Detailed Description of Pegging Clock Pivots

(dataclaude.ai)

Detailed Description of Pegging Clock Pivots

Pegging is one of the most important steps in clock repair—it removes old oil, dirt, and debris from the pivot holes (bushings) in the clock plates. This process is essential even when using ultrasonic cleaners, as dried crud often remains in the holes after chemical cleaning.

What is Pegging?

Pegging uses pointed wooden sticks (called pegwood or pegs) to mechanically clean the inside of pivot holes. The wood fibers absorb old oil and lift out debris that chemical cleaning can't fully remove.

When to Peg

Getting holes clean is a painstaking process that requires a full disassembly, cleaning, pegging with peg wood or toothpick, smooth broaching and pegging again. Most I've talked with still advise pegging—even with ultrasonic cleaning.

Pegging is good practice, as others do this. A cleaning that includes pegging all the pivot holes is important, as stubborn dried gunk in the holes can cause later problems if not removed.

Materials Needed

Pegwood Options:

• Traditional pegwood (orangewood or pearwood from horological supply houses)
• Cracker barrel round toothpicks will handle most bushings
• Good quality hardwood toothpicks, cleaning them out from both sides of the plate
• For bigger bushings, use a wooden skewer
• Bamboo skewers
• Shish kabob skewers

Additional Supplies:

• Cleaning solvent (mineral spirits, acetone, or proper clock cleaning solution)
• Magnifying glass or loupe
• Good lighting
• Clean workspace

Step-by-Step Pegging Process

1. Disassemble the Movement Completely You cannot properly peg pivot holes on an assembled movement. Each plate must be accessible from both sides.

2. Pre-Clean the Movement Pre-wash all movement parts with Dawn detergent and warm water, including pegging out pivot holes, wiping off pivots and gears. This removes surface dirt before the main cleaning.

3. Chemical Cleaning (Optional but Recommended) Use ultrasonic cleaning or hand-clean with mineral spirits/proper clock cleaning solution to remove the bulk of old oil and dirt.

4. Sharpen Your Pegwood Use a sheet of 80 grit sandpaper to clean and sharpen as needed. The peg should have a tapered point that fits snugly in the hole without being forced.

5. Apply Solvent to the Peg Peg out each pivot hole with solvent, until the peg comes out clean. You can carefully peg the holes, using a speck of acetone on the tip of a bamboo peg/skewer. In and out quickly and you won't make a mess.

6. Insert the Peg into the Hole

• Insert the pointed peg into the pivot hole from one side
• Rotate the peg gently while applying slight pressure
• The wood fibers will absorb old oil and lift debris
• Clean them out from both sides of the plate

7. Repeat Until Clean Peg the holes until the pegs come out clean. Change them frequently when they appear dirty. This is critical—one pass is never enough.

Important Note: I thought that just pegging was enough until one day I pegged after smooth broaching and the peg came out with black residue on it. This demonstrates why multiple passes are essential.

8. Inspect Your Work Examine each hole under magnification. The hole should be clean and free of any dark deposits or oil residue.

Power Pegging Technique (Advanced)

Some repairers use power tools to speed up the process:

With a flex shaft and collets, you can peg a pivot hole in seconds using one bamboo skewer. Chuck them up in a Foredom tool. Someone suggested chucking up a toothpick on a cordless drill to clean bushings.

Power Pegging Advantages:

• Much faster than hand pegging
• Consistent rotation ensures thorough cleaning
• Can use light polishing compounds if desired

Caution with Power Pegging:

• Don't apply excessive pressure
• Keep the peg moving to avoid heat buildup
• Be careful not to enlarge the hole

Using Polishing Compounds (Optional)

If one wants to use an abrasive or polish, there's Feldspar (Bon Ami), toothpaste or something like Simichrome polish. Any of those can be easily removed from the brass if used sparingly with a light touch.

Both feldspar and chalk are rapidly broken down, and are too soft to abrade steel if any abrasive might remain in the bearing. Caution: do not use rouge or any polish hard enough to polish steel.

Critical Warning: Any polish one might choose to use should be used after regular pegging and its complete removal is essential. Clean the plates again in a second ultrasonic bath after using any polish.

Proper Sequence with Other Operations

Here's what must happen (assuming the hole does not require re-bushing):

1. Use pegwood inserted into the hole to loosen and clean out old dirt, oil, debris, etc.
2. Clean the hole using detergent and brush or via ultrasonic
3. Burnish the hole with appropriate size burnishing tool

However, there's debate about order. Some save the pegging for the last step, after the crud has been washed out, loosened up.

Always use oil on the round broach and go back with your wood pegging after doing the round broaching. This ensures any debris created by broaching is removed.

Common Mistakes to Avoid

1. Not pegging enough times - Keep going until pegs come out perfectly clean
2. Using dirty pegs - Change pegwood frequently
3. Forcing oversized pegs - This can enlarge the hole
4. Skipping holes - Every pivot hole must be pegged, no exceptions
5. Not cleaning from both sides - Work from front and back of each plate
6. Stopping after ultrasonic cleaning - Ultrasonic cleaning does not do the job where it counts, on the jewels

Why Pegging is Essential

Even after thorough ultrasonic cleaning, old congealed oil and oxidation can remain in pivot holes. The only thing that will remove the dried up oil and oxidation around the holes is mechanical cleaning. This residue creates friction that can stop a clock or cause excessive wear.

The pivot wears in a straight line, and creates a little tunnel for itself. Eventually the increased friction is too much for the clock to overcome and it stops. Proper pegging removes this contamination and helps prevent premature wear.

Final Cleaning

I have found that a thorough cleaning is needed after any pivot polishing or burnishing. After all pegging is complete, many professionals recommend a final rinse and dry to ensure no wood fibers or debris remain in the movement.

After the second bath, handle the brass plates and wheels while wearing latex or nitrile gloves to prevent fingerprint corrosion.

Conclusion

Pegging is a simple but essential skill that separates thorough clock repair from superficial cleaning. While it's tedious work, the time invested in properly pegging every pivot hole pays dividends in longer clock life and reliable timekeeping. Master clockmakers consider it an indispensable part of any complete overhaul.