Lincoln Nic-L-Weld 99 ENi-CI — Overview
Lincoln Nic-L-Weld 99 is a AWS A5.15/A5.15M ENi-CI pure nickel (99% Ni) SMAW electrode designed specifically for welding and repair of gray cast iron, ductile iron, and malleable iron. The high-nickel deposit is fully machinable after welding — a critical property for cast iron repair where weld metal must be machined, bored, or threaded to restore dimensional accuracy. The ductile nickel deposit accommodates the expansion stress of the weld without cracking in the heat-affected zone of cast iron, the primary failure mode of carbon steel electrodes used on cast iron. Nic-L-Weld 99 is the Lincoln Electric standard for cast iron welding in automotive, agricultural equipment, machine tool, and general maintenance applications. DC− (DCEN) or AC; all positions. Available at WeldingMart as an authorized Lincoln Electric distributor.
Specifications
| AWS classification | AWS A5.15/A5.15M ENi-CI |
|---|---|
| Deposit alloy | ~99% Nickel |
| Coating type | Graphite-coated, low-flux |
| Polarity | DC− (DCEN) preferred; AC acceptable |
| Welding positions | All positions: flat, horizontal, vertical, overhead |
| Machinability | Fully machinable deposit |
| Tensile strength (deposit) | ~40,000–50,000 psi (minimum per AWS A5.15) |
| Typical current range | 3/32 in: 40–70 A | 1/8 in: 65–95 A | 5/32 in: 90–130 A |
| Available diameters | 3/32, 1/8, 5/32 in |
| Manufacturer | Lincoln Electric |
| Standards compliance | AWS A5.15/A5.15M ENi-CI |
Applications & Industries
Nic-L-Weld 99 is the first-choice electrode for cast iron repair and fabrication requiring machinability:
- Automotive engine components: Cracked engine blocks, cylinder heads, exhaust manifolds, and brake components — wherever cast iron requires dimensional restoration and machining after welding
- Agricultural and construction equipment: Cast iron gear housings, transmission cases, pump bodies, and hydraulic components that need precision bore repair
- Machine tools and industrial equipment: Machine bases, lathe beds, and machine tool castings where crack repair must be followed by surface grinding or machining
- Pipe fittings and valves: Gray iron and ductile iron pipe fittings, valve bodies, and pressure-rated castings in maintenance applications
- General maintenance and repair: Field repair of any cast iron component where cold welding (low preheat) technique and machinability are required
Process Technology — How to Weld Cast Iron
Welding cast iron requires specific technique to prevent cracking — the most critical variable is thermal management:
- Preheat options: Full preheat (500–1200°F for thick sections) produces the least risk of HAZ cracking but requires controlled slow cooling. Cold welding (no or minimal preheat — 100–200°F) uses short-bead deposition to minimize heat input; acceptable for small repairs and machinable nickel deposits.
- Short-bead technique (cold welding): Deposit no more than 1-inch beads at a time. Allow each bead to cool before placing the next. Peen the bead while hot (immediately after welding) to relieve stress.
- Amperage: Use the minimum amperage that produces a sound bead. Lower heat input reduces thermal shock and HAZ cracking risk. Start at the low end of the current range.
- Polarity: DC− (DCEN) is preferred — it produces a lower-heat arc that reduces dilution and HAZ heat input. AC is acceptable when DC− is not available.
- Stringer beads: Do not weave on cast iron. Stringer beads minimize width of the HAZ and reduce stress concentration.
- Slow cooling: After welding, cover the casting with an insulating blanket, vermiculite, or dry sand to slow the cooling rate and reduce thermal stress. Do not quench with water.
- Groove preparation: V-groove or U-groove the crack to clean base metal. Remove all contamination (oil, grease, carbon deposits) from the repair area.
Storage & Handling
- Store in original sealed packaging in a dry location at ambient temperature
- Nic-L-Weld 99 is not a low-hydrogen electrode — standard dry storage conditions are sufficient
- Protect from moisture and contamination; keep electrodes clean and dry
- For long-term storage, a standard electrode cabinet or sealed container is adequate
Frequently Asked Questions
- What electrode is best for welding cast iron?
- Pure nickel (ENi-CI) electrodes such as Lincoln Nic-L-Weld 99 are the preferred choice when a machinable deposit is required — cracked engine blocks, cylinder heads, and gear housings that must be machined after repair. Nickel-iron (ENiFe-CI) electrodes offer higher strength and better crack resistance and are used when machinability is less important than joint strength, such as for structural cast iron repairs.
- Why can't I use a regular 7018 electrode on cast iron?
- Carbon steel electrodes (6010, 6013, 7018) deposit weld metal with high carbon pickup from the cast iron base metal, creating a very hard, brittle zone in the weld and HAZ that cracks during cooling. The nickel in ENi-CI deposits does not form hard carbides, remains ductile, and can accommodate the thermal stresses of cast iron welding without cracking.
- Does welding cast iron require preheat?
- It depends on the section thickness and repair type. For thin sections and small repairs using the "cold welding" short-bead technique, minimal preheat (100–200°F) is used to limit heat input. For thick castings or critical structural repairs, 500–1200°F preheat with controlled slow cooling is preferred to eliminate the thermal gradient that causes HAZ cracking. Nic-L-Weld 99's ductile nickel deposit is most forgiving of the cold welding approach.
- Is Nic-L-Weld 99 machinable after welding?
- Yes. The high-nickel (ENi-CI) deposit is fully machinable — it can be drilled, bored, threaded, turned, and surface-ground to restore dimensional accuracy after welding. This is the key advantage over steel electrodes and the reason nickel electrodes are specified for engine block and precision casting repairs.
Browse specialty electrodes: Stick Welding Electrodes & Rods — or see Lincoln Excalibur 9018-B3 MR for alloy steel applications.