What Actually Causes Tearout in Figured Wood

A woodworker planes curly maple. The first pass goes smoothly across 8 inches of board. The surface gleams. Then the plane hits a figured section. The blade catches, chatters, and rips fibers out of the wood. Where there was smoothness, now there are craters and torn grain.

The blade didn't dull. The technique didn't change. The wood changed. Grain direction reversed. What worked perfectly on straight grain fails catastrophically when grain switches direction every half-inch.

Grain Reversal Mechanics

Wood fibers grow in directions determined by tree growth patterns. Straight-grained wood has fibers running parallel to the trunk. Figured wood has fibers that change direction - diving into the board, emerging, diving again. These reversals create the visual patterns people call figure.

Curly maple shows this clearly. The fibers undulate like waves. In one spot, fibers angle upward toward the surface at 20 degrees. An inch away, they angle downward into the board at 20 degrees. The reversal happens over short distances - sometimes as little as 1/4 inch.

When a cutting edge approaches wood with the grain (fibers angling away from the cut), it slices cleanly. The edge separates fibers with minimal force. Torn grain is rare. When that same edge approaches wood against the grain (fibers angling toward the cut), it tries to lift fibers before cutting them. Tearout happens.

Figured wood presents both grain orientations simultaneously. One area cuts cleanly. The adjacent figured area tears out. No single cutting direction works for the entire board. Every pass produces some tearout somewhere.

The severity depends on figure tightness and fiber angle. Gentle wavy grain with 10-degree fiber deviation tears out minimally. Tight curl with 30-degree fiber angles tears out dramatically. Quilted figure with multiple directions in close proximity tears out worst of all.

Bird's-eye maple demonstrates extreme localized grain disruption. Each "eye" is a tiny whorl of grain surrounding a bud formation. The grain spirals around these spots in all directions. A cutting edge encounters grain running every direction within a quarter-inch area. Clean cutting becomes nearly impossible.

Cutting Angle Physics

A cutting edge approaching wood at different angles produces different results. Low cutting angles (30-40 degrees from horizontal) slice fibers with minimal compression. High cutting angles (55-65 degrees) compress fibers before cutting. The compression changes how tearout develops.

Low-angle cutting on straight grain with favorable direction produces the cleanest cuts. The edge enters wood at a shallow angle, slicing fibers cleanly. Shavings form smoothly. The cut surface shines. This works only when grain direction cooperates.

Low-angle cutting against the grain lifts fibers before severing them. The shallow approach angle gets under fiber ends. As the blade advances, it levers fibers upward. The fibers break above the cut line rather than at it. Tearout develops as lifted fibers tear free.

High-angle cutting approaches wood more vertically. The steeper angle compresses fibers ahead of the cut. This compression prevents lifting. Fibers get crushed and sheared rather than levered. Against-the-grain cutting produces less tearout at high angles because compression prevents lifting.

The tradeoff is cutting effort. High-angle cutting requires more force. The compression and shearing take more energy than low-angle slicing. Hand plane use becomes noticeably harder. Power tool motors work harder. Feed rates drop.

Some figured woods respond better to high angles. Others still tear out. The fiber structure and figure type determine whether high-angle cutting eliminates tearout or just reduces it. No single angle solves all figure problems.

Blade Sharpness Effects

Dull blades crush fibers before cutting them. Sharp blades slice fibers cleanly. The difference becomes critical in figured wood. A blade that cuts straight grain acceptably while slightly dull tears figured wood catastrophically.

Sharpness affects how fibers separate. A truly sharp edge (0.001-0.002 inch radius) parts fibers with minimal side force. Fibers separate cleanly at the cut line. A dull edge (0.005-0.010 inch radius) pushes fibers sideways before cutting. This sideways force tears fibers instead of cutting them.

Figured wood with reversing grain magnifies dullness effects. Against-the-grain sections get torn by even slight dullness. The blade catches on fiber ends, levers them up, and tears them out. Sharp blades still tear figured wood when grain reverses, but less severely than dull blades.

Micro-chipping of cutting edges happens during use. Carbide router bits and plane irons develop tiny chips in the cutting edge from hitting hard spots or abrasive inclusions. These chips act as dull spots. Figured wood tearout concentrates at chip locations.

Honing frequency matters more with figured wood than straight grain. A blade that stays sharp for 100 feet of straight-grain planing might need sharpening after 20 feet of figured wood. The reversing grain stresses the edge more. Dulling happens faster. Tearout increases correspondingly.

Chipbreaker Function

Chipbreakers (also called cap irons) bend shavings upward as they form. This bending breaks shavings into short segments. The breaking action also pressures wood ahead of the cut, compressing fibers and preventing lifting.

Chipbreaker distance from the cutting edge determines effectiveness. A chipbreaker set 1/16 inch back provides minimal compression. Shavings form and lift before reaching the breaker. Tearout develops normally. A chipbreaker set 1/64 inch back provides strong compression. Shavings curl immediately. Fiber lifting is suppressed.

Close chipbreaker settings (under 0.020 inch) dramatically reduce figured wood tearout. The intense compression ahead of the cut prevents fibers from lifting even when grain reverses. Research by Kato and Kawai showed chipbreakers are more effective than cutting angle changes for figured wood.

The tradeoff is mouth clogging. Close chipbreaker settings produce tightly-curled shavings that jam more easily. Hand planes with close breaker settings clog after shorter cutting distances. Clearing jams becomes frequent. The reduced tearout comes at the cost of increased maintenance.

Chipbreaker position also affects cutting force. Close settings increase resistance. The plane becomes harder to push. Power tools draw more current. Feed rates drop. The compression that prevents tearout also increases cutting resistance.

Depth of Cut Relationships

Thin shavings tear out less than thick shavings in figured wood. A 0.001-inch cut might leave the surface smooth. A 0.010-inch cut tears fibers out. The thicker cut lifts fibers further before severing them. Deeper lifting creates worse tearout.

Multiple light passes work better than single heavy passes on figured wood. Three passes at 0.003 inches each produce less total tearout than one pass at 0.009 inches. The cumulative result is smoother despite more total cutting time.

The relationship isn't linear. Doubling cut depth more than doubles tearout severity. A 0.005-inch cut might produce minor tearout. A 0.010-inch cut produces major tearout. The exponential relationship means the last few thousandths of thickness removal cause the most problems.

This explains why final smoothing operations use extremely light cuts. A smoothing plane set for 0.001-inch shavings produces acceptable results on figured wood that tears out at 0.005-inch depth. The ultra-light cut minimizes fiber lifting regardless of grain direction.

Power tools show similar depth effects. A planer taking 1/32-inch cuts tears figured wood badly. The same planer taking 1/64-inch cuts produces better results. Many figured boards get planed in stages - heavier cuts initially, progressively lighter cuts for final thickness.

Feed Rate Interactions

Fast feed rates give fibers less time to lift before severing. Slow feed rates allow more lifting and tearing. The relationship varies with tool type and configuration. Hand planes controlled manually show different patterns than power planers with fixed feed speeds.

Hand plane feed rate changes subtly affect tearout. Slow, deliberate pushing allows the blade time to lever fibers up before cutting them. Quick, confident pushing cuts fibers before significant lifting develops. The speed difference is modest - perhaps 2× - but the tearout difference is noticeable.

Power planer feed rates interact with cutter head speed. A planer with 8,000 RPM cutter head and 20 feet-per-minute feed rate takes 0.030-inch cuts between knife contacts. Doubling feed rate to 40 FPM increases cut-per-knife to 0.060 inches. Tearout increases correspondingly.

Router feed rate effects are more dramatic. Slow feeds allow router bits to rub and burn wood. Fast feeds can overload bits and cause grabbing. An intermediate feed rate exists where tearout is minimized. Finding this rate requires experimentation for each wood and figure pattern.

The optimal feed rate for figured wood differs from the optimal rate for straight grain. Figured wood generally needs slower feeds to minimize tearout. The slower feed allows more careful fiber severing. The tradeoff is longer machining time and potentially more heat buildup.

Grain Reading Limitations

Reading grain direction on figured wood involves looking at end grain patterns and face grain appearance. Fibers angling one direction create specific visual patterns. These patterns indicate grain direction - supposedly.

Figured wood defeats simple grain reading. The grain changes direction every few inches or even every few fractions of an inch. What looks like grain running left might reverse to running right an inch away. The visual cues that work for straight grain become unreliable.

Some figure types are completely unreadable. Quilted maple shows grain running multiple directions simultaneously in small areas. Bird's-eye maple has grain spiraling around eyes with no consistent direction. Crotch figure from branch junctions has grain flowing in three dimensions.

Attempted grain reading on these woods produces wrong predictions. The woodworker feeds the board through thinking they've read the grain correctly. Tearout happens anyway. The figuring pattern overrides the apparent grain direction. No reading method succeeds reliably.

This unpredictability forces different approaches. Rather than trying to work with grain direction, techniques that work regardless of grain direction become necessary. High cutting angles, close chipbreakers, and light cuts work independent of grain reading.

Scraping vs Cutting

Scrapers remove wood by abrading rather than cutting. A card scraper or scraper plane held at 90 degrees to the surface doesn't lift fibers - it scrapes them off. The grain direction becomes irrelevant. Tearout essentially disappears.

The scraping action happens through a burr on the scraper edge. This burr, formed by burnishing, creates a tiny hook that pulls fibers free. The pulling happens at such a small scale that fiber lifting doesn't occur. Even reversing grain gets scraped cleanly.

Scraping removes material slowly compared to planing. A sharp plane can remove 0.005-0.010 inches per pass. A scraper removes 0.0005-0.001 inches per pass. Ten times as many passes are required. The slow rate trades efficiency for tearout elimination.

Scrapers work well for final surface preparation on figured wood. The wood gets planed close to final thickness accepting some tearout. Scrapers then remove the tearout plus final thickness. The two-stage process - plane roughly, scrape finally - handles figured wood more efficiently than trying to plane perfectly.

Scraper planes like the Stanley #80 or #112 provide better control than card scrapers. The blade angle and pressure stay consistent. Flat surfaces result more easily. Card scrapers flex and dig, creating undulations. Both work, but planes provide better flatness.

Sanding Approach Effects

Sanding removes wood through abrasion. Grain direction doesn't matter. Sanding works on any grain orientation. This makes sanding the ultimate solution for figured wood surface preparation - at the cost of dust, time, and loss of crispness.

Progression through grits matters. Starting with 80-grit on figured wood removes material quickly but creates deep scratches. These scratches show as darker lines in finished wood. Starting with 120-grit removes material slower but creates finer scratches that finish better.

Belt sanders remove stock quickly but are difficult to keep flat. Orbital sanders remove stock slowly but maintain flatness better. The choice depends on whether stock removal or flatness is the priority. Figured wood already has tearout divots. Flatness usually needs restoration.

Sanding reverses the normal woodworking sequence. Normally, machining happens until surfaces are smooth, then finishing begins. With figured wood, machining creates tearout, then sanding removes both tearout and machine marks. The sanding becomes the real surface preparation, not just finish prep.

The dust generation from sanding figured wood to smooth surface exceeds straight-grain sanding by 2-3×. More stock removal is required to eliminate deeper tearout. Dust collection becomes more critical. Respiratory protection matters more. The convenience of grain-independent surface preparation comes with these burdens.

Power Planer Cutter Configuration

Straight-knife planer heads present multiple knives to wood simultaneously. Each knife takes a cut. If knives are aligned perfectly parallel, each cut happens at the same depth. Misalignment causes one knife to cut deeper than others. That knife creates most tearout.

Helical or spiral cutter heads present knife edges at angles to the feed direction. Each small carbide insert contacts wood at a slight skew. This skewed approach reduces tearout compared to straight knives. The improvement is dramatic with figured wood.

The skewed cut happens because each insert enters wood at an angle rather than straight across. This creates a slicing action similar to how skewing a hand plane reduces tearout. The continuous skew angle across the cutter width means some portion always cuts favorably even when grain reverses.

Carbide insert size affects results. Smaller inserts (1/4 inch square) create smoother surfaces than larger inserts (5/8 inch square). The smaller inserts mean more individual cuts per inch of feed. More cuts mean smaller tearout spots. The surface appears smoother.

Cutter head speed affects tearout independently of feed rate. Faster rotation increases cuts per inch at any feed rate. A 4,000 RPM head creates more cuts per inch than a 2,000 RPM head at the same feed speed. More cuts mean shallower cut per knife, reducing tearout.

Moisture Content Effects

Wood moisture content affects machining behavior. Dry wood (6-8% MC) machines differently than damp wood (10-14% MC). The moisture softens fibers. Softer fibers tear more easily. This affects figured wood dramatically.

Kiln-dried lumber at 6-7% MC exhibits the least tearout. The dry, stiff fibers resist lifting. They cut more cleanly even when grain reverses. The same wood at 12% MC shows more tearout. The fiber softness increases lifting tendency.

Air-dried lumber typically reaches 10-12% MC depending on climate. This moisture content is workable but not optimal for figured wood machining. Bringing air-dried figured lumber into a dry shop (30-40% RH) for weeks before machining lets it dry to 7-8% MC. Tearout reduces noticeably.

Freshly planed wood shows less tearout than wood planed then stored. The planing process compresses surface fibers. This compression stays for hours. If the board gets stored between roughing and finishing passes, the compressed fibers relax. Subsequent finishing passes encounter relaxed fibers that tear more easily.

Tool Type Selection

Different cutting tools produce different tearout patterns on figured wood. Hand planes with close chipbreakers produce the least tearout. Power planers with helical heads come second. Straight-knife planers produce the most tearout.

Routers with spiral bits reduce tearout compared to straight bits. The spiral geometry creates a slicing action similar to helical planer heads. Down-spiral bits compress fibers into the cut. Up-spiral bits can lift fibers. Down-spiral works better for figured wood.

Jointers with long beds and slow feed rates produce acceptable results on figured wood when knives are sharp and cuts are light. Short-bed jointers with quick feeding tear figured wood badly. The rapid fiber engagement doesn't allow compression time.

Combination scenarios work effectively. Rough dimension with power tools accepting tearout. Finish with hand tools using appropriate techniques. The power tools remove most material quickly. Hand tools handle the figured sections carefully. Time investment goes into final passes where it matters most.

Species Variation

Some species show figure frequently. Maple, ash, and some mahoganies exhibit figure in 10-20% of boards. These figured boards command premium prices. The figure comes with tearout challenges. Other species like cherry or walnut show figure rarely. Figured examples are especially valuable and challenging.

Figure types vary by species. Maple shows curly figure, quilted figure, and bird's-eye. Each type tears out differently. Curly maple shows predictable if problematic tearout. Quilted maple tears out worse. Bird's-eye is nearly impossible to machine without some tearout.

Mahogany shows ribbon figure, crotch figure, and pommele. Ribbon figure machines reasonably well with proper technique. Crotch figure tears out spectacularly. Pommele falls between these extremes. The same species presents different challenges depending on figure type.

Tropical species often show interlocked grain - a form of figure where grain spirals around the trunk in alternating directions. This produces bands of alternating grain direction. Every few inches, grain direction reverses 180 degrees. Tearout happens in bands corresponding to grain reversal.

Softwoods rarely show figure. When they do, the softer fiber structure tears out more easily than hardwoods. Figured pine or fir presents extreme tearout challenges. The combination of reversing grain and soft fibers makes clean machining nearly impossible without sanding.

What Actually Works

Figured wood tearout reduces through multiple approaches used together. No single technique eliminates it completely. Combinations of sharp blades, light cuts, appropriate cutting angles, and close chipbreakers minimize tearout to acceptable levels.

The sequence matters. Initial dimensioning with power tools removes bulk material accepting some tearout. Subsequent passes with progressively lighter cuts reduce tearout depth. Final passes with hand tools or scrapers eliminate remaining tearout. The staged approach recognizes that perfect first-pass machining isn't achievable.

Accepting tearout on initial passes saves time. Trying to achieve tearout-free surfaces with heavy stock removal fails. The depth-of-cut and tearout relationship makes heavy cuts inherently tearout-prone. Light final cuts remove tearout created by heavy initial cuts.

Grain direction reading works for planning tool path but doesn't eliminate tearout. Knowing grain direction lets the woodworker anticipate problem areas and employ appropriate techniques there. The knowledge helps but doesn't solve the fundamental problem of reversing grain.

The reality is that some figured wood tears out regardless of technique. Extreme figure, tight reversals, or particularly soft fiber structure defeats even expert technique. Sanding becomes the only practical finishing method. The figure that makes the wood valuable also makes it difficult to work.