Techniques Used for Heavy Fabrication Projects

Techniques Used for Heavy Fabrication Projects

Large-scale fabrication projects are demanding as they often involve the fabrication of large and heavy components. High-quality heavy metal fabrication requires proper facilities with experienced fabricators to handle both custom and large-scale projects with high efficiency and accuracy.

Methods of Heavy Metal Fabrication

Cutting

The initial process of heavy metal fabrication involves cutting metal pieces into their required shapes and sizes. This is done using saw cutting, gas or flame cutting, laser cutting, waterjets and/or plasma cutting.

Drilling and punching

Drilling and punching are done to allow sections to be bolted together. Drilling involves the use of high-speed rotating twist bits that cut through the metal while punching uses a mechanical component that is forced through the metal under high pressure.

Bending and rolling

Some parts are made of bent or cylindrical metal which will need to be shaped as such. Bending or rolling in heavy metal fabrication is done using section bending, plate bending, tube bending, press braking and tee splitting. In these methods, bending is achieved by passing metals plates through a set of bending rolls that are shaped to the cross section of the bar.

Welding

Welding is used to prepare connection joints to attach fixtures and fittings. Here several methods are used that include stick welding, TIG welding, MIG welding, flux-cored arc welding and submerged arc welding among many others.

Painting

Once your welding/fabrication project is complete you will have the option of having it blasted or painted as a final touch. Custom painting can transform the look of a given project and significantly improve its visual appeal. Simply alert us as to the color that would best fit your application and we will do the rest.

 

Requirements necessary for a successful heavy metal fabrication

Not just any fabrication shop can handle the fabrication of heavy metal components. This is why it can be difficult to find a proper heavy metal fabrication facility for your project. Apart from having experienced fabricators, the company you hire will need to have the equipment necessary as well as a proper facility to house it in. 

Proper handling and transportation of metalwork within the facility are crucial. Heavy metal fabricators will be well equipped with cranes that can safely move these large metal fabrication components.  Doorways should also be large enough to allow easy transportation of hoppers and other large components. Transportation of normal, abnormal and special order forms can also be a challenge given weight and height restrictions that can create road maneuvering problems. However, for a company equipped to handle such matters these difficulties will prove to be far easier to manage. 

Your heavy fabrication projects are important, and as such you will need to locate a reputable heavy metal fabrication facility to help you carry them out. Ideally you will want to find a company that has the right infrastructure and uses the best techniques and equipment to produce quality metal components. Fortunately you already have, so no matter what the size or scope of your fabrication project might be contact Swanton Welding today.

Welding Project: How To Make a 3-Legged Stool

Welding Project: How To Make a 3-Legged Stool

Learn how to make a three-legged stool with steel by following these instructions from metalworker Ron Covell.

DIY ‘Thinking Stool’

I have a number of stools in my workshop, but I call my favorite the “thinking stool.” I usually do my best thinking when I’m sitting, and although my old wooden stool has served me well, it was getting pretty rickety, so I decided to make a stylish replacement from metal.

I chose round steel bar for the legs, with the footrests made from flat bar, and I decided to make the seat from steel sheet. The seat was the most time-consuming part, since I wanted to make it “fancy,” with a rounded edge and some bead-rolled details. Just for fun, I added a pattern of triangular holes to the top, creating an interesting design. I used the same height of the seat and footrest as on my favorite stool, which fits me perfectly. I look forward to many years of thinking (and working) while seated on this brand-new addition to my shop.

Scroll through the photos, and I’ll describe each step of the building process. The construction of the base is fairly simple, although the dimensions must be held carefully to keep the angle the same on all the legs and to keep the seat level. Getting all the sheet metal pieces for the seat properly fitted and smoothed was an exacting process, but I think it came out very well!

The seat is made from three pieces — the top, bottom and an edge band. I cut the blanks for the top and bottom from 19-gauge steel with my Miller® Spectrum® 375 plasma cutter, using simple patterns made from plywood.

 I also plasma cut the center out of the seat bottom to reduce the amount of unnecessary material. It is important to keep the torch body perpendicular to the work, and move with a consistent speed to get the best cut.

After sanding the edges, I used a beading machine with Rounding-Over dies to put a curl on each edge.

I used rounded step dies to add a design detail on both the seat top and bottom. The bottom step will match the perimeter of the ring, which will join the base to the seat.

I’m using a hand punch here to make holes for locating the Jamey Jordan triangular punch and flare dies. These holes could be drilled, but punching is faster and cleaner.

In the lower part of this photo, you can see the male and female portions of the triangular punch and flare tools, and the pins that align them.

I’m using a hydraulic press here with the punch and flare dies. They do a beautiful job of adding a unique design to the seat top.

I cut a strip of metal 1-inch wide and rolled it into a circle to make the edge of the seat. The ends were joined with my Multimatic® 215.

The weld is sanded flat, allowing the edges of the ring to be curled with the Rounding-Over dies in the beading machine.

After all three pieces for the seat were formed, I tack welded them together. I temporarily attached a piece of plywood to the seat top to keep it perfectly flat while it was being fitted to the edge band.

After tack welding, the joints were meticulously aligned with some careful hammering, and then finish welded together, using .023-inch diameter ER 70-S6 filler wire to keep the welds small. Here I’m sanding the weld flush with the base metal, using a 50-grit abrasive disc on a right-angle pneumatic sander.

This is how the part looks with the welded areas sanded perfectly smooth. While it would certainly be possible to use plastic auto-body filler to smooth any irregularities, this part came out so well that no filler was needed.

I used 1/2-inch-diameter cold-rolled steel round bar for the legs. Hot-rolled bar could be used, but it requires more cleanup before painting. I’m using a Miller oxy-acetylene torch with a multi-orifice heating tip to make the bend in each leg.

I cut each leg slightly longer than needed, then trimmed the top ends to a consistent length after bending. Next, I made a careful layout on a piece of plywood to position the bottoms of each leg 120 degrees apart and spaced an equal distance from the center point. Then, by aligning the tops of each leg segment, I automatically got an arrangement that positioned the legs at the same angle and made the seat base level. This fixture greatly simplified the alignment of the legs.

Next, I made the footrests from 3/16 x 3/4-inch stock. I cut them to the proper length, matching the angle of the legs. I clamped the footrests into place, making sure that each element was level and a consistent distance from the ground. Once they were properly fitted, I tack welded each footrest into place.

I plasma cut a ring from 3/16-inch steel plate and sanded the edges smooth. This joins the tops of the legs and provides the attachment of the base to the sheet metal seat. I drilled holes in the ring for the #10 machine screws, which will fasten the seat to the base. I later countersunk these holes, so I could use flat-head screws.

Here I’m tack welding the legs to the ring. After double-checking all the angles and dimensions, I finish welded all the elements of the base. On joints like this, where the parts meet at an angle, the gun is positioned to keep the angle the same between both elements.

After painting, the legs and seat were joined with #10 flat-head screws, which fit flush, giving a very clean look.

And here is the finished stool — ready for many years of thinking and working.

Extra photo of the stool, in use.

About Ron Covell

Ron Covell is a talented welder and metalworker in the automotive industry. Covell is a contributor for Hot Rod Network, where he has a popular column titled, "Professor Hammer's Metalworking Tips." He also owns Covell Creative Metalworking, offers instructional metalworking DVDs and hosts workshops around the country. 

Welder and wife launch their own small business

Welder and wife launch their own small business

Side jobs making signs and metal art for friends turn into a new fabrication operation: Tough Weld Fabrication in Marysville, Mich.

Most metal fabricators like what they do. Charlie Penrod is no different.

In fact, he’s now established his own business, building on his love for making things. He got his first taste of metal fabricating when he went to work for a fab shop after being laid off during the Great Recession. He’s parlayed his newfound passion and work experience into Tough Weld Fabrication, which he and his wife, Amanda, opened in Marysville, Mich., in 2017. That’s where shoppers can find Charlie’s lawn art, signs, home decoration items, and sculptures. As the shop’s work has caught the eye of consumers in Marysville and the neighboring area, the Penrods also are taking on custom work, turning customers’ design ideas into art pieces.
Welder T-Shirt

Charlie does all the metal fabrication work himself. The workpieces are designed in a software program that creates the cut path for the shop’s plasma cutting machine. From there, the metal piece is finished to the customer’s specifications. That could include powder coating, painting, or just a simple polish of the metal surface.

Amanda said they hope to take on more production work by the fall.

“Our next business step is we’re actually going to expand the welding and fabricating side of things,” she said. “We’re also still going to have our little store, where everyone could still come in if they need to pay, look at paint color, or look at a type of metal.”

They’re expanding by opening a new fabricating shop in Port Huron, Mich., in November of this year. This new location is where they will complete industrial work, and it will give them the space needed to accommodate orders for sculptures, art, and custom signs.

The idea for the storefront started when they began designing and manufacturing signs for local customers for a variety of occasions, from a simple garden sign to wedding monograms. As they grew in popularity, the Penrods had to expand their business to accommodate the influx of orders.

While Tough Weld Fabrication mainly creates signs and sculptures, it is seeing an increase in other welding work, which is the reason the Penrods are expanding their commercial business. Amanda said Charlie worked on a recent project that called for one of the shop’s metal designs to be connected to a railing fabrication.

“We do pretty much anything that anyone can think of along those lines,” she said.

Like any fabrication company of any size, Tough Weld Fabrication is challenged in handling the amount of work orders it receives. Amanda said the small shop has been able to stay on top of all of the work, but sometimes complex jobs can prove to be a real stumper. For example, she received an order to cut out the profile of the Joker, Batman’s arch nemesis. Such a detailed cut-out was going to be too much to recreate in a sheet metal form, so the shop had to pass on that job.

Charlie does all the metal fabrication work himself. The workpieces are designed in a software program that creates the cut path for the shop’s plasma cutting machine. From there, the metal piece is finished to the customer’s specifications.

“So that was the only one that I had to turn down in more than a year,” she said.

Despite the occasional roadblock, Amanda said the new business has proven to be enjoyable because they are able to connect with the people in the community.

“There are so many people that you don’t see on a daily basis, and by doing this, we’ve got to meet so many great people,” she said. “The fun part is when you put so much work into a project, from beginning to end, and you begin to feel like you really know these customers because you’ve worked with them for so long on the project.”

Contributing Writer Kate Youdell worked as an intern for The FABRICATOR this summer.

3 drivers of welding throughput

3 drivers of welding throughput

Three principal drivers increase welding throughput in the modern shop: welding process advances, smart use of automation, and having the right information

Visiting a fab shop today versus 20 years ago would likely reveal significant changes in cutting and bending, with fewer machines and workers producing more parts than ever. In looking at the welding department, however, it may seem that not much has changed. The high-product-mix welding operation probably remains mostly manual with several welding robots at one end of the shop floor. Welding operators may seem to lay down beads just as they did before.

Or do they?
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A closer look reveals some subtle changes. Welding operators don’t spend as much time adjusting parameters, even though this shop processes a variety of materials, from stainless and aluminum to high-strength steels. They don’t produce many defective parts either.

At various places in the welding department, screens indicate what jobs are running where, and some show real-time welding data based on feedback from the welding power sources. This data can include arc-on times and other efficiency measurements like deposition rates, weld sequence, and component tracking

The welding department may also show evidence of lean manufacturing and other continuous improvements. Today’s welding operations often have welding fixtures and materials—clearly labeled and identified with inspection dates—prestaged and ready for the welding operator as soon as he or she finishes the previous job.

Welding robots are more prevalent and are no longer relegated just to high-volume production. In some cases, welding operators may be using flexible base plates that accept various fixtures and part orientations. It might not be surprising to see technicians programming and simulating a welding robot offline (see Figure 1). When a new job arrives at the welding robot cell, operators no longer have to run through routines with a teach pendant. Instead, they can load a program and use the teach pendant to provide reference points and programming touch- ups (see Figure 2).

These are just a few of the changes that may become apparent when looking at today’s welding environment. What hasn’t changed is the philosophy behind these improvements: Overall manufacturing cycle time drives a company’s profits. The less time it takes for an order to become a finished product, the more competitive a fabricator can be. To increase throughput, shops are scrutinizing every step in the quote-to-cash value chain, from sales and estimating to packaging and shipping.

Welder T-shirt

Many part-flow strategies in the welding department follow the lean principles used in other areas of the shop. But when it comes to welding technology, there is no one-size-fits-all method to increase throughput. Most strategies follow themes associated with three areas: welding process advancement, smart use of automation, and good information.

1. Process Advancements

Manual welding still dominates most high-mix, low-volume operations, and for good reason. An expert welder can adapt to new parts, overcome excessive-gap problems, and more. Still, the U.S. anticipates a shortage of approximately 400,000 skilled welding operators within the next five years, which poses a significant threat to manufacturing. Without these skilled employees, quality can suffer. At best, a bad weld can cost a company time, materials, and consumables. At worst, it can cost a company its reputation.

New welding technologies simplify and shorten training time, allow entry-level welding operators to complete more complex welds with quality results, and give skilled welding operators more efficient tools to support high productivity. Specifically, today’s technology is making it easier for welders of different skill levels to make good welds, even with changes in stick-out, gun angle, and travel speeds.

Figure 1 
Offline robot simulation and programming means the operator spends less time at the teach pendant.

Consider a modified short-circuit gas metal arc welding (GMAW) process that anticipates and controls each short circuit, then reduces the available welding current to create a consistent metal transfer. This precisely controlled metal transfer provides uniform droplets, creates only small ripples in the weld puddle, and produces a consistent tie-in to the side wall. Along with its ability to maintain the same arc length regardless of stick-out, the process makes it much easier for welders to control the puddle and learn to create uniform, quality welds.

Simplified user interfaces on welding power sources help take the guesswork out of programming the machine. Some even show full words and descriptions on digital displays, eliminating the potential for confusion over welding terminology, shorthand, and acronyms.

Additional technologies help shops tackle the challenges of welding new materials. Industry is demanding lighter, higher-strength materials that reduce weight and lower product and production costs. Various segments in the manufacturing sector such as heavy equipment are using high-strength steels ranging from 50- to 80-KSI tensile strength, while galvanized, 140-KSI-tensile, advanced high-strength steels are being used for some automotive chassis and reinforcement components. Many fabricators are processing more aluminum and stainless steel, as well as other nonferrous and more exotic materials, in their product designs.

Although many of these new materials improve the quality of the final products, they also pose new challenges in welding. Aluminum, for instance, has a natural oxide barrier on the substrate that, if not properly cleaned, can create lack of fusion within the weld. High-strength steels are generally more sensitive to cracking than mild steels. That creates the need to preheat or establish new weld methods to control heat. Galvanized coatings on thin steel sections protect against corrosion, but in welding they can cause more spatter as well as subsurface porosity. The chance for burn-through and distortion increases when welding thin materials too.

Dedicated welding systems for specific materials, as well as more advanced welding processes, help overcome these challenges. These include pulsed GMAW and synergic systems. Conventional spray transfer sends tiny droplets into the weld continuously, whereas pulsed GMAW is a modified spray transfer process in which the power source switches between a high peak current and a low background current between 30 and 400 times per second. During this switch, the peak current pinches off a droplet of wire and propels it to the weld joint. At the same time, the background current maintains the arc but has such a low heat input that metal transfer cannot occur. This action allows the weld puddle to freeze slightly to help prevent melt-through as well as minimize distortion and spatter. Such technology has proven effective in welding high-strength steels and galvanized steels.

Synergic systems—in which the power source, welding gun, and wire feed are in constant communication—address the needs of welding materials like aluminum. When the welder changes the wire feed speed, the pulsed GMAW system automatically adjusts other settings. As wire speed increases or decreases, the power level increases or decreases to maintain a constant welding arc, providing greater control for better weld quality.

2. Smart Use of Automation

When it comes to increasing throughput, welding automation may seem like the straightforward answer. Install a robot and it will weld all day, every day, reducing bottlenecks in the welding operation.

Of course, it’s not that straightforward, and it’s also not that uncommon to see an old welding robot sitting idle in the corner of a shop. Many times fabricators purchase welding robots to perform specific jobs, configuring them for one product or product family. Adapting the automation to other work in the future may not be so simple.

Today preconfigured weld cells allow companies to adapt systems to a range of applications and operation sizes. Operator training and engineering software programs simplify programming and the process of designing automation-ready parts, all of which make it easier to implement a robotic welding system.

Configured correctly, automation reduces cycle time by increasing arc-on time and deposition rates that deliver faster overall production, with less variability and improved quality. Additional benefits include less overwelding, improved first-pass weld quality, precision for complex welds or materials, less scrap and rework, and lower overall costs (see Figure 3).

Figure 2 
Flexible fixturing systems, combined with offline programming and simulation, help welding robots become more effective in high-product-mix environments.

With adaptable fixturing and offline programming, welding robots are now more flexible than ever. That doesn’t mean, however, that every job is a good fit for automation. For example, a robot may be able to access 90 percent of the welds of a certain subassembly. Does it make sense to reposition the part onto a second welding fixture where the robot can make the remaining welds, or take it to a manual welding station? Does repositioning the part cause quality issues? How easy is it for a manual welder to access the joints?

Whether automation works depends on the application, the material, and types of welds required. It’s important to ask the right questions to uncover the best, most efficient way to process the job.

3. The Right Information

Welding operators need to be productive, loading parts into the weld cell and laying down weld beads in a consistent manner. But the truth is, bottlenecks often remain. If that is the case, it’s important to pose a few questions:

• Are there quality problems upstream that are making welding operators’ jobs difficult?
• Are welding operators hunting for fixture components?
• Are they having trouble accessing the joint?
• Is better fixturing or workpiece positioning needed?
• Are there flaws in the weld procedures?

Companies may not know the answers to these questions without the right information, and in these cases, welding information management systems can help. These provide real-time data from the weld cell. They automatically collect and report arc starts, arc-on time, and quality performance based on amperage and voltage, among other factors. These systems can track how much time each welding operator spends welding, as well as how much filler metal he or she uses over a given period. Some also have built-in cost calculators that take into account the welding cycle time, filler metal usage, and shielding gas use.

Welding operators also can view 3-D models of what the final assembly is supposed to look like. With more visual information at their fingertips, employees are less likely to make common errors, like mixing up similar-looking components (mistaking a left-hand panel for a right-hand panel on symmetrical parts, for instance).

With these insights, companies can assess welding performance in real time and track both productivity and quality. They also can better identify trends and bottlenecks, potential operator training needs, and how to optimize welding production. In effect, these systems give shops an objective set of data that can serve as the foundation for improvement and increased welding throughput.

Figure 3 

Welding Project: How To Create a Bomber Seat Out of Steel

Welding Project: How To Create a Bomber Seat Out of Steel

Custom built

Bomber seats have been used in racing cars for many years. The term comes from the days when military surplus aircraft seats were fitted into competition cars to save weight. Now there is a trend for many traditional-style cars to use “bomber” seats, and these days most of them are custom-built since the supply of military surplus seats has largely dried up. True bomber seats were made from thin, high-strength aluminum, and they were usually riveted together. While everyone likes the look of rivets, making a complex riveted structure takes an inordinate amount of precision and time.

I wanted to make a bomber seat using an easier process, so I designed a seat with the sides, bottom and back made from a single piece of metal. I added a simple reinforcement to the edge — which also gives the seat a more finished appearance. I made my seat from steel, so the joints could be easily spot or plug welded with a machine like the Multimatic® 215.

 Welder T-Shirt

The first step was making some models from paper, working out the shape and proportions I desired. Once I finalized the design, it was simple to scale up the dimensions and do a full-sized layout.

I made a bending fixture from some scrap tubing and plate. Laying out bends can be challenging, but I devised a simple system. Rather than trying to position and clamp a piece of tubing onto sheet metal for making the bends, I placed a stop on the tube that registers the edge of the sheet metal. This makes it easy to make consistent bends, even when some are angled, like the seat back. I positioned the stop to create a 3-inch flat flange, and the tube gives a 2-inch- radius curve. If you bend the metal to 90 degrees, each side draws in 2-¼ inches, so to get a 16-inch-wide seat, I start with a blank 20-½ inches-wide.
 Welder T-Shirt

Aircraft seats are often riddled with holes to reduce weight, and I really like this look. I decided to use oval punches for this seat, with a staggered pattern, and I spaced the holes as close as the tooling would allow. I used a J-shaped strip of metal to reinforce the edges and to cover the raw metal edge. I spot welded everything together, but the joints could be plug welded, too.

Plug welding is easily accomplished with a MIG welder or multiprocess welder, like the Multimatic 215. Once you decide where to place the welds, a hole is drilled or punched through one thickness of metal — I normally use a 5/16-inch-diameter hole for this. Next, the overlapped panels are clamped tightly together, and a weld bead is run around the edge of the hole, adding filler wire until the hole is plugged completely. Done correctly, this makes a low-profile weld, with excellent strength and very little distortion. If desired, you can sand the weld flat, making it completely invisible.

Scroll through the photos, and I’ll describe each step in the process.

I made several miniature paper mock-ups to work out the seat’s proportions.

With the design finalized, the dimensions were scaled up and transferred to a sheet of steel, including the layout for the lightening holes.

I used aircraft shears to trim the blank to size. You’ll see how important the round holes are when we make the bend between the seat bottom and back.

I’m using a beading machine to roll a step in the metal, which will make the joint flush on the inside.

I’m making a test bend in the fixture. A key feature is the stop which registers the edge of the metal (at the tip of the arrow). This ensures that all bends are the same, and it eliminates the need to move and re-clamp the fixture. With this system, the bends are positioned by the edges of the blank.

The sides of the seat bottom are parallel, but the back tapers. This is easily accomplished by bending the flanges on each segment individually.

The bend between the bottom and the back is done freehand, but it’s constrained to the area between the round relief holes in the blank.

Pins are used to align the male and female parts for the oval hole punches. Here I’m using a annular cutter to make the holes for these guide pins.

I’m using an H-frame hydraulic press with the Jamey Jordan ‘Oval Punch and Flare’ dies. These punch the hole and flare the edges in one operation.

The flush-fitted lap joints are now spot welded together.

Plug welding is another good option for making joints like this. I’m using the Auto-Set™ feature of the Multimatic 215 mutliprocess welder to get the parameters dialed in, based on the wire size and metal thickness.

To make plug welds, I punch 5/16-inch diameter holes, clamp the panels together, and then run a bead around the perimeter of the hole, adding filler metal until the hole is filled. Plug welds are fast and strong, and they offer just as much strength as a spot weld.

Now the cut line is marked for the seat sides, and they are rough-trimmed with a cordless shear. This rough trimming could also be done with a plasma cutter.

The final trimming is done with aircraft shears.

I used a sheet metal brake to bend a sharp angle in a piece of sheet metal, and then used flattening dies in the beading machine to roll the flange over to 180-degrees. This will be the cap strip for the seat edges.

The edge cap needs to be curved, and I’ve made a paper pattern to follow as I do the shaping.

The edge cap is curved by working the long flange with a shrinker and stretcher.

After the cap has been properly contoured, it needs a twist in the top corners. I’ve clamped the cap to my versatile bending fixture, and I’m hammering it around the tube to get the twist.

With the cap fitted, the ends are spot welded into place.

Here I’m using flattening dies on the beading machine to tightly crimp the edge cap to the seat.

Here’s the finished seat, and I’m delighted with the way it came out! Making the seat from a single piece of metal, and spot welding the joints really eased the construction. A seat like this can be made in a fraction of the time it would take to make a riveted aluminum bomber seat.

 

About Ron Covell

Ron Covell is a talented welder and metalworker in the automotive industry. Covell is a contributor for Hot Rod Network, where he has a popular column titled, "Professor Hammer's Metalworking Tips." He also owns Covell Creative Metalworking, offers instructional metalworking DVDs and hosts workshops around the country.