Bohler UTP 39 (Joining & Repair-Stainless steels) Special application Stick Electrodes
Bohler UTP 39 are basic coated pure copper stick electrodes engineered primarily for joining and surfacing commercial pure copper grades rather than stainless steel. Yields a weld metal deposit with greater than 97.0% pure copper content for high electrical and thermal conductivity. Suitable for joining and surfacing commercial pure and oxygen-free copper grades (such as DIN 1976 standards), frequently used in electrical engineering, fabrication, and apparatus construction where matching the high thermal/electrical conductivity of pure copper base metal is essential.
Features
- The slag covers the weld pool evenly to protect the molten copper from atmospheric contamination (which causes oxygen porosity).
- Once cooled, the slag lifts off easily, reducing post-weld cleaning time and making multi-pass cleaning efficient.
- While copper is ideally welded in the flat position due to fluid weld pool dynamics, the electrode provides good puddle control for managing joint angles
- The basic coating provides a concentrated, stable arc, which is necessary to combat the massive heat dissipation that occurs when welding copper.
- It delivers a clean, smooth metal transfer with minimal spatter, resulting in an exceptionally clean weld bead appearance.
- Designed to run on DC+, it ensures maximum heat generation at the weld pool, helping to overcome copper’s high thermal conductivity
Technical Data
- AWS A5.6: ECu (mod.)
- EN ISO 17777: E Cu 1893 (CuMn2)
- Copper base metal must be preheated to 400°C – 600°C depending on the thickness of the wall, and this temperature must be held steady throughout the entire welding process.