Month: January 2022

The Stages of Preparing Sheet Metal for Finishing

You’ve found yourself working on a project that requires finished sheet metal to complete, and you're not sure where to begin. If you're used to working with pre-finished sheet metal or previously outsourced this step of the process, you might be wondering how much time it will take. How is applying finish going to alter your projected schedule?

You can't just apply the finish and call it good. The steps you must take beforehand are labor-intensive and require specialized chemicals to do correctly. But the good news is, it doesn't take much time at all. 

We wanted to break down the metal finishing process for people like you with this blog post. Once you know how to prepare sheet metal for finishing, you'll work more efficiently and be able to tackle a broader range of projects. So keep reading to add this valuable skill to your toolbelt. 

Step 1

Prepare Areas to Be Finished 

Depending on your project, not finishing your sheet metal may have an uneven appearance. For example, paint won't properly adhere to some aluminum. You can save yourself some time (and finish!) by covering any sections you can't apply it to with tape.

What tape you use mostly comes down to personal preference. However, for the sake of comparison, here's a comparison of the types most commonly used in construction projects:

Masking Tape: This tape is suitable for masking smaller surfaces because it leaves less sticky residue behind than other types of masking tapes. The only downside is that it can leave a small amount of residue depending on what type of sandpaper or steel wool you're using for sanding.

Duct Tape: Though generally used for home repairs and such, it's another excellent choice for protecting metal. However, the adhesive will leave some residue that you could either sand off or use chemicals to remove.

Painters Tape: Painters tape is great because it shouldn't leave any residue behind, and it sticks well to multiple surfaces. The only downside is that it can start to peel off if left for too long, so you should apply it at least twenty-four hours before you intend to begin the preparation process.

Step 2

Cleaning the Metal 

Once you've protected any parts that don't require a finish, it's time to start cleaning. When it comes to finishing sheet metal, cleaning is a vital step that you cannot afford to do by half-measures. If you don't clean the surface appropriately, your finish won't adhere, and you'll have to repeat the process.

You cannot simply eyeball the metal to confirm that it's clean. Even small debris, like sand and dust, will result in noticeable spots later on. What's more, grease can remain on sheet metal from its manufacturing process.

A good deep clean starts with degreasing agents, which come in wet and dry forms. Both are effective, varying only in how you use them, so be sure to follow their instructions carefully. And don't forget to wear appropriate safety equipment when handling these chemicals! 

Next, completely remove the degreaser from the metal. Any that remains will prevent the finish from fully adhering to the metal. Wash with a mild detergent and thoroughly dry.

Step 3

Remove Impurities

Your sheet metal likely contains impurities from the manufacturing process. Shortly after pressing, each sheet is dipped in a metal pickling solution to remove them. However, pickling often creates new impurities, albeit in a lesser amount.

It's best to play it safe and sand down the exposed sheet metal, just to be sure. Start by scrubbing all sides with 150 grit sandpaper and smoothing out all rough edges. When finished with this step, wipe down your sheet metal one more time before applying any finish.

Optional Step: Start Again 

It can be difficult to detect every impurity still on your metal. So rather than fretting over each step until you're absolutely certain, another approach is to simply run through steps two and three again before moving on. This method removes doubt by giving you visual evidence of debris reduction.

Every time you clean and remove impurities from your metal, you'll notice less dirt and debris gets removed each time. Using this as a guide, you can repeat the process until you're satisfied. However, keep in mind that sanding too much will wear down the metal, so work towards satisfaction rather than perfection.

Step 4

Apply Your Finish 

At long last, it's time for the finish. But, don't skip out on the safety equipment! These chemicals are safe for metal but are harmful if they contact exposed skin.

Apply a small amount of your finish over the sheet metal until it is fully saturated. Let it rest for at least twenty-four hours or until it has completely dried. Afterward, grab some steel wool and start scrubbing until your metal has a shiny appearance.

All you have to do is remove the tape from the first step, and that's it: you're ready to apply paint over the finish and use the metal as needed. All told, it shouldn't take longer than two days to successfully prep your sheet metal for finishing.

Learn More About Metal Prep With Engineered Mechanical Solutions

Learning to prep sheet metal will help make you and your team more self-sufficient, saving time and money. But some procedures are too specialized to tackle on your own. When it comes to manufacturing services, you need a partner with experience. 

That's why we're here.

Since 1990 our team at Engineered Mechanical Systems has provided project managers with custom fabrication and machining solutions. We've equipped our facility with the latest industry-standard machinery, but more importantly, our staff of passionate and experienced professionals. We're here to help you to get the right solutions every time.

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Tips You Need to Know for Welding Aluminum

Welding can be a challenging task even for the most experienced welders. Not only does welding aluminum require different techniques and tricks than welding steels, it's a skill needed to complete a variety of different projects.

Despite it's difficulty, there are tips and tricks you can keep in mind to develop your skills with aluminum welding. With the right knowledge and enough practice, anyone can weld aluminum.

Keep reading to learn about how you can weld aluminum- from tips and tricks for success to the different techniques you can try out for yourself.

What Makes Aluminum Welding Difficult

Aluminum is an extremely common metal in the fabrication industry. It doesn't corrode over time, it shines in the lights, and it's lightweight.

Despite these things making aluminum desirable, these same things make it very difficult to weld. Aluminum is very soft and sensitive to outside factors. When it's molten, it can be susceptible to various forms of impurities.

For you, that means a porous and weak weld that won't stand up to the test of time.

In addition, aluminum has a layer of aluminum oxide on the outside of it, which melts at a much higher temperature than the rest of the aluminum inside of it. It requires high heat to burn through it, but control over that heat. If you burn too hot too quickly, it'll burn holes into the pure aluminum layer underneath.

Aluminum can be contaminated by the air itself due to poor shielding or excessively long arcs. Oxygen can reduce how strong the aluminum is and its ductility.

Finally, if you're working in a humid area, hydrogen can be introduced to the environment and create air bubbles throughout the cooled aluminum. This can happen if the weld joints are damp as well.

All of these issues aside, there are ways you, as an experienced welder, can avoid these common pitfalls.

Benefits of Using Aluminum

Despite the difficulties that come with using aluminum, it is extremely beneficial in many applications. It's lightweight and has a great strength-to-weight ratio in comparison to many other metals. That means it gets stronger instead of brittle when the temperature goes down. On projects that need to be strong yet light, aluminum is a great choice.

Aluminum also is recyclable and absorbs paint and sealant, so it's often chosen for its global footprint and its aesthetic appearance.

Finally, aluminum is able to conduct electricity and heat almost as well as other more commonly-used metals like copper and is completely non-corrosive.

Wear The Right Protection

When you weld any kind of material, you're exposing yourself to high heat and plenty of danger. You need to always wear the correct personal protective equipment (PPE) when working and educate yourself in every safety procedure possible.

This means understanding the nearest fire escapes, understanding where to go in case of equipment malfunction, and understanding your efforts in preserving your safety means a long and successful career in the industry.

Avoiding Impurities and Hydrogen Bubbles

This may be one of the easier things to solve when working with aluminum. Impurities are introduced to aluminum through messy work environments and unclean aluminum.

Use a solvent like acetone to remove oil, grease, and water vapor from the aluminum's surface before working with it to ensure it's clean.

Ensure your aluminum is fully dry before working with it, and ensure that it's free of any and all moisture particles. Once you've done that, you've reduced the likelihood of weakening your weld and have decreased your chances of seeing hydrogen bubbles in your final weld.

Breaking The Alloy Layer

Ensuring an even melt might be the trickiest thing to do. You have to be in complete control of the temperature at all times to ensure you get the perfect finished product. Hot enough to go through the alloy later but cool enough not to burn the pure aluminum beneath.

This will take practice, but there's a few things you can do to help. Before working with your aluminum, use a stainless steel wire brush that you only ever use on aluminum to remove oxides from the surface. Then, wash and dry the part thoroughly.

Doing this will provide you with an easier time in handling the aluminum and help it heat more evenly, giving you a neater final product.

What Methods Work?

Theoretically, you can use stick welding methods, GTAW/TIG methods, and GMAW/MIG methods when working with aluminum. It is, however, not very common to use stick welding techniques.

This is because stick welding can be extremely messy when working with aluminum.

However, it could be advantageous to use this method when working with rusted or painted metal pieces because it can allow you to work without a shielding gas.

Gas Tungsten Arc Welding (GTAW)

This method is also known as tungsten inert gas (TIG) welding, and it's the most common method chosen by professionals when working with aluminum. It's common in the automotive industry and is often seen as a welding technique for professional racing teams.

This method requires a consistent current with alternating current capabilities. It uses 100% argon as a shielding gas. It doesn't use any mechanical wire feeding; instead, you, as the welder, feed filler material into a puddle.

It's much cleaner than the stick welding method because the alternating current cleans the oxidized layer off the aluminum as it welds it together.

It also aids in preventing contamination, which, as we've gone over, is an extremely common problem when working with aluminum.

Gas Metal Arc Welding (GMAW)

GMAW, commonly called metal inert gas (MIG) welding, is another method commonly used when welding aluminum.

This technique can often be completed much quicker than other methods and has higher deposition rates than TIG welding.

However, it does have a mechanical wire feeding system, which means you have to use a push-pull gun or a spool gun to make wire feeding possible. This means more tools and items for you to keep track of when welding.

To combat the aluminum from experiencing problems with porousness, you must make sure the base material and filler rod are clean, moisture-free, and have excellent shielding gas coverage.

What If I Want Something Different?

There are a variety of different techniques you can use instead of TIG, MIG, and Stick Welding techniques when working with aluminum.

You could try laser beam and electron beam techniques, which use precise heat zones that are easily controlled by the welder to make a clean and fast weld. It's great for materials that crack easy like aluminum, but it requires specialized machinery you may not have access to.

You could try resistance welding, but you must keep in mind the high thermal and electoral conductivity of aluminum while you work. While it can work, it's not an advised or common method.

You could try shielded metal arc welding (SMAW) methods, but it's not recommended by our team. You might be able to repair cast aluminum with this method, but it oftentimes produces lackluster results.

What To Avoid

Understand that when you're working with aluminum, you must always be flexible. There is never one perfect solution when working on a project that requires aluminum welding. You need to use your knowledge and skills to find the best solution for that project and trust in your own ability to do it right.

You shouldn't base your technique and experience on your previous work with other materials, either. Working with aluminum is very different than working with any other metal, and it requires its own unique skillset.

You must always be prepared for the worst with aluminum as well. Ensure you have the proper tools and solvents to clean and store aluminum without worrying about water vapor, and ensure you are beginning your weld by minimizing as many negative factors as possible.

Finally, details are everything. The smallest mistake can mean you ruin an entire aluminum welding project. Double-check your work to ensure you haven't forgotten any preventative measures to ensure the best weld possible.

If you want to learn more about metalworking and manufacturing, sign up for our newsletter to learn all about the ever-changing world of manufacturing. 

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What’s the Range of Laser Cutting Machines?

Laser cutters create patterns and designs by cutting into materials with a laser beam that melts, burns, or vaporizes the material it's being applied to.

In short, a thin laser beam etches and cuts materials. It can be programmed to produce custom designs, patterns, and shapes per the designer's requests.

Since the process is thermal-based, materials such as wood, glass, paper, metal, plastic, and gemstone are great candidates to be cut or engraved with a laser cutter.

There are multiple kinds of laser cutters, and each can accomplish different things. To help you decide which laser cutter is best for your business, keep reading to see the entire range of laser cutters available on the market.

History of Laser Cutters

C. Kumar N. Patel invented the laser cutter in 1963 when he developed the first CO2 laser. This laser now has the most modern applications over any other kind of laser on the market.

Kinds of Laser Cutters

There are two primary kinds of laser cutters on the market —  CO2 lasers and fiber lasers.

CO2 lasers can have a more focused and intense beam, amplifying the cutting power. This might be the best place to go for cutting through, especially touch materials.

CO2 lasers carry potential danger from reflective metals like copper, brass, bronze, and stainless steel. There's a risk of the material reflecting the laser and causing damage to nearby production or the laser reflecting directly back into the machine. Since these reflective materials are pretty common on assembly lines, opting for a fiber laser may be the best option for safety.

Fiber lasers offer a lower risk for this kind of damage as it is designed to reduce the risk of unwanted reflection. These machines are often lower-maintenance and allow production teams to spend more time turning around projects rather than focusing on repairs.

What To Consider When Buying

When you're in the market for a new laser cutter, there are various things for you to consider.

First is whether or not your machine can complete the project you're buying it to complete. If you need to design custom parts out of heavier materials for a machine quickly and effectively, a CO2 machine may be your best option as it will effortlessly work through tricky materials.

If you're looking for a machine that can handle many materials with little risk of reflection damage, then you may want to consider a fiber machine.

Finally, where do you want this machine to be? If you're looking for a desktop machine to have at home to work on smaller projects, you'll want a vastly different machine than someone looking for the perfect piece to complete an assembly line.

We've compiled a list of some machines for you to consider for your next laser cutter purchase.

Best CO2 Budget Pick: OMTech 40 W (DF0812-40BG)

MTech imports this machine into the US, where they complete enhanced quality control checks before selling to a US market. Since OMTech itself operates out of the US, there are more customer service options than if you were to import a K40-Style laser directly from Orion Motor Tech in China.

This is a combination engraver and cutter. It's a great model as an entry into the world of laser cutting, but home-use, it's a great way to experiment with the medium and see if you should invest in a more expensive and luxurious machine.

Since this machine will cost around $500, it's still an investment and more expensive than in previous years. Still, it's a reliable machine that will ensure you can experiment with cutting coated metal, rubber, wood, and leather. It cuts 2-3 mm deep, which gives you flexibility with the projects you take on.

The Can-Do-It All: Glowforge Plus

Glowforge Plus is a CO2 laser-type and provides a precision of up to .025 mm. This is a machine optimized for home and office use but can also handle heavy-duty projects.

Unlike many other machines, this one can handle glass, acrylic, fabric, and cardboard and cut up to 12mm deep. While this machine isn't cheap and priced around the $3,500 mark, it's versatile and reliable.

This machine does need a constant connection to the internet to operate correctly. Despite that, it offers unmatched reliability and accuracy.

Small Business Winner: DXTECH-1309I

The DXTECH-1309I machine is a fantastic choice for small businesses. It's a small fiber laser cutting machine that is small enough to sit on most countertops while offering the ability to produce metal jewelry, metal accessories, ornaments, tools, and so on.

It can also handle flat cutting and engraving, drilling, and flying cutting. Due to it being a fiber machine, it's incredibly safe to use and offers protection for the user from laser radiation.

Finally, the machine has a welded cast iron bed with high stability and tensile strength, giving it a life of over 20 years with no deformities.

Best For Large-Scale Projects: DXTECH-1530F

The DXTECH-1530F machine is fantastic for large projects, not just because of its large size but because it has multiple laser powers to select from ranging from 500W-12000W. It's great for manufacturing electric cabinets, automobiles, elevators, aircraft, or even robots.

Because the user can customize the power, it can handle projects large or small and can even handle working with silicon steel, titanium alloy, or even carbon steel.

With over 100,000 hours of working life in the fiber module, it's able to be the perfect addition to any significant assembly line or large-scale production facility.

The only downside of this model is the cost: It can range between $48,000 and $52,000, but this is only a rough estimate of the actual cost of the unit. While it may not be the best option for home use, this machine is an excellent choice if you're looking for a machine that can do it all for a business.

Still, Lost?

Suppose you're still lost on the intricacies of laser cutting machines, no worries. We at Engineered Mechanical Systems can help with our newsletter. Sign up to learn everything about laser cutting, forming, inspection, and so much more. We've been providing diversified and quality fabrication and manufacturing services to a wide variety of customers since 1990, and we'd love to share that knowledge with you in our newsletter.

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