6.3 Home Shop VS Fabrication Shop
David Ridge
Some people are interested in welding as a career. Others simply want to do it for themselves as a hobby or maybe a side business. The path you choose in welding will largely determine the kinds of tools and equipment you encounter and the size of shops you work in. There will be differences in what equipment may be found in a home shop or garage versus an industrial fabrication shop, as well as their capabilities. A few factors contribute to those differences, and we’ll review them here.
Power Supply
Power supply constitutes a major difference between a home shop and a fabrication shop. Most residential service drops (electrical line connected to a utility pole) do not exceed 200 amps, split between all circuits connected to it. The available voltage will be 110V/120V and 220V/240V, and the number of circuits may be limited. In contrast, a decent-size fabrication shop can have a service drop of several thousand amps, with dozens of circuits and voltages up to 480V. Additionally, many circuits in large shops are wired for three-phase power, which is a three-wave version of alternating current required for some machinery such as large electric motors. These high-powered electrical circuits require large circuit breakers, such as up to 50 amps.
This difference in available power influences the size and number of machines and equipment a shop has. It is important to match the lineup of welders and other tools with the power supply. For instance, it wouldn’t make sense to buy a welder that required more power than was available at the shop.
Application
It is fairly common sense that the smaller a shop, the more limited it is in its work capacity simply due to space. Shop space is not only important for the room that is necessary to work on projects, but also for how much equipment can reasonably fit in the shop. Large fabrication shops specialize their workspace for the size and type of material they handle and the products they put out, streamlining to increase production. This is not to say that home shops or small shops can’t do lots of work, but that they must be somewhat selective in the types of things they work on. This means many home shops and other small fabrication outfits produce quality products, but usually in less quantity and size.
Another factor determining a shop’s workload limit and type of work is the number of persons working at one time. For a home shop where the welder is simply working as a hobby, this isn’t a big issue. But a small business run from a garage or small workshop can be limited in how many people they can bring in to work. This greatly affects the business’ time and capabilities, specifically the number of hours that can be put towards finishing a product. AAs an example, one person working a standard 40-hour week will only ever put in 40 hours of work per week. If a job is estimated to take 120 hours, it would take that person three weeks to finish it. Simply adding a second person brings the working hours to 80 per week, cutting the production time in half as far as delivering the product. This is not a perfect example, but it gives you a picture of this concept: Shops that have more workers can complete tasks faster. Additionally, it is easier to work on large weldments in a team of two or three people. However ,it is worth repeating the point that a limited number of workers does not necessarily mean lower quality of the work.
One outlier in the field of small welding operations is mobile welders, who travel around with all their equipment. Sometimes they are part of a larger organization, but often they are an individual welder in business for themselves. Mobile welding businesses are purposefully small because everything the welder needs has to fit, usually, on a single truck. Mobile welders are skilled professionals who know how to get by with the minimum amount of tools and equipment, and the value of these small operations is in their necessity. These welders service customers who have a broken piece of equipment that needs to be repaired immediately or need something built in an area where no welding shops exist or are willing to do the work. Therefore, these customers are usually willing to pay handsomely for the work to be done.
Material Handling
One aspect of welding and fabrication that often gets overlooked until it is too late is material handling. This isn’t too much of a problem for the hobbyist in their own garage, as the projects they work on will likely be small. But as a shop starts to take on larger projects, material handling can become a limiting factor.
Metals are fairly heavy, and particularly steel, with a weight of 0.283 lbs per cubic inch (7.85 grams per cubic centimeter). To put this in perspective, a one inch (2.5 cm) square bar of steel one foot (30.5 cm) long weighs just under 3.5 lbs (1.56 kg). One cubic foot of steel weighs 489 lbs (221.81 kg). Weight is not the only issue either. Space can be a challenge as well, as many steel bars, angles, channels, tubes, and pipes often come in standard lengths of 20 feet (6.1 m). Plate and sheet steel often come four feet (1.2 m) wide and anywhere from 4–20 (1.2 m to 6.1 m) long.
This is to say that, at a certain point, it is not possible to move materials yourself and material handling equipment and machinery need to be considered. Things like forklifts, hoists, and cranes are common in large shops, but a garage shop might find the expense and space requirements of these tools to be out of their reach. While there are small hoists and hand-powered fork trucks , they may not be sufficient to handle large materials if the need arises.
All material handling tools have weight limits that must be considered before moving any object. And understanding the material handling needs of any project and whether your shop can accommodate it is an important step to take before beginning the work.
Shop Safety
As with everything in the welding and fabrication industry, safety when considering tools, equipment, and the welding shop is important. Remember that working safely is always your responsibility. No amount of rules, regulations, or precautions is a substitute for common sense and being aware of your environment. Building a good safety mindset should be just as much a part of learning to weld as the welding skills themselves.
Tool safety is such a broad category that it would be difficult to list every possible hazard. However, keep the following things in mind when working with the tools covered in this chapter.
It is important to maintain any tool in good working order. If a tool or an accessory of a tool becomes damaged, it is better to take it out of service until it can be repaired or replaced.
Many hand tools can get burs or sharp edges as they are used. Wear gloves as often as possible and make sure such burs and sharp edges are filed or sanded off as they appear.
Almost all power tools and shop equipment have guards or other safety features. Never use a tool or piece of equipment without the safety features in place.
Many power tools, such as grinders and drills, have trigger locks that allow the tool to keep working without the operator needing to constantly hold the power switch on. Make sure the trigger lock is off before plugging in a tool, or else it could start up unexpectedly while being held in a hazardous manner.
Never set a power tool down or leave a piece of equipment until it has completely stopped or shut down.
All power tools and pieces of shop equipment have moving parts. While keeping any part of your body or clothing from touching these moving parts is important, it is especially important with rotating parts, such as a spindle or wheel, since they have a tendency to grab clothes and pull you in.
Keep your body parts and clothing away from power tools and equipment with clamping or shearing functions, as these will crush or cut off whatever is put in them. Don’t allow any body parts to get in between these tools and the material they are clamping or shearing, as this can result in body parts being pinched and crushed.
Follow all electrical safety guidelines for working with power tools and equipment. Keep an eye out for damaged power cords and other electrical components and take any compromised equipment out of service. Be sure a machine’s power switch is off before plugging it in or unplugging it. If a high-voltage cable is damaged, turn off the breaker before handling it or unplugging it.
Take cautions when involved with material handling. Be aware of other workers moving material around you, and always alert others to your presence if you are the one moving material. Never try to lift a heavy object by yourself. If the material is too heavy to lift safely by hand, always use an appropriate machine or device. Stay out of the path of hoists, cranes, or forklifts and never put yourself or any part of your body under the material or in any pinch points between the material being moved and stationary objects. When lifting material with a crane or hoist, stay to the side of it and always keep one hand or a rope (called a tagline) on it to keep it from swinging. No matter how you are moving material, be careful not to hit any shop equipment or other objects in your path. If a piece of material falls and lands on a power cable or air line, be cautious, as severed power cables and air lines should be shut off at the source before being handled.
Compressed air in a shop can be more dangerous than most people realize and requires special precautions. Wear eye protection while usingequipment that eject air from a vent somewhere on the tool, which can kick up debris from grinding, sanding, or cutting. Compressed air can also contain moisture from the compression process. This moisture can travel through the pneumatic hoses that attach to air tools and can be blasted into electrical equipment. This is especially dangerous with plasma-cutting tools. Attach a moisture filter to the air compressor to prevent this hazard.
If an air hose is severed, it can whip around wildly if there is enough air pressure. Do not try to grab a flailing air line, as you could be struck and injured in the process. Instead, shut off the air at the compressor or manifold before picking up the hose.
Compressed air alone can be dangerous. Be very careful with air nozzles that are commonly used to blow dust and debris off parts and never put an air nozzle directly against your skin: the air can be at such a high pressure that it can penetrate your skin. This may cause an air bubble, called an embolism, to enter your bloodstream, which can work its way to your heart and cause death.
Finally, never substitute compressed oxygen for compressed air. Oxygen is one of the three elements on the fire triangle. While not a flammable gas in and of itself, it makes everything it touches flammable. If you were to use oxygen to blow debris off a part or your clothes, or somehow attach an oxygen line to a pneumatic tool, you would have just saturated everything in the area with oxygen. Then all it would take is for a small spark to ignite the oxygen-rich environment.
Working in a fabrication shop of any kind means working in a hazardous environment. However, these hazards are overcome by safe work practices. Hundreds of thousands of people in America and around the world work safely and effectively in these environments every day. They succeed by paying attention and working in a common sense manner. With training and practice, you will also.