: Manual version used for smoothing, trimming, and fine adjustments.
  • Power planer: Handheld electric planer for fast edge and surface work on site.
  • Card scraper: Steel blade used to remove fine shavings and tame tear‑out after planing.
  • Thickness sander: Sands stock to thickness with an abrasive drum; good for delicate grain where planers may tear out.

Practical examples

  • Door tune‑up: Your front door sticks after a humid spell. Remove the door, mark the rub spots, take light passes with an electric hand planer or block plane, then sand and seal the fresh edge.
  • Milling shelves: You buy rough maple boards. Joint one face and one edge, then run the board through a benchtop thickness planer to reach 3/4 inch, producing flat, parallel faces for crisp shelf fit.
  • Edge glue‑ups: Plane edges lightly to remove saw marks, check with a straightedge, and glue. The joint closes without gaps and needs minimal sanding.
  • Reclaimed lumber: After metal detection, use light passes and a slower feed speed on a thickness planer with a helical head to reduce tear‑out in mixed grain.
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