Toolbox Topic: Nail Gun Safety
The importance of nail gun safety should become fairly apparent in a few minutes when we discuss the mind-boggling number of injuries every year due to nail gun incidents! In this episode, we will discuss the dangers you may face when operating a nail gun and the precautions you should take to stay safe.
Definitions
According to Wikipedia, a nail gun, or nailer, is a form of hammer used to drive nails into wood or other materials.
There are several different types of nail guns.
There are (pneumatic) nail guns that are driven by compressed air.
Electromagnetic nail guns are battery-powered and drive the nail by creating an electromagnetic field around a coil (which acts as a piston), forcing the nail out of the chamber.
Fuel-powered nail guns use highly flammable gases such as butane or propane. A tiny amount of gas is released, and an electric charge (produced by a battery) ignites the gas that explodes, which drives the piston to force the nail out.
There are also powder-actuated nail guns used to join materials such as steel and concrete. These nail guns work very much like a firearm. A small explosive cartridge is triggered when the firing pin strikes the primer. The primer ignites the powder, causing it to burn rapidly. This rapid burn builds pressure within the cartridge, which creates an exploding force on the head of the fastener, rapidly driving the fastener out of the muzzle.
History
The “Spruce Goose” and the Pneumatic Nail Gun
The year was 1942, and the U.S. War Department needed to transport large payloads of personnel and supplies to Britain. Howard Hughes, founder of the Hughes Aircraft Company, would attempt to build an aircraft for that purpose. It would be the largest aircraft ever built. He signed a contract with the U.S. Government, and development began later that year. Due to restrictions imposed during WW2 on steel, Hughes would build his aircraft, the H-4 (which he called The Hercules), out of wood. It was constructed mainly of birch and some spruce wood which is how its critics came up with the nickname “The Spruce Goose.” Howard, however, was not amused. The massive wooden aircraft would have a wingspan longer than a football field, was powered by eight giant propeller engines, and would carry 150,000 pounds (68,000 kg), 750 fully equipped troops, or two 30-ton M4 Sherman Tanks.
Construction would require bonding layers of wood together using three different types of epoxy glues. The big problem was that it needed to be held together until the glue had cured. Using nails could do the job, but considering the sheer size of the plane, it would take an awful lot of them. In 1944 necessity would again be the mother of invention. Morris Pynoos, a civil engineer, would solve this problem and help Hughes build his massive plane. He would invent the first pneumatic nail gun. Ultimately, the nail gun was vital as the project would require some 8000 nails to hold the wood layers together. Later, they would have to be removed using specially designed nail pullers.
The development of the H-4 took so long that the war ended before its completion in 1946. Critics claimed that it would never fly. Some detractors in congress even accused Hughes of being a war profiteer and demanded that he prove the plane was airworthy. So, in November of 1947, Hughes took The Hercules out for a flight test. Getting the behemoth out to long beach caused quite a stir. Crowds gathered, and members of the media came to see if Howard Hughes’s giant five-story plane could actually fly! The aircraft taxied on the water, and with some shock and awe, Hughes flew the airplane 70 feet above the water and over a mile before landing.
Although the maiden flight was successful, the Hercules never went into production. The cost of developing the plane reached $23 million, which would have been $213 million in 2020 dollars. Today, the H-4 is housed by the Evergreen Aviation Museum in McMinnville, Oregon.
Following Morris Pynoos’s nail gun, the first pneumatic nail guns would come to market in the 1950s. With time came efficiency, and using these nail guns, operators could fire one nail per second, with a capacity of 400-600 nails. Today nail guns can fire up to 10 nails per second!
Statistics
Nail guns are responsible for an estimated 37,000 emergency room visits every year – 68% of these are workplace injuries, and the other 32% involve consumers.
How likely are nail gun injuries? A study of apprentice carpenters found that:
• 2 out of 5 were injured using a nail gun during their four years of training.
• 1 out of 5 was injured twice.
• 1 out of 10 was injured three or more times.
More than half of nail gun injuries are to the hand and fingers. One-quarter of these hand injuries involve tendons, joints, nerves, and bones. After hands, the next most often injured body parts are the leg, knee, thigh, foot, and toes. Serious nail gun injuries to the spinal cord, head, neck, eye, internal organs, and bones can result in paralysis, blindness, brain damage, bone fractures, and even death.
Safety Tips
Safety Tip#1 Know the Seven Major Risk Factors that Can Lead to Injury
- Unintended nail discharge from double fire
- Unintentional nail discharge from hitting the safety contact with the trigger squeezed
- Nail penetration through the workpiece
- Nail ricochet after striking a hard surface or metal feature
- Missing the intended workpiece
- Awkward position nailing
- Bypassing safety mechanisms.
Tip#2 Understand How Triggers Differ
All nail guns rely on two basic controls: a finger trigger and a contact safety tip located on the nose. Trigger mechanisms can vary based on:
- the order in which the controls are activated, and
- whether the trigger can be held in the squeezed position to discharge multiple nails OR if it must be released and then squeezed again to fire each nail. Combining these variations gives four kinds of triggers. Some nail guns have a selective trigger switch, allowing the user to choose among two or more trigger systems.
The point here is to know the type of trigger your nail gun has and act accordingly.
Tip#3 Do’s
Do:
- Have operation manuals available.
- Understand and follow the manufacturers’ labels and instructions.
- Inspect tools and check power sources before operating. Take defective nail guns out of service immediately.
- Check lumber surfaces for knots, nails, straps, hangers, or anything that could cause recoil or ricochet.
- Keep hands at least 12 inches away from the nailing point. Consider using clamps to brace materials instead of using your hands.
- Always fire nail guns away from you and your co-workers.
- Recognize that working in awkward positions creates certain dangers and provide extra time and precautions.
- When toe-nailing, use a nail gun with teeth on the safety contact to bite into the workpiece to keep the gun from slipping.
- Recognize the dangers when working at height and provide extra time and precautions:
- Consider using scaffolds instead of ladders.
- Use full sequential trigger nail guns to prevent injuries that could occur from bumping a leg while climbing a ladder.
- Position ladders, so you don’t have to reach too far. Your belt buckle should stay between the side rails. Always maintain three points of contact.
Tip#4 Don’ts
Don’t:
- Ever bypass or disable nail gun safety features.
- Lower the nail gun from above or drag the tool by the hose. If the nail-gun hose gets caught on something, don’t pull on the hose. Go and find out what is causing the problem and release the hose.
- Use the nail gun with the non-dominant hand.
Tip#5 PPE
PPE is the last line of defense! Always don the following PPE before using a nail gun:
- Safety shoes/steel-toed boots or metatarsal boots for the most protection
- Hard hats
- High Impact eye protection – safety glasses or goggles marked ANSI Z87.1
- Hearing protection – either earplugs or earmuffs
Sources
https://www.cdc.gov/niosh/newsroom/feature/nailgunsafety/default.html
https://www.osha.gov/sites/default/files/publications/NailgunFinal_508_02_optimized.pdf https://www.history.com/this-day-in-history/spruce-goose-flies https://www.youtube.com/watch?v=U_5ioLKGj24&ab_channel=Wallybois https://www.jlconline.com/tools/fastening-tools/a-brief-history-of-portable-nail-guns_o https://www.youtube.com/watch?v=-zZnPOFqL4E&ab_channel=HandToolRescue https://www.constructionjunkie.com/blog/2017/7/6/video-watching-an-early-1900s-antique-nail-gun-be-restored-is-so-satisfying
https://en.wikipedia.org/wiki/Hughes_H-4_Hercules
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