Mainspring Cleaning Lubrication and Sticking Coil Troubleshooting

American clock movements that stop after four days despite thorough cleaning reveal the frustrating problem where mainsprings with insufficient lubrication or coils catching on click rivets create intermittent binding that simple oil application cannot resolve. When clockmakers hear sudden coil release noises suggesting springs are sticking together and observe that pushing wound springs causes multiple coils to expand simultaneously, the incomplete lubrication from sponge application combined with spring loop migration toward the main wheel creates friction zones where expanding coils snag on protruding rivet heads stopping the movement. This deceptive partial failure occurs because mainsprings require comprehensive surface lubrication preventing coil-to-coil adhesion, yet casual application methods leave inner coils and critical friction surfaces inadequately protected allowing gradual binding development that manifests days into the wind cycle when spring tension and coil spacing reach critical interaction points. This guide covers complete mainspring service from cleaning to final testing addressing sticking and binding problems. You'll learn proper spring cleaning using progressive abrasives from 150-grit sandpaper through 0000 steel wool creating butter-smooth surfaces, effective lubrication application pulling spring through oiled fingers ensuring uniform coverage on both surfaces including tight inner coils, identifying and eliminating catch points including click rivet protrusions and second wheel interference, preventing spring loop migration using drilled pillar posts with twisted wire retainers, diagnosing coned springs through vertical hang tests and correcting through opposite-direction coil manipulation, and performing slow-roll power tests isolating friction locations when spring problems are eliminated but stopping persists. The key to reliable mainspring operation is understanding that springs require true smoothness achieved through proper abrasive progression and complete lubrication where every surface receives adequate oil creating uniform film preventing coil adhesion while spring positioning using loop retainers and careful rivet inspection prevents mechanical interference causing intermittent catching.

Understanding Mainspring Problems

Sticking Versus Catching

Mainspring problems fall into two categories - sticking and catching. Sticking occurs when coils adhere to each other rather than sliding smoothly. The spring sounds like multiple coils release suddenly rather than gradual unwinding. You might hear sharp snapping noise as stuck coils break free. This indicates insufficient lubrication or contaminated surfaces creating adhesion between coils.

Catching happens when the spring snags on mechanical obstructions. The expanding coils contact protruding parts blocking further movement. Common catch points include click rivets on the main wheel, bent second wheel edges, and loop ends not positioned properly. The spring may run fine for days until coil expansion reaches the catch point causing sudden stopping.

Distinguishing between these problems guides repair approach. Sticking requires cleaning and lubrication. Catching requires mechanical correction of interfering parts or spring positioning. Both problems can coexist complicating diagnosis. However, methodical testing reveals which issue dominates. Proper spring service addresses both potential problems ensuring reliable operation.

Symptoms of Inadequate Lubrication

Insufficient mainspring lubrication shows specific symptoms. The clock may run initially then stop after several days when mainspring power decreases. The reduced force can't overcome friction from poorly lubricated coils. Pushing on the spring restarts the clock by redistributing lubrication and breaking adhesion temporarily. However, the problem recurs requiring repeated intervention.

Listen carefully during spring unwinding. Properly lubricated springs make soft shuffling sounds as coils slide past each other. Dry springs create harsher scraping noises. Sudden snapping or popping indicates coils breaking free from adhesion. These audible cues reveal lubrication inadequacy before complete failure occurs.

Visual inspection after several days running shows oil distribution. Remove the movement from case and examine the spring. Properly lubricated springs show uniform sheen across visible surfaces. Dry areas appear dull or show rust bloom. Excess oil pools at spring edges or drips creating mess. The goal is complete coverage without excess - challenging to achieve with improper application methods.

Why Springs Require Special Care

Mainsprings are critical power storage components. Unlike gear train pivots requiring minimal oil, springs need substantial lubrication across entire surface area. The coils slide against each other throughout wind and unwind cycles. Any dry spots create friction multiplying across many coil interfaces. This accumulated friction dramatically reduces power delivery.

Spring steel surface finish affects lubrication retention. Rough surfaces trap old varnish and contamination. Oil can't penetrate creating proper film. The rough texture also accelerates oil breakdown. Proper surface preparation through progressive abrasive treatment creates smooth base for lubrication. Shortcuts attempting to oil rough springs waste effort producing temporary improvement at best.

American clock mainsprings are particularly demanding. Unlike European clocks with going barrels containing springs, American open springs are exposed to dust and contamination. The springs require grease or heavy oil resisting environmental degradation. Light clock oil migrates away quickly leaving springs unprotected. Using appropriate lubricants designed for mainspring service is essential for long-term reliability.

Proper Spring Cleaning Technique

Progressive Abrasive Method

Mainspring cleaning requires removing all old oil, varnish, and contamination creating perfectly smooth surface. Begin assessment by mounting spring on spring winder or quarter-inch bolt in vise. Pull out approximately ten inches examining surface condition. Light contamination responds to steel wool and mineral spirits. Heavy varnish or rust requires more aggressive treatment starting with sandpaper.

For rough springs, begin with 150-grit sandpaper. Fold small piece creating padded abrasive. Pull spring through folded sandpaper using moderate pressure. Work ten-inch sections systematically. The coarse grit removes heavy deposits quickly. Most cleaning work happens at this stage - approximately seventy-five percent of total effort. Continue until obvious roughness disappears.

Progress through finer grits - 220, then 320, then 400-grit sandpaper. Each finer grit removes scratches from previous grade creating progressively smoother surface. Use mineral spirits or light machine oil as lubricant with abrasives. The liquid prevents grit loading and reduces heat. Work each section thoroughly before advancing to next grit. Rushing produces uneven finish with remaining rough spots creating friction.

Final Polishing

After finest sandpaper, switch to steel wool for final polishing. Start with #2 steel wool removing any remaining scratches. Progress to 0000 steel wool - the finest grade - creating butter-smooth finish. The spring should feel completely smooth when you run fingers across surface. Any detectable texture indicates insufficient polishing requiring additional work.

Finish with dry cotton cloth removing steel wool residue and creating final polish. The cleaned spring should show bare metal - either bright steel or blue from tempering depending on original finish. No varnish, discoloration, or contamination should remain. Any stubborn spots that won't clean may indicate actual metal damage rather than surface contamination.

Don't polish inner five or six coils. These tight coils are difficult to access and attempting to force abrasives between them risks permanent spring deformation. The inner coils can be treated with solvent cleaning but leave mechanical polishing for accessible outer coils. Forcing abrasives into tight coils often does more harm than good.

Avoiding Common Mistakes

Never use sandpaper coarser than 150-grit for mainsprings. Aggressive abrasives like 80-grit create deep scratches difficult to remove with subsequent polishing. These scratches become stress concentrators potentially causing spring fracture under load. Start with finest grit that effectively removes contamination avoiding unnecessary material removal.

Don't completely flatten the spring during cleaning. Pulling springs perfectly straight deforms inner coils changing their natural circular shape. This deformation creates coining effect where springs no longer unwind smoothly. Pull springs with moderate tension maintaining some curvature. The goal is access for cleaning not complete flattening.

Avoid harsh chemical cleaning alone without mechanical treatment. While solvents like WD-40 or mineral spirits remove oil, they don't address surface roughness. Old varnish becomes tacky film rather than removing completely. Chemical cleaning is intermediate step but mechanical polishing creates truly smooth surfaces necessary for proper lubrication. Don't skip abrasive treatment assuming chemicals alone suffice.

Effective Lubrication Application

Lubricant Selection

Mainspring lubrication requires heavier products than standard clock oil. Light oils like Nye 140 migrate away quickly leaving springs unprotected. Medium mainspring oils like Keystone provide better retention. Synthetic gear oils like Mobil 1 75W-90 work excellently offering superior film strength and temperature stability. Heavy mainspring greases provide longest service but some clockmakers find them difficult to apply evenly.

The lubricant must coat surfaces completely without excessive thickness creating drag. Oils spread more easily than greases ensuring complete coverage. However, oils migrate over time requiring more frequent relubrication. Greases stay put providing long-term protection but need careful application preventing lumps or gaps. Choose lubricant matching your application skill and maintenance schedule.

Avoid automotive greases despite superficial similarity. These products contain additives incompatible with clock materials. The tackifiers and extreme pressure additives unnecessary for mainsprings can attack brass and create contamination. Stick with lubricants specifically designed for clock mainsprings or quality synthetic gear oils. The modest cost difference is worthwhile for proper materials.

Application Technique

Effective application ensures complete surface coverage. With spring mounted on winder, pull out approximately twelve inches. Apply lubricant stripe along spring length using dispenser bottle or directly from container. Spread lubricant with fingers coating both spring surfaces. Pull spring back and forth several times distributing oil evenly. The friction and spring warmth help spread lubricant into surface irregularities.

Continue applying and spreading for successive sections working toward spring end. Don't neglect spring ends or transitions - these areas require coverage like any other section. For tight inner coils, poke applicator tube between coils depositing lubricant. The subsequent winding action spreads this oil through inner coil interfaces.

After complete application, wind and unwind the spring several times. This working action distributes lubricant throughout spring length creating uniform film. Let the spring down in clamp or safety wire. Excess oil squeezes out from coil interfaces. Wipe away visible excess preventing dripping. However, don't remove so much that surfaces appear dry - slight sheen indicates proper coverage.

Avoiding Over and Under Lubrication

Over-lubrication wastes product and creates mess. Excess oil drips during operation contaminating movement. The heavy coating can trap dust creating abrasive paste. However, over-lubrication rarely causes operational problems beyond mess. The spring functions despite excess though appearance suffers and cleanup becomes necessary during next service.

Under-lubrication is more serious. Insufficient coverage leaves dry areas creating friction. These friction points prevent smooth unwinding. The spring sticks periodically as dry coils bind. The clock may run initially on high mainspring power but stops as tension decreases and friction becomes limiting factor. Adding lubrication requires movement disassembly making thorough initial application worthwhile.

Proper lubrication shows as uniform sheen without visible pooling. Run your finger across spring surface. It should feel slightly slippery but not soaking wet. The film protects metal without excessive thickness. If you can't see any evidence of lubrication, you've probably under-applied. If oil drips or pools visibly, you've probably over-applied. Experience develops feel for proper amount.

Eliminating Mechanical Interference

Click Rivet Problems

Click rivets hold ratchet clicks on main wheels. These rivets protrude slightly from wheel surface. If the mainspring presses against wheel, expanding coils can catch on rivet heads. This is especially common when click rivets have been replaced. Replacement rivets often protrude more than originals creating catch points that didn't exist previously.

Examine the wheel side of main wheel carefully. Locate click rivet identifying how much it protrudes. Compare to spring clearance. If the spring migrates toward wheel during unwinding, the coils eventually contact rivet creating catch point. The clock runs fine until coil expansion reaches this critical spacing then stops suddenly.

Solutions include keeping spring away from wheel through loop positioning or carefully filing rivet flush with wheel surface. Filing requires care - removing too much weakens rivet retention allowing click to loosen. Work slowly testing clearance frequently. The rivet should be flush or very slightly recessed. Any protrusion risks catching especially as springs age and clearances change.

Spring Loop Positioning

Spring loops should remain against plate away from main wheel. When loops migrate toward wheel, the expanding spring coils get squeezed into progressively smaller space. This crowding increases friction and risk of catching on interfering parts. The migration also indicates spring is moving laterally suggesting pivot problems or inadequate spring positioning.

Prevent migration by securing loop end against plate. Drill small hole through pillar post at loop location. Insert twisted wire or cotter pin at plate side of loop. This mechanical barrier prevents loop movement toward wheel. The simple modification keeps spring properly positioned throughout wind cycle eliminating migration problems.

Check loop positioning during operation. With movement running, observe spring behavior over several hours. The loop should remain stable against plate. Any movement toward wheel indicates inadequate securing or other problems requiring investigation. Don't assume initial positioning remains stable - verify through observation before declaring success.

Second Wheel Clearance

Second wheels pass under or near main wheels during rotation. If second wheel is bent or main wheel click passes too close, interference creates binding. The main wheel click travels past second wheel on every main wheel revolution. Most of the time clearance is adequate. However, if second wheel has slight bend, the interference occurs only when bent section aligns with click path.

This intermittent interference explains clocks that run several days then stop. The specific alignment creating interference takes time to occur. When it happens, the clock stops. Manual rotation changes alignment allowing clock to restart temporarily. However, continued operation eventually returns to interference position causing stopping again.

Check second wheel straightness carefully. Mount wheel on arbor between plates. Rotate slowly observing wheel edge from side view. Any wobble indicates bend. Straighten using appropriate wheel straightening techniques. Verify adequate clearance between main wheel click and second wheel edge throughout complete rotation. Adjust arbor positions within endshake limits creating maximum clearance if necessary.

Diagnosing Coned Springs

Identifying Coning

Coned springs don't lay flat when hung vertically. The coils spiral upward or downward creating cone shape rather than remaining in single plane. This misalignment creates uneven friction during unwinding. The spring binds unpredictably as misaligned coils resist smooth sliding. Coning usually results from improper spring removal or installation forcing coils out of alignment.

Test for coning by hanging spring vertically from loop end. Properly aligned springs hang in relatively flat plane with coils stacked vertically. Coned springs show obvious spiral - coils ascending or descending from central axis. Even modest coning creates operational problems. The spring may seem fine during initial examination but coning becomes apparent when hung freely.

Severe coning is immediately obvious. The spring leans dramatically to one side under its own weight. Moderate coning shows as gradual spiral requiring careful observation. Slight coning may not cause problems in all movements but correction improves reliability. Any visible coning warrants correction before installation especially if spring sticking or binding occurs.

Correction Technique

Correct coning by pulling inner coils in direction opposite the cone. If spring cones upward, pull inner coils downward. If spring cones downward, pull inner coils upward. Work gently using hands or appropriate tools. The goal is realigning coils into flat plane not creating opposite cone through overcorrection.

Test frequently during correction. Hang spring checking alignment. Make small adjustments rather than dramatic pulls. The spring steel resists deformation but excessive force creates new problems. Patient gradual correction produces best results. Expect to make multiple small adjustments working toward proper alignment.

After correction, hang spring verifying coils remain in plane. The spring should hang straight without spiraling. Minor variations are acceptable but obvious coning requires additional correction. When satisfied with alignment, mark spring orientation before installation. This prevents accidental reinstallation in wrong direction undoing correction work.

Prevention During Service

Prevent coning by careful spring handling during service. When removing springs, let them down slowly using proper spring winders. Don't allow springs to escape suddenly. The violent expansion can permanently deform coils creating coning. Similarly, install springs carefully controlling expansion preventing asymmetric loading creating misalignment.

During cleaning, avoid completely flattening springs. Pulling springs perfectly straight on winders can deform inner coils. Maintain some curvature during cleaning operations. The moderate tension provides access without excessive deformation. Remember the spring's natural state is coiled not flat - respect this geometry during handling.

When installing springs, wind them into position evenly. Don't force springs creating localized bending. If spring won't fit easily, examine for obstruction rather than forcing installation. Proper technique maintains spring geometry throughout service preventing coning and other deformation problems.

Advanced Troubleshooting

Slow Roll Testing

When mainspring service doesn't resolve stopping problems, slow roll testing identifies friction elsewhere in train. Remove pallet arbor allowing escape wheel to spin freely. Let mainspring down completely. Wind just one or two clicks until wheels begin rotating. Observe how wheels coast to stop noting any irregularities in motion.

Mark each wheel with felt pen. Wind again observing where wheels stop. Repeat several times. If any wheel consistently stops at same position, that location has binding problem. The consistent stopping indicates tight spot in that wheel's rotation cycle. Investigate pivot condition, bushing alignment, and gear meshing at that wheel.

Perform test with movement in multiple positions - normal running position, face up, and face down. Gravity affects friction differently in each orientation. Problems that don't show in one position may be obvious in another. Compare running times and behaviors identifying position-dependent issues suggesting bent pivots or inadequate endshake.

Power Assessment

If test requires more than two mainspring clicks to start wheels rotating, inadequate power reaches escape wheel. This indicates friction in train or weak mainspring. Distinguish between these causes through systematic testing. A healthy movement should begin rolling with minimal mainspring tension. Excessive clicks needed suggests significant friction requiring correction.

Observe deceleration rate. Wheels should slow gradually like car coasting to stop. Rapid stopping like braking suggests tight components. Jerky motion or hesitation indicates intermittent binding. These observations guide investigation toward specific problem areas. Smooth gradual deceleration with random stopping positions indicates healthy train.

Test train components individually. Remove wheels one at a time testing remaining train. If removing specific wheel dramatically improves behavior, that wheel or its associated pivots have problems. This isolation technique identifies problem components when overall behavior indicates friction without obvious specific cause.

Bushing Related Issues

Improperly installed bushings create friction mimicking mainspring problems. Bushings off-center from original pivot holes change gear depthing. The teeth mesh too deep or too shallow creating friction. This is particularly problematic in movements with lantern pinions where proper depthing is critical for smooth operation.

Verify bushing installation using depthing references. Compare pinion engagement depth to properly operating movements. The pinion leaves should engage wheel teeth substantially but not so deep that pinion shaft touches wheel teeth. Improper depth appears as excessive or insufficient tooth engagement creating friction or weak power transfer.

Test for binding by rotating paired wheels together. They should spin smoothly without resistance. Any roughness indicates depthing problems requiring bushing reinstallation or repositioning. Don't assume bushing tools alone ensure proper positioning. Visual verification and operational testing confirm correct installation preventing friction problems mimicking mainspring issues.

FAQs

How much mainspring lubricant should I apply?

Apply sufficient lubricant creating uniform sheen across spring surfaces without visible pooling or dripping. Pull spring through oiled fingers or apply stripes along spring length then spread evenly on both surfaces using fingers. After complete application, wind and unwind spring several times distributing lubricant throughout. Let down spring allowing excess to squeeze out from coil interfaces. Wipe visible excess but leave slight sheen indicating proper coverage. Properly lubricated springs feel slightly slippery when you run fingers across surface but don't appear soaking wet. Five drops of medium mainspring oil like Keystone typically suffices for standard American clock mainsprings though application technique matters more than precise quantity. Synthetic gear oils like Mobil 1 75W-90 or clock mainspring greases work excellently providing superior retention and protection. Under-lubrication causes friction and sticking while over-lubrication creates mess but rarely prevents operation. Err toward adequate coverage ensuring complete protection rather than minimal application risking dry spots.

Why does pushing on my mainspring make the clock start running again?

Pushing on mainsprings restarts stopped clocks by breaking coil adhesion from inadequate lubrication or relieving catch points where coils snag on click rivets or other obstructions. When coils stick together from insufficient lubrication, manual pressure redistributes oil and separates adhered surfaces temporarily restoring operation. However, the problem recurs as coils expand during unwinding eventually sticking again. When springs catch on mechanical obstructions like protruding click rivets, pushing shifts spring position clearing the interference point. The clock runs until coil expansion returns to catch point causing stopping again. Both problems indicate incomplete mainspring service. Proper cleaning creating smooth surfaces, thorough lubrication ensuring complete coverage, and eliminating mechanical interference through rivet filing and loop positioning prevent these intermittent stopping problems. Clocks requiring repeated manual intervention haven't received adequate mainspring service. Complete disassembly, proper cleaning with progressive abrasives, effective lubrication application, and mechanical interference correction create reliable sustained operation without manual assistance.

What causes mainsprings to cone and how do I fix it?

Mainspring coning occurs when coils spiral upward or downward rather than remaining in single flat plane typically caused by improper handling during removal or installation. Violent spring escape during let-down, excessive flattening during cleaning, or forcing springs into position creates asymmetric stress permanently deforming coils. Test for coning by hanging spring vertically from loop end - properly aligned springs hang flat while coned springs show obvious spiral ascending or descending from central axis. Correct coning by gently pulling inner coils in direction opposite the cone while repeatedly testing alignment. If spring cones upward, pull inner coils downward making small gradual adjustments. Hang spring frequently verifying improvement without creating opposite cone through overcorrection. Prevention requires careful spring handling using proper winders controlling expansion, maintaining some curvature during cleaning operations avoiding complete flattening, and installing springs evenly without forcing. Even slight coning creates friction during unwinding as misaligned coils resist smooth sliding causing intermittent binding and stopping problems.

Should I use sandpaper or steel wool for cleaning mainsprings?

Use progressive abrasive sequence starting with appropriate sandpaper grit then finishing with steel wool creating butter-smooth surface. Begin with 150-grit sandpaper only if spring shows heavy varnish, rust, or significant roughness. Most springs start with 220 or 320-grit removing moderate contamination. Work through progressively finer grits - 220, 320, 400 - each grade removing scratches from previous abrasive. Never use sandpaper coarser than 150-grit as aggressive abrasives create deep scratches that become stress concentrators. After finest sandpaper, switch to #2 steel wool followed by 0000 steel wool - finest grade - creating final polish. Finish with dry cotton cloth removing residue. The cleaned spring should feel completely smooth when running fingers across surface with no detectable texture. Steel wool alone suffices for springs with light contamination or varnish film but moderate to heavy deposits require sandpaper beginning proper abrasive progression. Use mineral spirits or light machine oil as lubricant with all abrasives preventing grit loading and reducing heat. Don't skip steps attempting shortcuts - each finer grade is necessary removing previous scratches creating smooth base for effective lubrication.

How do I prevent mainspring loop migration toward the main wheel?

Prevent mainspring loop migration by drilling small hole through pillar post at loop location and inserting twisted wire or cotter pin at plate side of loop creating mechanical barrier. The spring loop should remain against plate away from main wheel throughout wind cycle. When loops migrate toward wheel, expanding coils get squeezed into progressively smaller space increasing friction and risk of catching on click rivets or other protruding parts. Position drill hole so inserted wire or pin contacts loop edge nearest wheel preventing movement in that direction while allowing normal spring expansion. Use wire diameter that fits hole snugly without excessive protrusion beyond pillar post. Twist wire ends or bend cotter pin securing in place. This simple modification keeps spring properly positioned eliminating migration problems that cause intermittent catching and friction. Check positioning during operation observing spring behavior over several hours verifying loop remains stable. Initial positioning may appear adequate but operational forces can cause gradual migration requiring mechanical retention. Don't assume springs naturally stay in place - secure them preventing problems.

What is slow roll testing and when should I use it?

Slow roll testing identifies friction locations in gear trains by removing pallet arbor allowing escape wheel to spin freely then winding mainspring just one or two clicks observing how wheels coast to stop. Healthy movements begin rolling with minimal tension. If test requires more than two clicks indicating inadequate power reaches escape wheel from excessive friction. Mark each wheel with felt pen. Wind again repeatedly observing where wheels stop. Consistent stopping at same position indicates binding problem at that wheel requiring investigation of pivot condition, bushing alignment, and gear meshing. Perform test in multiple positions - normal running, face up, face down - as gravity affects friction differently revealing position-dependent issues suggesting bent pivots or inadequate endshake. Use slow roll testing when mainspring service doesn't resolve stopping problems eliminating spring as cause. The test isolates friction elsewhere in train guiding investigation toward specific problem areas. Smooth gradual deceleration with random stopping positions indicates healthy train while rapid stopping, jerky motion, or hesitation reveals tight components requiring correction. This systematic diagnostic approach prevents shotgun repairs addressing symptoms rather than causes.

Can I clean mainsprings without a spring winder?

Yes, mainsprings can be cleaned without dedicated spring winders though winders provide safer controlled working conditions. Alternative method uses quarter-inch bolt or large nail mounted in vise as spring holder. Hook spring loop over bolt. Pull spring outward using moderate tension exposing ten-inch sections for cleaning. Work through progressive abrasive sequence treating exposed sections then pulling additional length continuing around entire spring. The challenge without winder is maintaining control during cleaning and reinstallation. Springs have significant stored energy even when partially extended. Loss of control allows sudden contraction potentially causing injury. Use safety wire or clamps securing partially extended springs preventing uncontrolled release. Reinstallation without winder requires careful manual coiling maintaining spring alignment preventing coning. Insert spring end into position then carefully wrap subsequent coils keeping them aligned in single plane. This manual installation is possible but tedious requiring patience and care. Spring winders cost modest amounts providing safety and convenience justifying investment for regular clock service work. However, occasional service can be accomplished safely using improvised holders with proper caution and technique.