The contact tip is the last piece of welding equipment before the electrode wire contacts the workpiece. But it tends to be the first piece of equipment the customer blames for any welding issues that come up.
“When they have a welding problem, customers tend to lead with ‘it’s the tip,’ but really, it’s rarely ever the tip when problems start happening,” says Travis Hall, Lightning MIG product and operations manager at American Torch Tip Co. To exemplify the frequency in which fingers are pointed at the contact tip, Hall shares a complaint that just crossed his desk. Although the culprit hadn’t yet been identified, someone at a shop was blaming their problems on the tip. Most likely, hall says, it’ll be one of 10 other causes.
The potential causes that Hall mentions can start at the power supply and wire feeder and end at the tip. Problems, he says, can show up anywhere in between.
“When we go into a customer’s shop, we look at the whole setup to see where the problem may start or if we can suggest any improvements,” Hall says. “We like to create value by working to solve customers’ pain points, even the ones of which they might not be aware. We bring in best practices on part management, part type and the process when we can.”
Even shops that have their programs down pat can benefit from an outside set of eyes.
Typical signs of a problem with the welding system include voltage drops, erratic wire feeding, erratic arc, overheating welding guns, contact tip burnback and shortened life, and excessive spatter.
Fortunately, a lot these issues can be solved with proper maintenance and setup. One of the first items to check for is faulty ground clamps and loose connections throughout the welding system.
“You’re not going to get a good connection if your ground clamps are loose, dirty, worn or disintegrated,” Hall says. “That creates electrical resistance and heat back through the gun. Bad grounds are one thing people can fail to diagnose because they can be easy to overlook and are key to a good consistent arc. But it’s an easy check to see that all of the connections are clean and tight.”
Tight rolls
For a lot of welders, at the first sign of a wire feed issue, they tighten down the drive rolls on the wire feeder. But that might not solve the problem – and furthermore, it could introduce other issues.
“If the wire stops or is feeding erratically, instead of looking for the cause, the welder tends to crank the drive rolls down,” Hall says. “Overtightened drive rolls can deform the wire and create wire shavings in the feeder, which then wears the liner and tip prematurely and creates more shavings inside the gun liner.”
Hall notes that shavings can cause poor wire feeding, birdnesting and burnback. Compounding the issue, he also notes that the knobs on the drive rolls used for setting the tension oftentimes have tool marks on them and are sometimes even missing. Welders try not to resort to using tools here, such as pliers, as the knobs are meant to be able to be tightened by hand. And even if the overtightened drive rolls aren’t causing immediate problems, the feeding equipment experiences unnecessary wear and tear in the long run.
“We work to understand why the welders have the drive rolls overtightened (besides the fact that it’s simply how they like them),” Hall says,” and explain that if they are forced to continually tighten them down, there’s probably another issue in the system. We stress the fact that they need to address the real issue first and then set the proper tension, reminding them not to just tighten down the drive rolls as the quick fix.”
These simple conversations can result in big savings. Recently, ATTC was able to help a local customer save an estimated $9,500 a year – on parts alone. After routine testing, savings were achieved just by correcting the basics, a major component of that being the wire feeding process and drive roll tension.
“We monitored consumable usage for a few weeks without changing anything,” Hall says. “We then put our test into play, putting new drive rolls on all the wire feeders and making sure they had the optimum tension. We checked each station every other day to readjust the drive roll tension, if needed, to keep our test data as true as possible. If we did find drive roll tension had been cranked down, we would work to find out why and eliminate the cause.”
Other maintenance was performed, too. ATTC ensured all connections were clean and tight, checking ground clamps, blowing out or changing gun liners and trimming to the correct length, checking inlet outlet guides and cleaning wire feeders.
Check points
Other basic inspections can include checking the cable for cuts, bends and other damage, and checking for damage to the handle and trigger. The neck as well can have loose connections that can cause poor electrical conductivity.
“Everyone knows some welders have a bad habit of using their guns as hammers,” Hall laments. Even so, ATTC offers a lifetime warranty on its switch and Lightning MIG gun handles, which are made from a virtually indestructible, specially engineered, impact modified nylon 66. “We have run them over with forklifts and hit them with sledgehammers as part of our quality control,” he adds.
The gooseneck, too, tends to suffer abuse as welders try to knock off spatter buildup. Beyond the gooseneck, spatter can build up inside the nozzle and obstruct gas flow. It’s important, however, to note that the nozzle and nozzle insulator can become damaged from heat and cleaning out the spatter. Welding pliers are the most common tool for cleaning nozzles, but other specialized tools are available.
Because of their exposure to heat and spatter, MIG consumables, in general, require frequent replacement. The nozzle alone should be checked and cleaned several times per day. If it appears to be deteriorating or losing shape, it must be replaced.
One of ATTC’s railcar customers was using a nozzle with just a white silicone resin insulator in it. However, most nozzles these days have a brass insert inside the white insulator that makes the nozzle stronger and last longer. After the customer switched, the welders noticed an increase in nozzle life right away.
“Brass nozzles can provide great spatter protection but are typically meant more for light- to medium-duty applications,” Hall says. “Copper nozzles can withstand high heat and are more durable in high amperage applications. This customer did not particularly like the word copper brought up in the same sentence with the word nozzle. We had discussed other options, which they had tried, and ended up back with brass, even with the cracking issues, because of its better spatter resistance.
“Although the customer had noticed increased life with our heavy-duty brass nozzles, they were still challenging us for something more. So we decided to combine the best of both worlds. We designed a two-piece nozzle for them where the majority is copper and can take the abuse and heat much better, and the front is a replaceable brass piece. This will allow them to keep the base and just change the front end several times.
The tip top
After close inspection of the various aspects of welding equipment, the contact tip is the final consumable to review. There are, of course, times when the tip could use a second look.
The tip is critical to the success of the welding operation. It is important to buy tips from a premium supplier that provides tips with a consistent and smooth ID and can help choose a new tip or solve problems that could be a tip-related issue. Otherwise, tips can and will be a constant source of problems.
One area that is sometimes overlooked with contact tips is new products that often boast newer, better technology. Newer styles and materials used in contact tips can last from two to seven times as long as older ones, which can add up to a huge cost saving on many levels.
“We did a large conversion last year where we ended up sending around 400 guns on five pallets,” Hall says. “The customer was using tips that were popular quite a few years ago, but that you don’t see very often today. It is more about the connection the tip makes to the mating pieces (seating surface area). The cooler the setup runs, the longer it’s going to last so it was easy to go into the customer’s facility and get them longer tip life.”
For ATTC Lightning tips, they have a taper and a thread. Most of the contact, therefore, is made on the taper and some contact is on the thread, so there are two points for electrical transfer. The taper allows for a secure and complete 360-degree seating surface, allowing for much cooler running consumables. These tips can last at least two to four times longer than older tips or tips with just threads, and sometimes they can last up to six or seven times longer.
Also, dual threads allow the contact tip to be reseated 180 degrees so there is a new wear point, which can extend the life of the tip.
Another issue that comes with contact tips is tightening them. “We’ve had to do training on the tips to show customers how to tighten them using the proper welding pliers. When you have a range of skill sets and expertise at facilities, it is important to train and have standards for this, especially with changeover. Also, if you change or are used to a certain tip or product, it may need to be tightened a little differently than the previous one. It’s also important not to score the tip with the pliers by just cranking around the edges because it can damage the tip.”
Some contact tips have flats on them, and other tips don’t have flats and are completely round with no sharp edges where spatter can adhere. Some people like the flats because it gives them something to grip with the pliers. But even with the flats, you still need to make sure your tip is secure.
A final look
Of course, welding problems could be caused by the wire or gas being used. Having the proper gas and wire combination can help enhance arc performance and keep the gun cool. Although these areas are not ATTC’s expertise, it can still offer suggestions if it notices something obvious.
“We had a customer that was starting an aluminum job where they couldn’t achieve enough penetration,” Hall says. “We suggested a specific helium argon mixture to allow them to get the penetration needed for a strong weld.”
While Hall believes customers are aware of the various variables involved with welding, “when you are in the weeds sometimes it can all get lost,” he says. “Sometimes, a new set of eyes can help. We can work with the welding engineers together to solve problems. And, we can learn a lot from our customers at all levels as they are the ones in direct contact every day with a lot of types of applications.”
ATTC likes to offer support, which sometimes seems to be a forgotten about these days. While it’s important to respond quickly to customer, good strong relationships and open lines of communications have been the key to continued success over the past 77 years.
