From Factory Floor to Your Workshop: Evaluating a Pre-Owned, Used, Secondhand, Surplus CNC Machine Before Purchase LINCOLN ELECTRIC Sub Arc Welder made in USA
When evaluating a pre-owned, used, second-hand, surplus CNC machine or a Lincoln Electric Submerged Arc (Sub Arc) Welder made in USA before purchase, it’s crucial to assess both general condition and technical capability to avoid costly surprises after installation in your workshop.
Below is a comprehensive, structured guide and technical overview you can use before you buy.
1. Manufacturer & Origin
Brand: Lincoln Electric
Machine Type: Submerged Arc Welder (SAW)
Made in: USA
Lincoln Electric has a long history of producing heavy-duty welding equipment in the United States, particularly large Sub Arc welding power sources, wire feeders, and submerged arc welding systems used in shipbuilding, pressure vessel manufacturing, offshore fabrication, and steel mill applications.
2. Why Sub Arc Welding Matters
Submerged Arc Welding (SAW) is a high-deposition, high-quality welding process where the arc is submerged beneath a flux bed for deep penetration welding with minimal spatter. Common use cases include:
- Long seam welding on plates and shells
- Thick structural welding (15 mm and above)
- Pipe and pressure vessel fabrication
- Welding of high-strength steels
3. Key Technical Specifications to Check
Below are typical specifications for industrial Lincoln Electric Sub Arc welding systems. Actual details vary by model, but these are common figures for used SAW machines:
| Specification | Typical Value / Range |
|---|---|
| Welding Process | Submerged Arc Welding (SAW) |
| Power Source Type | DC or DC Constant Current |
| Input Voltage | 460 / 575 V three-phase (often) |
| Output Current Range | 300 – 2,000 A (depends on model) |
| Output Voltage Range | 15 – 50 V (approx) |
| Duty Cycle | ≥ 60% @ Rated Output |
| Wire Feed Unit | Motorized wire feeder (Lincoln or aftermarket) |
| Flux Handling | Automatic flux delivery and reclaim unit |
| Control Panel | Analog or digital (depending on age/model) |
| Cooling | Water cooler for power source |
| Auxiliary Power | 120/240 V for control circuits |
| Weight (power source) | 500 kg – 1,200 kg+ depending on kVA |
| Protection Class | NEMA 12 / IP23 (often for industrial use) |
4. What to Inspect Before You Buy
A) External Condition
- Cabinet and Finish: Rust, dents, paint condition.
- Fan and Ventilation: Blower fans must turn freely.
- Power Cable Condition: No cracks, overheating discoloration.
B) Electrical Components
- Power Rectifier Diodes: Check if any are short or open.
- Transformers and Chokes: Look for heat damage.
- Control Wiring: Cracks or brittle insulation indicate age issues.
- Contactors and Relays: Listen for consistent operation.
C) Output Performance
- Output Current Test: Use a clamp meter to confirm current capacity.
- Voltage Stability: Ensure stable welding voltage under load.
- Duty Cycle Check: Verify rated duty cycle under real load conditions.
D) Wire Feed and Flux System
- Wire Feed Unit: Smooth feeding with no slipping.
- Drive Rolls: Adequate grip and condition of grooves.
- Flux Hopper: No damage and free actuators.
- Flux Recovery: If equipped, ensure recovery unit works.
E) Cooling System
- Water Cooler: Check pump, radiator condition, leaks.
- Flow Rate: Adequate coolant flow without obstructions.
F) Safety Features
- Grounding Lugs: All present and clean.
- Emergency Stop: Works as intended.
- Interlocks: Doors and safety covers.
5. Load Test (Recommended)
Always run a load test before purchase:
- Connect to appropriate power source (often 460V/3Ø).
- Set output to moderate range (e.g., 600–800 A).
- Weld on a test plate of similar thickness to your intended use.
- Check:
- Arc stability
- Wire feed consistency
- Duty cycle performance
- Heat stability over 30–60 minutes
Document results with photos and measurements if possible.
6. Typical Use Cases for a Used Lincoln SAW Machine
- Industrial fabrication shops
- Railcar and bridge welding
- Shipyard welding stations
- Pressure vessel and boiler welding
- Fabricating thick structural components
7. Common Service Parts to Budget For
Even if the machine tests well, inspect or consider replacing:
- Electrolytic capacitors (dry out over time)
- Cooling pump seals
- Fan motor bearings
- Rectifier diodes or modules
- Wire feeder drive rolls and liners
Summary
A Lincoln Electric Sub Arc Welder made in USA is a robust machine. When evaluating a used unit before purchase, pay attention to:
- Overall electrical integrity
- Output performance and duty cycle under load
- Mechanical condition of wire feed and flux system
- Cooling system functionality
- Clean ground and safety features
Proper inspection and testing can save thousands in repair costs and ensure the machine performs reliably in your workshop environment
