Glass Doctor

Mechanical Door Repairers install, service, or repair automatic door mechanisms and hydraulic doors. Includes garage door mechanics.

Heavy vehicle and mobile equipment service technicians inspect, maintain, and repair vehicles and machinery used in construction, farming, rail transportation, and other industries.

Heavy vehicle and mobile equipment service technicians typically do the following:

• Read and understand operating manuals, blueprints, and drawings
• Perform scheduled maintenance, such as cleaning and lubricating parts
• Diagnose and identify malfunctions, using computerized tools and equipment
• Inspect, repair, and replace defective or worn parts, such as bearings, pistons, and gears
• Overhaul and test major components, such as engines, hydraulics, and electrical systems
• Disassemble and reassemble heavy equipment and components
• Travel to worksites to repair large equipment, such as cranes

Heavy vehicles and mobile equipment are critical to many industrial activities, including construction and railroad transportation. Various types of equipment, such as farm machinery, cranes, and bulldozers, are used to move materials, till land, lift beams, and dig earth to pave the way for development and construction.

Heavy vehicle and mobile equipment service technicians repair and maintain engines, hydraulic systems, transmissions, and electrical systems of agricultural, industrial, construction, and rail equipment. They ensure the performance and safety of fuel lines, brakes, transmissions, and other systems.

With many types of equipment and mechanical and electrical systems, service technicians use diagnostic computers to identify problems and make adjustments or repairs. Although the use of computerized testing equipment, such as tachometers and dynamometers, is common, technicians also use many different power and machine tools, including pneumatic wrenches, lathes, and welding equipment.

Service technicians also use many different handtools, such as screwdrivers, pliers, and wrenches, to work on small parts and in hard-to-reach areas. They generally purchase these tools over the course of their careers, often investing thousands of dollars in their collections.

After locating malfunctions, service technicians repair, replace, and recalibrate components such as hydraulic pumps or spark plugs. This may involve disassembling and reassembling major equipment or making adjustments through an onboard computer program.

The following are types of heavy vehicle and mobile equipment service technicians:

Farm equipment mechanics service and repair farm equipment, such as tractors and harvesters. They also work on smaller consumer-grade lawn and garden tractors. Most mechanics work for dealer repair shops, where farmers increasingly send their equipment for maintenance.   

Mobile heavy equipment mechanics repair and maintain construction and surface mining equipment, such as bulldozers, cranes, graders, and excavators. Many work for equipment wholesale and distribution shops and large construction and mining companies. Those working for the federal government may work on tanks and other military equipment.

Rail car repairers specialize in servicing railroad locomotives, subway cars, and other rolling stock. They usually work for railroad, public and private transit companies, and rail car manufacturers.

For information about technicians and mechanics who work primarily on automobiles, see the profile on automotive service technicians and mechanics.

For information about technicians who work primarily on large trucks and buses, see the profile on diesel service technicians and mechanics.

For information about technicians and mechanics who primarily work on motorboats, motorcycles and small all-terrain vehicles, see the profile on small engine mechanics.

Glaziers install glass in windows, skylights, storefronts, and display cases to create distinctive designs or reduce the need for artificial lighting.

Glaziers typically do the following:

• Follow blueprints or specifications for size, color, type, and thickness of glass to be used
• Remove any old or broken glass before installing replacement glass
• Cut glass to the specified size and shape
• Make or install sashes or moldings for glass installation
• Fasten glass into sashes or frames with clips, moldings, or other types of fasteners
• Add weather seal or putty around pane edges to seal joints

Glass has many uses in modern life. For example, insulated and specially treated glass keeps in warm or cool air and controls sound and condensation. Tempered and laminated glass makes doors and windows more secure. The creative use of large windows, glass doors, skylights, and sunroom additions makes buildings bright, airy, and inviting. Glaziers specialize in installing these different glass products.

In homes, glaziers install or replace windows, mirrors, shower doors, and bathtub enclosures. They fit glass for tabletops and display cases. On commercial interior projects, glaziers install items such as heavy, often etched, decorative room dividers or security windows. Glazing projects also may involve replacing storefront windows for supermarkets, auto dealerships, banks, and so on.

Workers who replace and repair glass in motor vehicles are not covered in this profile. For more information, see the profile on automotive body and glass repairers.  

For most large scale construction jobs, glass is precut and mounted into frames at a factory or a contractor's shop. The finished glass arrives at the jobsite ready for glaziers to position and secure into place. Using cranes or hoists with suction cups, workers lift large, heavy pieces of glass for installation. In cases where the glass is not secure inside the frame, glaziers may attach steel and aluminum sashes or frames to the building, and then secure the glass with clips, moldings, or other types of fasteners. 

A few glaziers work with plastics, granite, marble, and other materials used as glass substitutes.  Some work with films or laminates that improve the durability or safety of the glass.

Woodworkers build a variety of products, such as cabinets and furniture, using wood.

Woodworkers typically do the following:

• Read detailed schematics and blueprints
• Prepare and set up equipment
• Lift wood pieces onto machines, either by hand or with hoists
• Operate wood-making and cutting machines
• Listen for unusual sounds or detect excessive vibration
• Ensure that products meet specifications, making adjustments as necessary
• Use hand tools to trim pieces or assemble products
• Remove and replace dull saw blades

Despite the abundance of plastics, metals, and other materials, wood products continue to be an important part of our daily lives. Woodworkers make wood products, using lumber and synthetic wood materials. Many of these products are mass produced, including most furniture, kitchen cabinets, and musical instruments. Other products are custom made with specialized tools in small shops.

Although the term “woodworker” may evoke the image of a craftsman who builds ornate furniture using hand tools, the modern woodworking trade is highly technical and relies on advanced equipment and highly skilled operators. Workers use automated machinery, such as computerized numerical control (CNC) machines, to do much of the work.

Even specialized artisans generally use a variety of power tools in their work. Much of the work is done in a high-production assembly line facility, but there is also some work that is customized and does not lend itself to being made in an assembly line. Woodworkers are employed in every part of the secondary wood products industry, from sawmill to finished product, and their activities vary.

Woodworkers set up, operate, and tend all types of woodworking machines, such as drill presses, lathes, shapers, routers, sanders, planers, and wood-nailing machines. Operators set up the equipment, cut and shape wooden parts, and verify dimensions, using a template, caliper, and rule. After wood parts are made, woodworkers add fasteners and adhesives and connect the pieces to form a complete unit. They then sand, stain, and, if necessary, coat the wood product with a sealer, such as a lacquer or varnish.

Many of these tasks are handled by different workers with specialized training.

The following are types of woodworkers:

Cabinetmakers and bench carpenters cut, shape, assemble, and make parts for wood products. They often design and create sets of cabinets that are customized for particular spaces. In some cases, their duties begin with designing a set of cabinets to specifications and end with installing them.

Furniture finishers shape, finish, and refinish damaged and worn furniture. They often work with antiques and must judge how to best preserve and repair them. They also do the staining and sealing at the end of the process of making wooden products.

Wood sawing machine setters, operators, and tenders specialize in operating specific pieces of woodworking machinery. They often operate computerized numerical control (CNC) machines.

Woodworking machine setters, operators, and tenders, except sawing, operate woodworking machines, such as drill presses, lathes, routers, sanders, and planers.

Automotive service technicians and mechanics, often called service technicians or service techs, inspect, maintain, and repair cars and light trucks.  

Automotive service technicians and mechanics typically do the following:

• Test parts and systems to ensure that they are working properly
• Identify mechanical problems, often by using computerized diagnostic equipment
• Follow checklists to ensure that all critical parts are examined
• Test and lubricate the vehicle's engine and other major components
• Perform basic care and maintenance, including oil changes, tuneups, and tire rotations
• Repair or replace worn parts, such as brake pads and wheel bearings
• Disassemble and reassemble parts
• Use testing equipment to ensure that repairs and maintenance are effective
• Explain to clients their automotive problems and the repairs done on their vehicles

Service technicians work on traditional mechanical components, such as engines, transmissions, belts, and hoses. However, they must also be familiar with a growing number of electronic systems. Braking, transmission, and steering systems, for example, are controlled primarily by computers and electronic components.

Other integrated electronic systems, such as accident-avoidance sensors, are becoming common as well. In addition, a growing number of technicians are required to work on vehicles that run on alternative fuels, such as ethanol and electricity.

Service technicians use many different tools, including computerized diagnostic tools and power tools such as pneumatic wrenches, lathes, welding torches, and jacks and hoists. These tools usually are owned by their employers.

Service technicians also use many common handtools, such as pliers, wrenches, and screwdrivers, which generally are their own. In fact, experienced workers often have thousands of dollars invested in their personal tool collection.

Service technicians sometimes specialize in a particular type of repair that may be subject to specific regulations or procedures. For instance, those focused on air-conditioning system repairs must follow federal and state regulations governing the handling, recycling, and disposal of refrigerants.

In some shops, technicians may specialize. The following are types of service technicians:

Automotive air-conditioning repairers install and repair air conditioners and service parts, such as compressors, condensers, and controls. They are trained in government regulations related to their work.

Brake repairers adjust brakes, replace brake linings and pads, and make other repairs on brake systems. Some technicians specialize in both brake and front-end work. 

Front-end mechanics align and balance wheels and repair steering mechanisms and suspension systems. They frequently use special alignment equipment and wheel-balancing machines.

Transmission technicians and rebuilders work on gear trains, couplings, hydraulic pumps, and other parts of transmissions. Extensive knowledge of computer controls, the ability to diagnose electrical and hydraulic problems, and other specialized skills are needed to work on these complex components.

Tune-up technicians adjust ignition timing and valves and adjust or replace spark plugs and other parts to ensure efficient engine performance. They often use electronic testing equipment to isolate and adjust malfunctions in fuel, ignition, and emissions control systems.

For information about technicians who work on large trucks and buses, see the profile on diesel service technicians and mechanics.

For information about technicians who work on farm equipment, construction vehicles, and rail cars, see the profile on heavy vehicle and mobile equipment service technicians.

For information about technicians who repair and service motorcycles, motorboats, and small all-terrain vehicles, see the profile on small engine mechanics.