As flux cored wires contain powder they can absorb the moisture phenomena, which could lead to welding problems , that could be avoided by respecting the storing and handling procedure or alternatively fixed by the following redrying procedure.
Seamless cored wires are not affected by this phenomenon, which is why it is not recommended to carry this procedure when using seamless cored wires.
- Cored wires should be stored in original unopened and undamaged packaging.
- Storage times should be kept as short as possible.
- Whenever possible, the "first in – first out" principle should be adopted.
- Flux cored wire should not be stored for more than 5 years. Older wire should be redried before use.
- Storeroom temperature should be kept as even as possible, temperature variations should not exceed ± 5°C.
- Temperature should not fall below 15°C. Relative humidity should not exceed 60% at 15 – 25°C or 50 % at 25°C – 35°C.
- Welding should be carried out at room temperature and low relative humidity.
- If relative humidity exceeds 60 %, cored wires should not be left unprotected for more than 24 hours.
- Once removed from the original protective packaging flux cored wires should be used within 72 hours.
- Between shifts, wire spools should be stored in their plastic bag, in the above mentioned storage conditions, relative humidity should not exceed 50 %.
- Wire slightly affected by moisture may be redried at 140 – 200°C for 2 – 12 hours. The recommended cycle is 6 hours at 150°C.
- Up to 6 maximum redrying cycles are possible.
- Cored wires that are rusty or / and have suffered from severe water contamination or that have been exposed to the atmosphere over long periods of time cannot be restored and should be discarded.