• Fabrication, Welding and Alloy Wheel Repairs in Wiltshire and surrounding areas

How to Fix An Alloy Wheel Crack?

Something Doesn’t Feel Right …

Here at Webb Welding, we do come across our clients mentioning that they feel a vibration in their seat, steering shaking or the tyres are consistently loosing air. However, this could mean a whole bunch of things, perhaps the wheel is out of balance, could be a bad valve stem or your tyres simply have a hole. On closer inspection, you identify that the problem is occuring directly from the wheel itself.

We have inserted a picture of an alloy wheel below, fairly common on most modern cars today. They are very sturdy but if you drive through a large pothole, you can often bend the wheel. Initially, you will not be able to know what the problem is but you will certainly feel it. Sometimes, you can bend or crack the rim. We offer a service here at Webb Welding where we can straighten the wheel, carve it back to a perfectly round shape and we can also weld the crack.

Identify the Crack

Sometimes the crack can go all the way over the edge and right across the rim and we use a specialised type of remedy called tig welding. If you opt for anything else, the repairs will not last and the already weak wheel will crack again.

So, we will begin the process by prepping the wheel, then tig weld it, make sure that it’s true and round and place it back to factory specifications. We begin by removing all the factory paint and take it back by grinding it down to bare aluminium. The weld is prepped and gouged for true and proper penetration for both inside and out.

A Quote by Benjamin Franklin: “By Failing to Prepare, You Are Preparing to Fail”

Preparation is everything. The prep must go beyond the crack to relieve any pressure and secure its strength when its welded. The crack is now completely gone and secured and we also sand it down till it’s smooth. It is absolutely essential that the prepping must cover both sides, and then we proceed to weld it. On completion of the welding, we will ensure the wheel’s shape is restored.

Then, we meticulously check to see if the wheel is round and not square. Just kidding …

There you have it, one fixed alloy wheel with complete reassurance.

How to Fix An Alloy Wheel?



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5 steps to get the most out of scrap metal

Manufacturers generate scrap during the production process. This scrap is collected and sold to scrap companies to be processed and then sold to the mill, which will eventually sell the new steel back to those same manufacturers. That’s the life cycle.

For the longest time industrial recycling has been handled the same way: You call a few scrap companies, obtain pricing, have the selected provider place a few containers, fill the containers, and wait for the payment. You hope the check comes. When it does, you match the payment you received with the weight and type of commodity your company placed in the containers and the corresponding dollar amount.

Nothing new here yet, so why keep reading? Here’s why. Manufacturers make money on their products, and everything else in the process is a cost center. Right? Almost. Scrap is not a cost center; it’s a profit center. It’s a byproduct of the process and probably the only revenue generator a manufacturer has besides the products it makes.

For this reason, it is worth paying close attention to and maximizing these revenues. Decision-makers have different reasons for selecting scrap companies, whether it’s price, service, existing relationships, transparency, accountability … or even tickets for seats behind the dugout.

At one point most scrapyards were mom-and-pop businesses. Some were honest and well-run, while others knew every trick to separate manufacturers from their scrap and pay the least possible for it. Today many large, publicly traded companies have entered the market and have added a level of honesty. That said, even the honest ones want to buy low and sell high—and who can blame them? Like everyone else, they’re in business to make money.

Scrap buyers need to be competitive. They don’t want others to swoop in, offer a little more, and win your business. At the same time, they also work to ensure they end up with healthy margins.

Considering all this, how can you get the most out of your scrap? That depends on the type, variety, volume, and condition of your scrap material. And it can take a lot of time, knowledge, and experience, in which case outsourcing your scrap management can sometimes make business sense. That said, no matter who handles your scrap revenue stream, they should follow a few fundamental steps.

1. Tie the Negotiated Price to an Index

If you’re a fabricator, you produce scrap every time the punch press or laser cutting machine finishes a nest. Selling it isn’t a one-time event. If you just shop around for the best price, you might have a scrap company lure you in with an above-market price, then ever so gradually lower your per-ton rate to a below-market price.

Scrap companies will be slow to react to up-markets and quick to react to down-markets. But the price itself shouldn’t come out of thin air. From the start, you need to ensure pricing is tied to a defined commodity-market index so that you protect yourself when the market falls and benefit when the market rises.

The index price generally will not be the same as the agreed-upon price for the scrap. When negotiating your scrap prices, you’re really negotiating the price differential—that is, the difference between the market index price and the amount the scrap company gives you. When your scrap prices are tied to the market index, they should move in lockstep with it. When the index goes up $20, your scrap price should go up by the same amount.

2. Reverse-engineer the Price Differential

When negotiating the price differential, try reverse-engineering it; that is, factor in what has to happen to the scrap before it’s sent to the mill, including the shipping and processing costs, as well as what the mills in the area are demanding. This gives the whole process a level of transparency.

Consider a pallet of sheet metal skeletons fresh off a laser cutting machine. These skeletons must undergo a number of value-adding steps before a mill will buy them. They need to be segregated by type and cut down to a mill-acceptable size, such as a 3- by 3-foot section.

Preparation steps depend on your exact material mix and specific mill requirements in the area. That said, if you map the basic steps, you can then assign cost estimates to them. This allows you to start with the index and factor in those costs, as well as transportation costs, to “back in” to a fair price—one that covers costs, gives you a competitive rate, and gives the scrap company a reasonable margin.

With all this, you can develop a pricing structure. It boils down to knowing where the material is being sold (that is, what mills are buying the scrap), as well as its cost to ship and process, then incorporating a handling fee and a little profit for the effort.

Knowing all the value-adding steps involved in the scrap business also can help you decide whether it makes business sense to perform some scrap prep on your own floor. For instance, would it make sense to chop your sheet skeletons? In a sheet metal or plate operation, you probably wouldn’t want to tie up a laser or plasma to cut up a skeleton. But if you have idle hands and torches available, they could be put to good use. Cutting skeletons does take time, of course, so whether this makes business sense depends on your own processes and the price increase a scrap company is willing to give you.

That said, your company, wanting to focus solely on producing products for customers, might just perform the least amount of scrap prep possible. And this can sometimes make sense; scrap prep can add another ingredient of complexity on an already complex shop floor operation. But remember that, like the parts you produce, scrap is also a revenue center, so it’s often worth scrutinizing to get the most out of it.

3. Stay on Top of Your Load and Tracking Reports

Every day a truck arrives at your facility, retrieves your scrap, and leaves a pickup receipt and scale ticket (showing the amount weighed at the scrap company’s facility) at your dock. At the end of a certain period, the dock foreman retrieves the scale tickets and delivers them to the front office.

When a check from the scrap company arrives at the end of the month, somebody in the office needs to verify how many loads left the facility and how many loads the company got paid for. Often, not all of those pickup receipts make it into the office. And sometimes the scale tickets don’t match what’s itemized on the check from the scrap company.

Who’s responsible for matching the pickup receipts to scale tickets and verifying each load is accounted for? If you work at a busy plant, you need someone overseeing this process, especially if you scrap aluminum, stainless, or other high-value commodities. This is critical. Each load or misload can account for thousands of dollars.

4. Look out for Downgrades

It happens. Two skeletons of ferrous material find their way into a bin of nonferrous scrap. This turns a “clean load” of stainless into a “dirty load.”

The same thing applies to the form of scrap, be it chips and turnings or solid pieces of scrap. Perhaps you have a machining department near your sheet metal operations. Maybe the main fork truck operator is sick and his replacement dumps turnings into a box dedicated for solid scrap. Boom, you get $150 per ton instead of $250 a ton. Even though 98 percent of the weight is solid, the entire load is downgraded.

Beware—that’s just how the industry works. It’s common industry practice to pay for the least valuable commodity in a load. If a dirty load is 90 percent stainless and 10 percent another, less expensive material grade, you don’t want the entire load to be downgraded to the lower price. Ideally, the payment should be based on the percent of material in a load.

Some form of downgrading for dirty loads of scrap is certainly fair, particularly if a dirty load significantly increases the amount of segregation work. But it doesn’t take too long for a scrapyard worker to lift one skeleton of ferrous material out of an otherwise clean load of stainless. And again, one ferrous skeleton shouldn’t downgrade the entire load.

If a scrap company does downgrade a load, it should provide documentation showing why it did so. Most scrap companies can take pictures and provide documents explaining why and exactly how they downgraded the scrap. Make sure there is an agreement in place to send documentation and pictures for any downgraded load. This also will help you contest future downgrades down the line.

Just having the conversation about these kinds of details can help build a relationship. If you talk with the scrap company about how it handles dirty loads, you build an understanding of how it operates. This in turn builds mutual respect with an understanding that documentation is part of a modern, “trust-but-verify” business relationship.

5. Request Third-party Weight Verification

This is another part of that trust-but-verify relationship. Several times a month, request to see a loaded truck’s weight reading from a public scale, like a CAT scale between your plant and the scrapyard.

Ideally, you should be able to request these third-party verifications randomly. The CAT scale report should have a time stamp and a recorded weight; the scrap company then should have a separate scale report with a slightly later time stamp and (ideally) nearly the same recorded weight, within a certain range or tolerance window.

Again, the scrap business has evolved, so you don’t have the “not all four wheels on the scale” kind of games seen in decades past. Scrap companies these days usually operate to a certain standard. Regardless, to get the most out your scrap, it’s just good business practice to request documentation.

From an Afterthought to a Profit Center

So where do you go from here? First, know that not all scrappers are created equal. Some have better markets than others for ferrous and nonferrous. Figure out which are which, and source the ones that best represent the commodities your company is scrapping.

Next, figure out if they currently are using a formula or a differential to an index. If so, great. If not, find out what the scrap company’s average prices for the past year were.

Finally, hit the markets. Get pricing for every single commodity generated and compare it to the others. For peace of mind, benchmark all of these to an index.

It’s not rocket science, but it does take someone to track and oversee the process. That person should understand scrap and how it’s traded and negotiated. Also, be sure to add protocols for your team and scrap company so the scrap process is done properly. When and how should the scrap bins be filled, and by whom? If the usual fork truck driver is sick, who will manage, transport, and sort scrap until he returns?

The goal is to monitor and maximize every aspect of your scrap program. Done right, you can turn scrap—an afterthought for most manufacturers—into an increasingly valuable profit center.

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Understanding aluminum welding compared to steel welding

Welding aluminum presents some unique challenges compared to welding steel or other common materials, particularly in terms of the chemistry and crack sensitivity.

In many cases, welding aluminum requires following some special procedures. Important factors when welding the material include: selecting the right filler metal; proper storage and thorough cleaning of the base material; and proper welding techniques.

Here are some common challenges when welding aluminum and key best practices for addressing them.

Characteristics of Aluminum

A sound weld is all about chemistry, reduction of hydrocarbons, and proper technique. The characteristics of aluminum differ from steel in several ways. The melting point of aluminum is much lower than that of steel — 1,221 degrees Fahrenheit for aluminum, compared to 2,500 degrees for steel. Aluminum also has an oxide layer that melts at approximately 3,700 degrees. This oxide layer is much harder than the aluminum and helps the material resist corrosion and abrasion. However, it also acts as an insulator that can create issues during welding.

Because the strength of aluminum tends to increase as service temperature decreases — unlike steel, which becomes more brittle as service temperatures decrease — aluminum is commonly used in cold temperature applications, such as cryogenics and liquid natural gas transportation.

While iron is a main alloy in steel, aluminum materials are mainly aluminum with the addition of a variety of elements.

Wrought alloys, like 1xxx series aluminum, are pure aluminum with no alloying elements intentionally added. The principal alloying elements in other types of aluminum are copper in 2xxx series, manganese in 3xxx series, silicon in 4xxx series, magnesium in 5xxx series, magnesium and silicon in 6xxx, zinc in 7xxx series, and other elements in 8xxx series.

Challenges of Welding Aluminum

The different characteristics of aluminum become apparent during the welding process. Thermal conductivity and issues with porosity are the two biggest differences in welding aluminum compared to steel.

Hydrogen is very soluble in liquid aluminum. As the filler material and aluminum base metal become liquid during the welding process, they absorb hydrogen and can hold it in solution. Once the molten material starts to solidify, it can’t hold the hydrogen in a homogenous mixture anymore. The hydrogen forms bubbles that become trapped in the metal, leading to porosity.

A helium/argon shielding gas mixture can be used to combat porosity issues if all other options have been tried. Be aware that with a helium mixture, voltage must be increased to overcome the higher ionization potential of this gas compared to argon. The increased voltage will cause higher heat input and additional penetration, which is why this mixture is used on thicker aluminum base materials.

Unlike with steel, the presence of hydrogen does not cause cracking in aluminum welds. However, hot cracking, which can occur as the weld solidifies, is a threat with aluminum. The solution for this comes back to chemistry. If hot cracking is an issue, refer to an aluminum filler metal selection chart to find the filler metal that best addresses this problem.

A 6061-aluminum base metal is an example of a material that is in the peak crack susceptibility at its current chemistry, making it very difficult to weld autogenously or with a similar chemistry filler material. Using a filler metal with elements such as magnesium (ER5XXX) or silicon (ER4XXX) can help push the material outside the crack-susceptible range.

Another challenge with aluminum is that it is five times more thermally conductive than steel. The cool areas of the base metal try to pull heat away from the weld pool, which can cause a lack of penetration in the weld. Because of this difference in thermal conductivity, aluminum requires much higher heat inputs than steel during welding.

Choosing a Filler Metal

It’s critical to use a selection chart when choosing a filler metal for aluminum. Each combination of aluminum designations has recommended filler metal options, depending on the weld characteristics required by the application.

A selection chart includes eight characteristics that are important in various welding applications: crack sensitivity, strength, ductility, corrosion resistance, elevated temperature service, color match after anodizing, post-weld heat treatment, and toughness. By analyzing the needs of the end component, it is possible to determine which properties are most important in the specific application and to select a filler metal that best matches the characteristics required. It is important to note that elevated service temperature with aluminum is 150 degrees to 350 degrees Fahrenheit. This and other definitions of the characteristics can be found on the aluminum selection chart.

Another option is to use a filler metal selector app, such as this one. The same information that is on the full selection chart can be found in the app, but it shows filler metal for the selected base materials only.

Proper filler metal selection is always key. For example, if the base material being welded is 6061 aluminum, good filler metal options include 4043, 4943, and 5356. A 4043/4943 gas metal arc welding (GMAW) wire or gas tungsten arc welding rod can reduce porosity and provide better weldability and increased puddle fluidity, while a 5356 product provides greater toughness and strength.

Best Practices

Along with choosing the filler metal best suited for the application, following some key best practices also can help achieve success when welding aluminum.

    • Don’t weave. While a weave technique commonly is used to weld steel, it should not be used with aluminum. Instead, use a stringer bead, which helps ensure proper penetration and fusion. For aluminum GMAW, be sure to use higher heat inputs and a fast travel speed to stay in front of the puddle.


    • Clean the metal. Thoroughly clean the base material before welding to remove oil, dirt, residue, and moisture. This helps ensure the best results and reduces chances of porosity. An acetone or aluminum cleaner works well for removing hydrocarbons that may be on the material surface. When prepping the weld joints, don’t blow them off with compressed air, as this can introduce contamination from moisture and oils if shop tools are used.


    • Remove the oxide layer. After cleaning, use a stainless-steel brush — one that is new or has been used only on aluminum — to remove the aluminum oxide layer before welding. As mentioned previously, aluminum oxide has a much higher melting point than aluminum. It acts as an insulator that can cause arc start problems and very high heat is required to weld through the oxide layer. This can cause burn-through on the base material and porosity, since the oxide layer tends to hold moisture.


    • Store it properly. Storage practices for base materials and filler metals also play a role in preventing porosity. Store sheets of aluminum inside when possible. If they must be stored outdoors, stand the sheets vertically rather than on top of each other to prevent trapping water, which will contribute to the formation of a thicker hydrated aluminum-oxide layer. For materials and filler metals stored outside or in an air-conditioned part of the building, bring them inside to the shop before welding—preferably the day before—to let the metal temperature stabilize and help prevent moisture in the air from creating condensation on the aluminum.


    • Check the consumables. Some issues with aluminum welding—especially when using GMAW— can stem from the consumables. To help reduce the risk of porosity, use gas lines and hoses that are new or in good condition and make sure all hose connects are tight, so they’re not pulling air into the line.It’s also important to use the proper liners and drive rolls. Plastic liners and inlet guides can provide benefits over steel liners in aluminum welding because the metal or brass inlet guides and steel liners can abrade the softer aluminum wire as it travels through the drive system and liner. This can result in wire shavings that clog the liner and cause feeding issues. Similarly, U-groove drive rolls are standard for aluminum applications because other types of drive rolls can smash or distort the wire.


  • Monitor the temperatures. Consult an aluminum filler metal guide or code to determine the appropriate preheating and interpass temperature ranges. Preheating can be used to reduce the thermal effects of section size when welding thick base metals or dissimilar thicknesses, but keep preheating to a minimum for aluminum applications.Heat-treatable base metals and 5xxx series base metals containing more than 3 percent magnesium should not be subjected to preheating or interpass temperatures above 250 degrees Fahrenheit for more than 15 minutes. Time spent at elevated temperatures can reduce the strength of the material and contribute to cracking.

Achieving Success

Addressing the challenges of welding aluminum often comes down to chemistry. Making the right base material and filler metal match goes a long way toward achieving success and minimizing issues. It’s also important to follow recommended best practices for welding aluminum. And remember, the techniques and best practices for welding aluminum are very different than those for welding steel.

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