When it comes to welding, much attention goes into selecting the right power source, establishing the correct welding parameters and implementing the appropriate welding operator training to gain the best results. Selecting the right filler metal is equally important. So, too, is knowing how to protect that purchase with the right handling and storage techniques.
Proper filler metal handling and storage not only helps reduce unnecessary costs for damaged products, but it also helps ensure the best performance and weld quality. Whether welding takes place in a large manufacturing facility, a small shop or in the field, the goal is to keep filler metals – from stick electrodes to solid, flux-cored and metal-cored wires – in the same high-quality condition as they were received from the manufacturer. Here are some tips.
Filler metal damage can come in many forms. Moisture is the most common, but dirt, oil, grease and other contaminants can also pose a problem. In most cases, such damage will void the manufacturer’s warranty for the product, leading to extra cost to obtain and inventory the replacement filler metal on top of disposing of the ruined welding wire or stick electrodes.
Filler metals ship in vacuum or hermetically sealed packaging or are placed in a heavy plastic bag or wrap to protect them from contaminants. To help maintain their original condition, there are several key steps to take.
When removing filler metals from their packaging and preparing them for welding – such as placing a stick electrode in a holder or a spool of wire on a feeder – it is important to always wear clean gloves. Solid wire, in particular, can easily pick up sweat from bare hands. This moisture can lead to rusting and cause poor wire feeding or, potentially, porosity in the finished weld. Moisture can also lead to hydrogen-induced cracking.
For wire welding operations, use an enclosed wire feeder when possible to protect the filler metal from airborne contaminants in the environment. Remove the wire spool if that particular machine and wire feeder will not be in use for an extended period of time, as the enclosure cannot fully protect against damage. This is especially true for facilities or shops that generate a significant amount of dust, such as those employing plasma or oxyfuel cutting systems.
In these environments, it is also important to store unused filler metals in an area that can prevent cutting dust from accumulating on the surface of the wires. Dust can cause poor wire feeding or clog the contact tip and nozzle, resulting in poor electrical conductivity and an unstable or erratic arc. Dust that accumulates on stick electrodes typically leads to porosity in the weld. Both instances can cause costly downtime for rework and for replacing the damaged filler metals.
Filler metals that have been opened but are not in use should be stored properly at the end of the workday or shift. Remove the wire spool from the wire feeder and place it in a clean plastic bag, closing it securely. Store the bag in the original box in a clean, dry area until it is ready for use again. If it is not feasible to remove the spool from the feeder, cover it securely with a plastic bag to gain some amount of protection.
Filler metals should be kept in a dry area ideally the same temperature as where the welding will take place. Moving from a cold area to a warm area, for example, can lead to condensation and cause the filler metal to absorb moisture. In the event that the storage and welding environments are different temperatures, allow the filler metal to acclimate to the temperature where it will be used as added protection against moisture pickup.
Unopened filler metal packages should always be stored away from water, oil, grease or other similarly damaging elements.
Stick electrode consideration
For fabrication applications and welding in the field, stick electrodes are commonly used and require special attention when it comes to storage and handling. Protecting stick electrodes against moisture is the No. 1 goal. Stick electrodes can absorb moisture even more so than solid, flux-cored and metal-cored wires, which can lead to hydrogen-induced cracking, porosity and many other weld discontinuities that could lead to downtime for rework.
Stick electrode packaging, typically a can or carton, should never be left open. Depending on the type of stick electrode, they must often be stored in a holding (or rod) oven at a specific temperature after opening to protect them from moisture. Filler metal manufacturers prescribe specific oven storage and holding temperatures for each type of stick electrode. In some cases, a specific welding procedure or code may dictate how long a package of stick electrodes can remain open before it must be discarded – regardless of whether it has been stored in an oven or not. It is important to always follow the welding code specifications for the job, as well as the filler metal manufacturer’s instructions for a particular stick electrode.
In the event that stick electrodes have been exposed to moisture, follow the recommended procedure for reconditioning – placing the damaged electrodes in an oven at a given temperature for a specified period of time. Filler metal manufacturers provide reconditioning directions in each package.
Note that welding wires should never be reconditioned. Similarly, stick electrodes bearing the American Welding Society (AWS) classification E6010 and E6011 should not be stored in an oven and cannot be reconditioned. These stick electrodes require a specified level of moisture in the coating to perform properly and create a quality weld.
As added protection, look for stick electrode packaging options that provide greater moisture resistance. These include wax-coated cartons or plastic packages.
Keeping filler metals in the best condition possible is among several means of establishing good weld quality, maintaining compliance with the specified welding parameters and eliminating unnecessary downtime or costs. To achieve this, training is key.
Therefore, it’s advantageous for business owners to offer the appropriate filler metal handling and storage training and always encourage welding operators to engage in these best practices. By taking these simple steps, businesses can ultimately yield many positive results, leading to better productivity and greater savings in the welding operation.