The value of welding consumable trials

A welding consumables trial in an automated welding operation is often shorter because of the consistency and speed of the welding robot. Feedback is faster.

In both semiautomatic and automated welding cells, the upfront cost of welding consumables is low compared to the overall expense for equipment, materials, and labor. Yet when companies accrue downtime for excessive welding contact tip changeover or troubleshooting poor wire feeding associated with liner issues, costs can quickly compound.

At times, companies may try to mitigate consumable problems without a true sense of the root cause, implementing a solution without data to back up the decision. However, conducting a welding consumables trial can provide insight into whether an operation is using the best consumables for the application.

Welding contact tips are the baseline for these trials since they are the most frequently changed consumable. Nozzles and diffusers that are compatible with the contact tip are included in a trial but not monitored in the same way since they last much longer.

The Benefits of Weld Trials

Companies might be hesitant to conduct consumables trials. Some might resist potential change or be concerned that the change will bring higher initial costs for products. Some companies might worry about taking time away from production to complete the trial. That can especially hold true if accounting or procurement notices increased spending for welding consumables and the management team feels pressured to implement a quick fix.

But proceeding with welding consumables trials can bring benefits by uncovering opportunities for improvement. They allow companies to:

• Gain a true understanding of their existing contact tip lifespan.
• Determine the current frequency of welding contact tip changeover to establish a baseline for adding efficiencies.
• Uncover welding liner issues that may be adversely affecting contact tip life.
• Establish an accurate view of the amount of downtime accrued for contact tip changeover.
• Look at the benefits of alternative consumables objectively, based on data.
• Assess the upfront cost of consumables versus the cost of downtime.
• Define the true cost of welding and the projected return on investment associated with a welding consumable conversion.

The trials for semiautomatic and automated welding operations have their own requirements, but both require time to gather data to make an informed decision. For companies with both types of operations, there can be added value. A trial may reveal the opportunity to standardize on a single contact tip to minimize inventory management and costs and eliminate the risk of the wrong tip being installed on a welding gun.

Trials for Semiautomatic Welding Cells

Companies may not realize the extent of their consumables problems until a trial begins. The process starts with a discovery meeting, typically between a welding consumables manufacturer and a plant or general manager. A welding distributor may be involved as well.

During the discovery phase, the goal is to uncover the problems that the company has been experiencing with its existing welding consumables. These could include frequent burnbacks, or the burning back of the welding wire into the contact tip; poor wire feeding; bird-nesting, or the tangling of the welding wire in the drive rolls; excessive contact tip usage or costs; keyholing, or the oblong wear of the bore in the contact tip; excessive heat; resistance built up in the gun and system; chatter; and an erratic arc. Consumables trials usually take two to three weeks but may last up to a month or more depending on the company’s comfort level with the process.

The existing welding gun and the one being trialed with the alternative consumables should be the same amperage and used for the same application. The consumables should also be the same material, such as copper. In this way, the comparison is equal.

During a consumables trial, it’s important to operate the existing welding gun and consumables for a period of time to gather baseline data. Then companies should switch to the new consumables and repeat the process. The aim is to use the contact tips until failure, tracking the amount of the existing product and the number of alternative tips used during this period. The contact tips should be collected so that they can be assessed for the type of failure that is occurring and to confirm that they truly have failed. Having an experienced welder and a newer one participate in the trial can reveal more details about contact tip failure, since they will have different welding techniques that could affect results.

Welding consumables trials can bring benefits by uncovering opportunities for improvement.

Once the trial is complete, companies can calculate the overall annual cost of each welding contact tip based on the amount used. The calculation considers not only the upfront cost of the tip but also the labor expense for changeover based on a welding operator’s hourly wage rate to make a comparison between the two types of contact tips.

Often this comparison will reveal that the existing welding contact tips were being changed out too frequently, out of habit, or that they were not lasting long enough to meet the demands of the application. The trial also can point to contact tip issues that have been caused by liner problems, which is the case most of the time. That is especially important to address since welding liners are the most expensive consumable in a welding gun and the most time-consuming to change over.

During the trial, it’s important to gather feedback from the welding operators and actively engage them in discussions about a possible conversion. Since they use the consumables daily, their opinion and buy-in are valuable.

Trials for Automated Welding Cells

The process for trialing consumables in an automated welding operation is much like that for a semiautomatic one, beginning with a discovery meeting. Again, it is important to determine what problems are occurring in the welding cell. Typically, the same issues that happen in a semiautomatic welding operation will also occur in an automated one, with the addition of tool center point (TCP) disruptions.

A welding consumables trial in an automated welding operation is often shorter because of the consistency and speed of the welding robot. Receiving feedback is faster. This, along with the robot’s repeatability, allows for trialing multiple types of contact tips, such as copper, chrome zirconium, or those designed for high-deposition pulsed welding if that is being used. There isn’t the concern over variation in techniques that occurs among welding operators in a semiautomatic operation. The trial usually takes place in a single weld cell. If there are multiple robots within that cell, the contact tips can be trialed on all.

Even though the automated welding trial can be completed faster than the semiautomatic one, it’s important to establish a baseline. For example, if a company only changes its existing contact tip once a day, then the trial period would be extended to gain a larger number of comparisons. That’s in contrast to an operation that uses one tip every two hours, in which case information can be collected more readily. In either case, the welding contact tip needs to be run to failure to gather the necessary data.

This data can be collected manually or through the assistance of weld data monitoring. The software allows access to even more information during the trial. Weld data monitoring shows voltage drops and peaks in amperage that affect welding contact tip life, so companies can understand the exact time between changing the tip to the time it fails.

Comparing the number of existing contact tips used during the trial to the alternative product, along with the cost of each, allows companies to make an informed decision about which consumable to use. Namely, it can reveal the potential for reduced downtime, even if an alternative contact tip costs more up front. Fewer changeovers mean more arc-on time and less expense for labor to complete the process.

Reassessing Consumable Performance

Companies considering a welding consumables trial should keep an open mind about the possible conversion and look objectively at the resulting data. Equally as important is to determine the cadence of implementing new consumables if a conversion turns out to be the best choice.

Some may prefer to change over welding cells all at once, while others opt to add the new products slowly. As with any change in the welding cell, if a conversion occurs, it’s important to continue monitoring the products to ensure that they are providing the desired performance. Change is not a one-time event but instead part of an ongoing assessment.

Gather feedback from the welding operators and actively engage them in discussions about a possible change. Since they use the consumables daily, their opinion and buy-in are valuable.