1. Preparatory Work Before Hole Cleaning
Cut off the surrounding welding residues and large slag agglomerates on the table surface first with a plastic scraper to avoid dragging hard welding debris deeper into positioning holes during cleaning. Prepare dedicated cleaning tools: hole wire brushes matching Φ28 mm / Φ16 mm holes, compressed air blow guns, thread tap cleaners, anti-rust degreaser, soft cotton rags and thin anti-rust lubricant. Stop welding operations around the blocked area to prevent new molten slag from filling the holes during maintenance.
2. Basic Cleaning for Holes Blocked by Loose Iron Filings and Light Welding Spatter
Insert the matched cylindrical wire brush into the blocked hole and rotate back and forth repeatedly to scrape loose metal scraps and thin slag attached to hole walls and internal threads.
Aim a high-pressure dry compressed air gun straight into the hole to blow out all powdered metal debris swept down by the brush. Tilt the workbench slightly if possible to let residues fall out by gravity.
Dip a cotton strip into neutral degreasing fluid, feed it into the hole to wipe off oil stains mixed with tiny metal particles, then blow dry thoroughly with air flow to eliminate residual moisture.
3. Deep Cleaning for Holes Clogged with Hard Solid Welding Slag
Spray low-corrosion slag dissolving cleaning agent into the blocked hole and leave it to soak for 5–10 minutes to soften the cured welding slag and carbonized deposits. Avoid strong acid cleaners which will corrode the nitrided wear-resistant layer and internal threads.
Use a thread cleaning tap with smooth tooth profile to slowly twist into the hole, breaking apart hardened slag without damaging the standard M16 internal thread; do not apply violent force to prevent thread stripping.
Alternate wire brushing and air blowing multiple times until no solid particles eject from the hole opening. Inspect the hole interior with a flashlight to confirm full clearance of blockages.
4. Treatment of Holes Stuck with Oxidation Rust and Corrosion Deposits
For holes blocked by rust scale, pour diluted rust remover into the cavity and soak for 15 minutes to dissolve rust accumulations on hole walls and threads.
Polish inner walls gently with a fine metal wire brush, then blow away rust powder completely with compressed air. Wipe the hole dry with oil-absorbent cloth to eliminate residual liquid that causes secondary rust.
After cleaning, add a thin layer of anti-rust lubricant to the hole interior to form a protective film against oxidation and slag adhesion in subsequent welding processes.
5. Post-Cleaning Inspection and Preventive Operations
Insert a standard positioning pin into the cleaned hole; the pin should slide in smoothly without jamming or obvious resistance, proving the hole and threads are fully unobstructed. If the pin sticks partially, repeat the deep cleaning process.
Wipe excess lubricant on the tabletop around the hole to reduce adhesion of new welding spatter.
Form a daily cleaning routine: brush all positioning holes and blow away residues after each shift to avoid accumulated slag causing severe blockages that require deep chemical cleaning.
6. For Severely Damaged Holes with Permanent Slag Bonding
If welding slag has melted and fused tightly with hole metal and cannot be cleared by chemical soaking and brushing, use a precision reamer to lightly trim the hole inner wall to remove fused slag, then re-tap the internal thread to restore standard assembly tolerance. Avoid over-reaming which enlarges the hole and reduces positioning accuracy.
Reference
GB/T 7714 Format
Ren B. Blockage cleaning technology and thread protection of positioning holes on 3D flexible welding platform[J]. Equipment Operation and Maintenance, 2022(7): 64-68.
MLA Format
Ren, Bo. "Blockage Cleaning Technology and Thread Protection of Positioning Holes on 3D Flexible Welding Platform." Equipment Operation and Maintenance, vol. 7, 2022, pp. 64-68.
APA 7th Format
Ren, B. (2022). Blockage cleaning technology and thread protection of positioning holes on 3D flexible welding platform. Equipment Operation and Maintenance, 7, 64–68.
