K664-2 - Aluminum MIG Conversion Kit .035

Technical Overview: K664-2 Aluminum Feeding Solution

The Lincoln Electric K664-2 is a specialized consumable and hardware kit designed to facilitate the Gas Metal Arc Welding (GMAW) of aluminum using .035 inch (0.9 mm) electrode wire. This kit is engineered to overcome the low column strength of aluminum wire, which often leads to feeding failures when using equipment set up for mild steel. By replacing standard steel-handling components with those optimized for aluminum, operators can achieve stable arc performance and consistent wire feed speeds.

Optimized Feeding Components

Feeding aluminum requires minimizing friction and eliminating sharp edges in the feed path. The K664-2 kit includes a non-metallic cable liner (often Teflon or nylon-based) which provides a low-coefficient of friction surface. This prevents the aluminum wire from abrading against the liner walls, which would otherwise generate shavings that clog the liner and contact tip. The kit also supplies a specific drive roll featuring a groove profile (typically U-groove or smooth) that provides adequate traction on the soft wire without deforming its cross-section, preserving the wire's concentricity for better electrical contact.

Consumables and Filler Metal

Included in the package are six (6) contact tips tailored for .035" aluminum wire. Aluminum expands more rapidly than steel when heated; therefore, these tips are machined with slightly larger bore tolerances to prevent the wire from seizing inside the tip during high-amperage welding. The kit is rounded out with a 1 lb. spool of SuperGlaze 4043 (ER4043). This silicon-aluminum alloy is chosen for its fluidity and wetting action, reducing the risk of hot cracking and porosity in the weld pool. It is suitable for welding 6xxx series base metals and is widely used in general industrial applications.

Application and Compatibility

This kit is intended for use with specific Lincoln Electric compact wire feeder/welders. It allows for the direct feeding of aluminum wire through the standard MIG gun cable (typically limited to shorter lengths, such as 10 ft, to minimize drag). It serves as a cost-effective maintenance and conversion solution for MRO professionals requiring occasional aluminum welding capabilities without investing in push-pull systems or spool guns. Proper installation of the liner and drive roll is essential for performance, ensuring the wire path is free of gaps where the flexible aluminum wire could buckle.