Microwelding: Then and now

Equipment, technology evolve to meet demands

THE FABRICATOR® MAY 2006

May 15, 2006

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Like the molds he repairs, Five Star Tool Welding owner Joe Canfield finds that the welding equipment he uses at his company is getting smaller and smaller. Over the years GTAW equipment has evolved to better meet the needs of its tool and die welding users.

Five Star Tool Welding General Manager Steve Coleman repairs damaged areas to a plastic mold insert.

Joe Canfield is a grateful tool and die welder. That's because he gets to use gas tungsten arc welding (GTAW) and micro-GTAW—a major upgrade from the original version of tool and die welding.

In the beginning, he explained, an atomic hydrogen welding machine did the work he does today; a machine he said wouldn't look out of place in an old Frankenstein movie.

An atomic hydrogen welding machine uses hydrogen gas and two tungsten electrodes, he explained. The arc from one electrode moves to the other, and the arc breaks down the hydrogen going through the arc and reassembles itself outside the arc. This is what produces heat, which can reach 5,000 degrees, Canfield noted.

"That's what they first used for tool and die welding," Canfield said. "You could overheat the steel and really just burn it. It was very loud."

Today's microwelding story is quite a bit different for Canfield.

Why Micro-GTAW?

Canfield started out in the tool and die welding business in 1967 as a summer truck driver for a tool and die welding company in Wisconsin.

"It [tool and die welding] was pretty infantile at the time," he said.

He was set to go back to school to continue his education to become a woodworking teacher, but took a chance and joined the company instead.

After 20 years working in the tool and die business, Canfield decided it was time to start his own company. He opened Five Star Tool Welding Corp., Butler, Wis., in 1987.

Thanks to his networking in the tool and die industry, one aspect of starting a business was no problem for Canfield: a customer base.

"I had people waiting outside my door," he said.

The damaged pad on this plastic mold insert was built up 0.0005 inch using micro-GTAW.Five Star Tool Welding repaired the damaged edge on this plastic mold core pin.

His one mission when he opened his doors, though, was to buy equipment. For Canfield, it was as simple as getting jobs, getting paid, and investing in new equipment. This system has flowed relatively smoothly, he said.

Canfield's company uses 60 percent micro-GTAW and about 40 percent GTAW for its 400 customers, 200 of which are active throughout the year. Once in a great while the company will shielded metal arc-weld (SMAW) a cast-iron machine part.

And, he said, business is growing.

"Tool and die technology is changing," Canfield said. "Molds and dies are getting finer and finer. The die could be huge, but with very fine detail. Some dies weigh only an ounce, and others weigh thousands of pounds."

Materials also play a role in the evolution of tool and die welding.

"One of the things that has changed is the type of steels that are on the market and their uses," Canfield said. "We work with some steel manufacturers when they introduce a new steel. [We] see what it takes to weld it."

And, of course, Canfield has seen changes in the tool and die companies themselves.

"Tool and die companies that have survived will be around for a while because they've tightened their belts," he said. "They're a little leaner than they have been."

GTAW as Standard Practice

One thing that hasn't changed—at least, since the 1960s when GTAW debuted—is that GTAW is a staple for most tool and die welders.

"Use of TIG welding is the most common," Canfield said.

Canfield admitted that laser welding has its place, but not in his shop, as Five Star focuses on micro-GTAW.

Made of S-7 tool steel, this die cast die insert required repair on its damaged ring surface.The damaged edges on this Dynacas™ die insert were repaired using micro-GTAW at 10 to 15 amps.

"Some of the companies doing laser welding have sidelines like mold polishing, chrome plating—something to assist the laser welding part of it. Others sell the equipment," he said.

But even for a process that has become standard practice for many tool and die welders, equipment modifications have taken place over the years.

The power source has changed the most, according to Mike Sammons, sales and marketing manager for Weldcraft, Appleton, Wis. Ten or 15 years ago, he said, these machines were the size of dishwashers. Today they can be as small as a lunchbox.

It's also less difficult to operate a GTAW power source today, Sammons said. This is a big improvement over the machines that needed special care to use.

"Today you turn a switch and it's like taking a '57 Chevy and turning it into a Lamborghini," Sammons said.

Torches also have shrunk over time. All the components—from the torch itself to the collets, collet bodies, nozzles, and gas lenses—are smaller. These days gas lenses are even made of different materials, such as Pyrex® glass, to aid the welder's vision in confined areas. Tungstens also are smaller and require special grinding or preparation techniques, Sammons said.

All of these changes are necessary to help make the microwelder's job easier, Sammons said. "Easier" in this field mostly means better control of the arc, which is critical with such tiny jobs, critical parts, and specialty alloys.

"You're talking thin materials, specialty alloy-type materials or superthin materials for military, aerospace, and medical, and then you get into tool and die, [which] may take you an hour to set up, [but] the actual weld time is a couple of minutes. Then you have a couple of hours of postweld treatment to make it look like it did," Sammons said.

Canfield is one tool and die welder who can appreciate the changes that have taken place in GTAW. He sees a long future ahead of him with the process.

"The machinery has evolved to make our job a lot simpler because of TIG welders with a very low amp output to control the arc, optics such as microscopes, and the diameter of rods we've used," Canfield said. "It's [GTAW] going to be around for a long time because no one else has come up with a better way to repair tools and dies. TIG technology is very clean welding, and with a skilled welder, you can do anything with it."

Five Star Tool Welding Corp., 12575 W. Custer Ave., Butler, WI 53007, 262-783-5822, www.fivestartoolwelding.com

Weldcraft, 2741 N. Roemer Road, Appleton, WI 54911, www.weldcraft.com



Stephanie Vaughan

Contributing Writer

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