toxicz28
07-09-2005, 11:55 AM
To All;
Matt asked me to write a post here about welding safety. Since our hobby will involve metal fabricating (welding,cutting, grinding, and brazing) sooner or later, I was more than happy to oblige.
What I am going to post is a combination of my personal experiences, research, what I have learned, and most importantly NOT learned in trade schools and classes throughout the years. I will cover SAFETY issues only. Of course, if anyone has anything to add to this, please, feel free to do so! I also attached some pictures of welding shields, and respirators at the end.
First, I'd like to tell you a little bit about myself. My name is Rob and I'm 32 years old. Above all, I am a car nut! Since I have to be a (semi) responsible adult and keep my kids fed and the lights on, I get money by being a structural Ironworker and a certified weldor. I have been doing this for the better part of 15 years. My father is also a structural Ironworker, and was once a certified weldor also. I was 4 the first time I was in a fab shop, 10 the first time I picked up a cutting torch and a welding lead, 16 for my first "formal" welding class, 18 when I worked in a nuclear power plant the first time (20' beneath the reactor), and 23 when I took and passed both the New York City (destructive bend test) and New York state (non-destructive x-ray test) welding tests.
I'll stop boring you with details about my life now, and start boring you with safety!
The first thing you should know about, and probably the most important is the:
Material Safety Data Sheet or MSDS: According to OSHA, ALL materials and chemicals that can be found in the workplace are required to have an MSDS. This includes welding wire, tungstens,and argon,( I've even seen one for distilled water) OSHA also mandates that the employer keep copies of them on file for an employee (you) to review at their request without fear of reprisal. My suggestion, the next time you run to Lowe's to pick up a 2lb. spool of wire, READ that piece of paper that's folded up and taped to the back. Don't just throw it away. You can also find them here for free http://www.wmsds.com. Their selection is limited, they just have them for electrodes and filler metal.
Fire Extinguishers: Aside from a welding machine, the MOST important piece of equipment in a welding shop! These should be kept close to the area where the welding is being done. Depending on the process, you are dealing with a flame or an electric arc, and definitely molten metal. Also, if there is grinding going on, there are sparks involved. Any one of these things can start a fire! I've set myself on fire several times while welding. (sorry Matt, no one was around to appreciate it)
Protective Clothing: Natural materials like leather and cotton (yes I know cotton burns, but it doesn't melt like the synthetics do. and melting clothes is a whole lot worse than burning clothes) Jeans, long sleeve shirts, boots (leather, over the ankle, laced up with pant leg over them. When you drop a hot spark down your boot, you can't get it off fast enough. Trust me, I know) welding caps, jackets, and if need be, chaps. Also a good pair of leather gloves!( Mechanix gloves are synthetic. They melt!) Make sure you pick the right gloves for the job too. You don't want to try to tig weld with heavy arc welding gloves on, just like you don't want to try to arc weld with light tig gloves on.
Welding Shields: (The topic that started it all!) They range in price from $15-30 for you basic fixed lens child, up to $1000+ (yes that is one thousand) for an adjustable auto darkening with peripheral view and PAPR (I'll get into that soon enough) and with shades ranging from #5 up to #14. I do recommend the auto darkening shields (I have 2 of them. A Jackson that is nice and sturdy but a pain to adjust that I use at work, and a Miller that is a breeze to adjust, but the shield part feels a little flimsy for my tastes, that I use at home.) There are even full-face respirators with clip on welding Shields. They are bulky,hot, and heavy, but they provide a tremendous amount of protection. If you decide to invest in an auto-dark shield, make sure it is easily adjustable! And, when you first start out with it, set it at its darkest setting, and then work your way down until you can SAFELY see the weld area.
Other Eye Protection: Oxy/Acetylene cutting, welding and brazing, as well as grinding and cutting with a cut-off wheel(wizzer) does require eye protection, but not necessarily a welding shield. For torch work, a #5 shaded glass is recommended. They can be glasses, goggles, or even used in a welding shield. Cutting and grinding is a little different, because of the amount of sparks created. A clear face shield is suggested when doing this. Some employers now require it. I use an old 4"x5" fixed shield with only clear glass in it.
Ear/ Hearing Protection: It gets really loud when you're grinding or cutting with a wheel for a while. To keep from getting that ringing, soft foam earplugs work fine. Also, stray sparks and weld spatter CAN bounce into your ear canal. Trust me, it is really painful!! Foam earplugs will stop this from happening.
Respiratory Protection: OSHA assigns a PEL (Permissable Exposure Limit) to all known chemicals that could become a dust, fume, or vapor (dust and fumes are solids, vapors are liquids). These values are assigned for unprotected breathing, and are usually a weight per cubic meter of air (mg/m3). There are many types of respirators on the market that provide different levels of protection. There are also many different types of filters, each type protects you from a different type of nuisance.
Half face respirators- exactly as stated. Covers half of your face, offers no vision protection. Respiratory protection at the rate of 10x the PEL.
Full face respirators- Respirator covers the entire face offering eye protection. Respiratory protection at a rate of 100x the PEL.
PAPR (Powered Air Purifying Respirator)- Consists of a battery pack that straps to your waist that powers a fan that filters, then pumps the air to you. Makes it a little easier to breathe. DO NOT CONFUSE PAPR WITH FORCED AIR!!! THAT MISTAKE CAN KILL YOU!!!
Forced air respirator- Available in both half and full faced models. Consists of a remote compressor with filters and a hose that pumps the air to the facepiece. Two things to remember: 1. All equipment must be suitable for breathing air! 2. The air is only as good as the air where the compressor is set up.(don't set it up in your garage and think it will be ok to spray urethane paint in there!)
SCBA (Self Contained Breathing Apparatus)- Similar to SCUBA,however it is not rated for underwater use( SCOTT packs for the fire fighters). It consists of an air tank strapped to your back connected, by a hose, to the facepiece (almost always full face). Perfect for low oxygen, toxic, or IDLH (Immediately Dangerous to Life or Health) environments Obviously, the increase to the PEL is infinite. The only limiting factor is the amount of air in the tank.
Lead: Used as a body filler in quarter panel and A-pillar seams. In it's solid state, there is no danger. When melted (to remove it) it releases some fumes. However, when it is welded on (lead leaches into steel, so it is NEVER really gone), it is vaporized and a very high concentration of fumes are released. Respiratory protection is HIGHLY recommended. MAGENTA filters are used for lead protection!!
Compressed Gas Cylinders: If you MIG/TIG weld, or use an OXY/Acetylene torch set up, you will be using compressed gas cylinders.
Acetylene tanks: store Acetylene at 220 psi. It is flammable, but it is not explosive like propane is. As a safety, to prevent extreme pressure buildup in the event of a fire, Acetylene tanks have lead plugs on the bottom that will melt, leaking out the Acetylene.
High Pressure Tanks( Oxygen, Argon, CO2, etc.): These store gasses at a very high rate of pressure(2000-2200 psi when full). There is no safety measure like an Acetylene tank, so if exposed to fire, the tank could rupture and explode! Also, the valve of the tank is only brass, and therefore fragile. That is why these tanks have a steel cap to protect the valve in transport. Full, these tanks could take off like a rocket if the valve breaks off(2200 psi squeezing through a 1/4" hole)! My high school welding teacher said that he witnessed an O2 tank go through the hull of a ship!
Gasses
Argon- Used primarily as a shielding gas for MIG and TIG welding, either pure(mig welding aluminum) or mixed with other gasses such as CO2 (mig mild steel) and helium and CO2 (mig stainless steel). Also used to purge gas tanks for welded repairs (DO NOT TRY THIS AT HOME!!!) and to back gas stainless pipe or tube for mig and tig welding. Argon, being heavier than air, will collect in low, unventilated areas and displace all breathable air. From an argon msds:
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SECTION VI - HEALTH HAZARD DATA
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THRESHOLD LIMIT VALUE: ARGON IS AN ASPHYXIANT AND HAS NO THRESHOLD LIMIT VALUE.
EFFECTS OF OVER EXPOSURE: ARGON MAY INDUCE SUFFOCATION BY DILUTING THE CONCENTRATION OF OXYGEN IN AIR TO LEVELS LOWER THAN IS NECESSARY TO SUPPORT LIFE. EXPOSURE TO OXYGEN DEFICIENT ATMOSPHERES MAY PRODUCE DIZZINESS, NAUSEA, LOSS OF CONSCIOUSNESS, VOMITING AND DEATH. IMPAIRED MUSCULAR COORDINATION. DIMINISHED MENTAL ALERTNESS.
EMERGENCY AND FIRST AID PROCEDURES: REMOVE VICTIM TO AREA OF NORMAL OXYGEN CONTENT. SELF-CONTAINED BREATHING APPARATUS MAY BE REQUIRED TO PREVENT ASPHYXIATION. ASSISTED RESPIRATION AND SUPPLEMENTAL OXYGEN SHOULD BE GIVEN
IF THE VICTIM IS NOT BREATHING.
Helium- Used to fill ballons, make your voice funny, and mixed with argon and co2 for welding purposes. From the helium msds:
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SECTION VI - HEALTH HAZARD DATA
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THRESHOLD LIMIT VALUE: SIMPLE ASPHYXIANT
EFFECTS OF OVER EXPOSURE: ASPHYXIANT. SYMPTOMS OF FATIGUE, SLEEPINESS, LOSS OF COORDINATION, CONFUSION AND COLLAPSE MAY OCCUR. LIQUID CONTACT CAN CAUSE FREEZE BURNS.
EMERGENCY AND FIRST AID PROCEDURES: REMOVE VICTIM TO FRESH AIR. RESTORE AND/OR SUPPORT BREATHING AS NECESSARY. ADMINISTER OXYGEN IF AVAILABLE.
Oxygen- An oxidizer, used with acetylene for cutting and welding. Note: The air we breathe is roughly 20% oxygen. The range of oxygen that we need to survive is 17% up to 24%. Yes, too much can harm you just as much as too little. Also, pure oxygen should not be mixed with certain materials, such as oil or grease. the result could be explosive!
SECTION V - REACTIVITY DATA
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STABILITY: STABLE
INCOMPATIBILITY (MATERIALS TO AVOID): REACTS WITH EXPLOSIVELY WITH PHOSPHINE, HYDRAZINE, ETHERS, ALCOHOLS, HYDROGEN SULFIDE, HYDROCARBON, ETC.
HAZARDOUS DECOMPOSITION PRODUCTS: N/A
HAZARDOUS POLYMERIZATION: WILL NOT OCCUR.
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SECTION VI - HEALTH HAZARD DATA
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THRESHOLD LIMIT VALUE: N/A
EFFECTS OF OVER EXPOSURE: EXTENDED EXPOSURES TO O2 AT HIGHER PRESSURES MAY BE HAZARDOUS. A VARIETY OF CENTRAL NERVOUS SYSTEM EFFECTS MAY RESULT FROM BREATHING O2 GREATER THAN 2 ATM., SUCH AS DIZZINESS, IMPAIRED COORDINATION, VISUAL AND HEARING DISTURBANCES AND SEIZURES.
EMERGENCY AND FIRST AID PROCEDURES: REMOVE TO FRESH AIR.
Acetylene(dissolved)- Used at low pressures (less than 15psi) to cut, weld and braze.
From the msds:
Potential Health Effects
Inhalation : May cause anesthetic effects. In high concentrations may cause asphyxiation.
Symptoms may include loss of mobility/consciousness.Victim may not be aware of asphyxiation. Asphyxiation may bring about unconsciousness without warning and so rapidly that victim may be unable to protect themselves.
Filler metals, Fluxes, And Tungsten
This is where the really nasty stuff is! I'll break it down to the 3 most common metals that would be welded or brazed on a car, and then the fluxes as a general, and tungsten.
Note: When you see CHROMIUM listed, it can contain CHROMIUM VI. This is carcinogenic! If your wives/ girlfriends "made" you watch "Erin Brockovich", this is the same stuff!!!
Mild Steel: The most common metal on a car. Typical ER70S2 (MIG/TIG wire) wire itself contains any and all of :Aluminum, Carbon, Chromium, Copper, Iron, Manganese, Molybdenum, Nickel, Silicon, Titanium, Vanadium, Zirconium
Stainless Steel: Found in more exhaust systems these days. ER 3xx (308-347)series wire contains any and all of the following:IRON, MANGANESE, NICKEL, CHROMIUM, SILICON, MOLYBDENUM
Aluminum: Found in A/C systems and on more and more radiators contains any and all of the following: Aluminum, Magnesium, and Silicon
Brazing(low fuming bare and flux coated): Brass/Bronze rods used to join sheet metal with an oxy/Acetylene torch. Contains: Copper, Zinc, Tin, Manganese, Iron, Silicon
The flux coating contains any and all of the following: Boric Acid, Methacrylate/Aliphatic & Naphthenic Hydrocarbon Compound, Borax Glass
Flux covered SMAW (shielded metal arc welding) electrodes:
Mild Steel(7018, 6010, 9018,etc.,etc.) Contain any and all of the following: IRON, MANGANESE, ALUMINUM OXIDE, CALCIUM CARBONATE, CELLULOSE, MICA, SILICA, SILICON, TITANIUM DIOXIDE, FLUORSPAR, CHROMIUM, NICKEL, MOLYBDENUM, MAGNESIUM CARBONATE, SILICATE BINDERS
Stainless Steel and Cast Iron (E308L-16, E309L-16, E316L-16,etc.) Contain any and all of the following: IRON, CHROMIUM, NICKEL, CALCIUM CARBONATE, FLUORSPAR, MANGANESE, SILICA, TITANIUM DIOXIDE, SILICON, ALUMINUM OXIDE, MOLYBDENUM, COPPER, COLUMBIUM, TUNGSTEN, SILICATE BINDERS, ZIRCONIUM, MICA, STRONTIUM CARBONATE,ALUMINUM, MAGNESIUM, ANTIMONY TRIOXIDE, BARIUM CARBONATE
Aluminum (E4043) Contains all of the following: Aluminum, Silicon, Aluminum Fluoride, Lithium Flouoride, Magnesium Fluoride, Potassium Chloride, Potassium Fluoride, Sodium Chloride
Tungsten: Aside from tungtsen, it could contain thoria (2% thoriated), or Lanthana (1.5% Lanthanated)
Lead: Used as a filler from the 1920's up to the early 1970's. Usually a 70/30 mix (70%lead 30% tin)
Hazards
Aside from the standard "electric shock can kill" warning. There is the standard warnig that is on most products these days "WARNING: This product, when used for welding or cutting, produces fumes or gases which contain chemicals known to the state of California to cause birth defects (or other reproductive harm), and in some cases, cancer. (California Health and Safety Code 25249.5 et seq.)"
Also:
Radiation burns- Electric arc welding, whether it be arc, mig, or tig, producesan intense ammount of ultraviolet radiation and that causes burns on both the skin, and the eyes. On the skin, the symptoms of radiation burn is identical to that of a sunburn. On the eyes, somtimes called "welding flash" or "arc eye", the only way I can describe it is like someone threw sand in my eyes. Yes, I've been flashed before. The first time, the weldor was 50 feet away from me, and I didn't realize it untill about 10 hours later. What it is, is a third degree burn, or sunburn, on your corneas. You don't even know it's there. It does blister, and the blisters pop because of eye movements and blinking. IT HURTS!!!
Burns: You are dealing with fire, electric arcs, and molten metal. Even if you are wearing the right clothing, you could still get burned.
Other effects( by filler metal)
Aluminum
Short-term (acute) overexposure to welding fumes may result in discomfort such as metal fume fever, dizziness, nausea, or dryness or irritation of nose, throat, or eyes. May aggravate pre-existing respiratory problems (e.g. asthma, emphysema).
Long-term (chronic) overexposure to welding fumes may affect pulmonary function. Bronchitis and some lung fibrosis have been reported.
WARNING: This product contains or produces a chemical known to the State of California to cause cancer and birth defects (or other reproductive harm). (California Health & Safety Code Section 25249.5 et seq.)
Arc Rays can injure eyes and burn skin. Skin cancer has been reported.
Electric Shock can kill. If welding must be performed in damp locations or with wet clothing, on metal structures or when in cramped positions such as sitting, kneeling or lying, or if there is a high risk of unavoidable or accidental contact with workpiece, use the following equipment: Semiautomatic DC
Welder, DC Manual (Stick) Welder, or AC Welder with Reduced Voltage Control.
Mild Steel
Effects of acute (short-term) overexposure to the gases, fumes, and dusts may include irritation of the eyes, lungs, nose and throat. Some toxic gases associated with welding may cause pulmonary edema, asphyxiation, and death. Acute overexposure may include signs and symptoms such as watery eyes, nose and throat irritation, headache, dizziness, difficulty in breathing, frequent coughing, or chest pain. The presence of chromium/chromate in fume can cause irritation of nasal membranes and skin. The presence of nickel compounds in fume can cause metallic taste, nausea, tightness of chest, fever, and allergic reaction.
Pre-existing Medical Conditions Aggravated by Overexposure: Individuals with allergies or impaired respiratory function may have symptoms worsened by exposure to welding fumes; however, such reaction cannot be predicted due to the variation in composition and quantity of the decomposition products.
Effects of chronic (long-term) overexposureto air contaminants may lead to their accumulation in the lungs, a condition which may be seen as dense areas on chest X-rays. The severity of the change is proportional to the length of the exposure. The changes seen are not necessarily associated with symptoms or signs of reduced lung function or disease. In addition, the changes on X-rays may be caused by non-work factors such as smoking, etc. Nickel and chromium (in some products) are considered carcinogenic. Long term overexposure to nickel fumes may also cause pulmonary fibrosis and edema. Overexposure to manganese compounds may affect the central nervous system, symptoms of which are languor, sleepiness, muscular weakness, emotional disturbances and spastic gait.
Stainless Steel
Electric arc welding may create one or more of the following health hazards:
ARC RAYS can injure eyes and burn skin.
ELECTRIC SHOCK can kill.
FUMES AND GASES can be dangerous to your health.
PRIMARY ROUTES OF ENTRY are the respiratory system, eyes and/or skin.
SHORT-TERM (ACUTE) OVEREXPOSURE EFFECTS:
WELDING FUMES - May result in discomfort such as dizziness, nausea or dryness or irritation of nose, throat or eyes.
IRON, IRON OXIDE - None are known. Treat as nuisance dust or fume.
MANGANESE - Metal fume fever characterized by chills, fever, upset stomach, vomiting, irritation of the throat and aching of body. Recovery is generally complete within 48 hours of the overexposure.
NICKEL, NICKEL COMPOUNDS - Metallic taste, nausea, tightness in chest, metal fume fever, allergic reaction.
CHROMIUM - Inhalation of fume with chromium (VI) compounds can cause irritation of the respiratory tract, lung damage and asthma-like symptoms. Swallowing chromium (VI) salts can cause severe injury or death. Dust on skin can form ulcers. Eyes may be burned by chromium (VI) compounds. Allergic reactions may occur in some people.
SILICA (AMORPHOUS) - Dust and fumes may cause irritation of the respiratory system, skin and eyes.
MOLYBDENUM - Irritation of the eyes, nose and throat.
LONG-TERM (CHRONIC) OVEREXPOSURE EFFECTS:
WELDING FUMES - Excess levels may cause bronchial asthma, lung fibrosis, pneumoconiosis or "siderosis."
IRON, IRON OXIDE FUMES - Can cause siderosis (deposits of iron in lungs) which some reseachers believe may affect pulmonary function. Lungs will clear in time when exposure to iron and its compounds ceases. Iron and magnetite (Fe3O4) are not regarded as fibrogenic materials.
MANGANESE - Long-term overexposure to manganese compounds may affect the central nervous system. Symptoms may be similar to Parkinson's Disease and can include slowness, changes in handwriting, gait impairment, muscle spasms and cramps and less commonly, tremor and behavioral changes. Employees who are overexposed to manganese compounds should be seen by a physician for early detection of neurologic problems.
NICKEL, NICKEL COMPOUNDS - Lung fibrosis or pneumoconiosis. Studies of nickel refinery workers indicated a higher incidence of lung and nasal cancers.
CHROMIUM - Ulceration and perforation of nasal septum. Respiratory irritation may occur with symptoms resembling asthma. Studies have shown that chromate production workers exposed to hexavalent chromium compounds have an excess of lung cancers. Chromium (VI) compounds are more readily absorbed through the skin than chromium (III) compounds. Good practice requires the reduction of employee exposure to chromium (III) and (VI) compounds.
SILICA (AMORPHOUS) - Research indicates that silica is present in welding fume in the amorphous form. Long term overexposure may cause pneumoconiosis. Noncrystalline forms of silica (amorphous silica) are considered to have little fibrotic potential.
MOLYBDENUM - Prolonged overexposure may result in loss of appetite, weight loss, loss of muscle coordination, difficulty in breathing and anemia.
MEDICAL CONDITIONS AGGRAVATED BY EXPOSURE:
Persons with pre-existing impaired lung functions (asthma-like conditions).
Brazing rods and fluxes
Inhalation of large amounts of particulates generated by this product during metal processing operations may result in irritation. Inhalation of copper oxide and zinc oxide fumes can cause metal fume fever. Initial symptoms of metal fume fever can include a metallic or sweet taste in the mouth, dryness or irritation of the throat, and coughing. Later symptoms (after 4-48 hours) can include sweating, shivering, headache, fever, chills, thirstiness, muscle aches, nausea, vomiting, weakness, and tiredness. Repeated over-exposures, via inhalation, to the dusts or fumes generated by this product during brazing operations may have adverse effects on the lungs with possible pulmonary edema and emphysema (lifethreatening lung injuries). Chronic over-exposure to Copper dust may cause tiredness, stuffiness, diarrhea, and vomiting.
Note: Metal fume fever is also causes by overexposure to galvanized welding fumes.
Tungsten: Not much to say here. Aside from tungtsen, it could contain thoria (2% thoriated), or Lanthana (1.5% Lanthanated) If dust is created while sharpening, use respiratory protection.
Lead: (from a pure lead msds)
Health Hazards Acute & Chronic: IRRITATING TO THE RESPIRATORY SYSTEM, SKIN, & EYES, WEAKNESS, VOMITING, LOSS OF APPETITE,UNCOORDINATION, CONVULSIONS, STUPOR, COMA.
Signs & Symptoms of Overexposure:
IF LEFT UNTREATED: WEAKNESS, INSOMINIA, HYERTENSION, IRRITATION TO SKIN & EYE, ANEMIA, METALIC TASTE, CONSTIPATION, HEADACHE, MUSCLE & JOINT PAIN, NEUROMUSCULAR DYSFUNCTION, PARALYSIS, ENCEPHALOPATHY. LEAD & ITS INORGANIC COMPOUNDS ARE NEUROTOXINS WHICH MAY PRODUCE PERIPHERAL NEUOPATHY.
Matt asked me to write a post here about welding safety. Since our hobby will involve metal fabricating (welding,cutting, grinding, and brazing) sooner or later, I was more than happy to oblige.
What I am going to post is a combination of my personal experiences, research, what I have learned, and most importantly NOT learned in trade schools and classes throughout the years. I will cover SAFETY issues only. Of course, if anyone has anything to add to this, please, feel free to do so! I also attached some pictures of welding shields, and respirators at the end.
First, I'd like to tell you a little bit about myself. My name is Rob and I'm 32 years old. Above all, I am a car nut! Since I have to be a (semi) responsible adult and keep my kids fed and the lights on, I get money by being a structural Ironworker and a certified weldor. I have been doing this for the better part of 15 years. My father is also a structural Ironworker, and was once a certified weldor also. I was 4 the first time I was in a fab shop, 10 the first time I picked up a cutting torch and a welding lead, 16 for my first "formal" welding class, 18 when I worked in a nuclear power plant the first time (20' beneath the reactor), and 23 when I took and passed both the New York City (destructive bend test) and New York state (non-destructive x-ray test) welding tests.
I'll stop boring you with details about my life now, and start boring you with safety!
The first thing you should know about, and probably the most important is the:
Material Safety Data Sheet or MSDS: According to OSHA, ALL materials and chemicals that can be found in the workplace are required to have an MSDS. This includes welding wire, tungstens,and argon,( I've even seen one for distilled water) OSHA also mandates that the employer keep copies of them on file for an employee (you) to review at their request without fear of reprisal. My suggestion, the next time you run to Lowe's to pick up a 2lb. spool of wire, READ that piece of paper that's folded up and taped to the back. Don't just throw it away. You can also find them here for free http://www.wmsds.com. Their selection is limited, they just have them for electrodes and filler metal.
Fire Extinguishers: Aside from a welding machine, the MOST important piece of equipment in a welding shop! These should be kept close to the area where the welding is being done. Depending on the process, you are dealing with a flame or an electric arc, and definitely molten metal. Also, if there is grinding going on, there are sparks involved. Any one of these things can start a fire! I've set myself on fire several times while welding. (sorry Matt, no one was around to appreciate it)
Protective Clothing: Natural materials like leather and cotton (yes I know cotton burns, but it doesn't melt like the synthetics do. and melting clothes is a whole lot worse than burning clothes) Jeans, long sleeve shirts, boots (leather, over the ankle, laced up with pant leg over them. When you drop a hot spark down your boot, you can't get it off fast enough. Trust me, I know) welding caps, jackets, and if need be, chaps. Also a good pair of leather gloves!( Mechanix gloves are synthetic. They melt!) Make sure you pick the right gloves for the job too. You don't want to try to tig weld with heavy arc welding gloves on, just like you don't want to try to arc weld with light tig gloves on.
Welding Shields: (The topic that started it all!) They range in price from $15-30 for you basic fixed lens child, up to $1000+ (yes that is one thousand) for an adjustable auto darkening with peripheral view and PAPR (I'll get into that soon enough) and with shades ranging from #5 up to #14. I do recommend the auto darkening shields (I have 2 of them. A Jackson that is nice and sturdy but a pain to adjust that I use at work, and a Miller that is a breeze to adjust, but the shield part feels a little flimsy for my tastes, that I use at home.) There are even full-face respirators with clip on welding Shields. They are bulky,hot, and heavy, but they provide a tremendous amount of protection. If you decide to invest in an auto-dark shield, make sure it is easily adjustable! And, when you first start out with it, set it at its darkest setting, and then work your way down until you can SAFELY see the weld area.
Other Eye Protection: Oxy/Acetylene cutting, welding and brazing, as well as grinding and cutting with a cut-off wheel(wizzer) does require eye protection, but not necessarily a welding shield. For torch work, a #5 shaded glass is recommended. They can be glasses, goggles, or even used in a welding shield. Cutting and grinding is a little different, because of the amount of sparks created. A clear face shield is suggested when doing this. Some employers now require it. I use an old 4"x5" fixed shield with only clear glass in it.
Ear/ Hearing Protection: It gets really loud when you're grinding or cutting with a wheel for a while. To keep from getting that ringing, soft foam earplugs work fine. Also, stray sparks and weld spatter CAN bounce into your ear canal. Trust me, it is really painful!! Foam earplugs will stop this from happening.
Respiratory Protection: OSHA assigns a PEL (Permissable Exposure Limit) to all known chemicals that could become a dust, fume, or vapor (dust and fumes are solids, vapors are liquids). These values are assigned for unprotected breathing, and are usually a weight per cubic meter of air (mg/m3). There are many types of respirators on the market that provide different levels of protection. There are also many different types of filters, each type protects you from a different type of nuisance.
Half face respirators- exactly as stated. Covers half of your face, offers no vision protection. Respiratory protection at the rate of 10x the PEL.
Full face respirators- Respirator covers the entire face offering eye protection. Respiratory protection at a rate of 100x the PEL.
PAPR (Powered Air Purifying Respirator)- Consists of a battery pack that straps to your waist that powers a fan that filters, then pumps the air to you. Makes it a little easier to breathe. DO NOT CONFUSE PAPR WITH FORCED AIR!!! THAT MISTAKE CAN KILL YOU!!!
Forced air respirator- Available in both half and full faced models. Consists of a remote compressor with filters and a hose that pumps the air to the facepiece. Two things to remember: 1. All equipment must be suitable for breathing air! 2. The air is only as good as the air where the compressor is set up.(don't set it up in your garage and think it will be ok to spray urethane paint in there!)
SCBA (Self Contained Breathing Apparatus)- Similar to SCUBA,however it is not rated for underwater use( SCOTT packs for the fire fighters). It consists of an air tank strapped to your back connected, by a hose, to the facepiece (almost always full face). Perfect for low oxygen, toxic, or IDLH (Immediately Dangerous to Life or Health) environments Obviously, the increase to the PEL is infinite. The only limiting factor is the amount of air in the tank.
Lead: Used as a body filler in quarter panel and A-pillar seams. In it's solid state, there is no danger. When melted (to remove it) it releases some fumes. However, when it is welded on (lead leaches into steel, so it is NEVER really gone), it is vaporized and a very high concentration of fumes are released. Respiratory protection is HIGHLY recommended. MAGENTA filters are used for lead protection!!
Compressed Gas Cylinders: If you MIG/TIG weld, or use an OXY/Acetylene torch set up, you will be using compressed gas cylinders.
Acetylene tanks: store Acetylene at 220 psi. It is flammable, but it is not explosive like propane is. As a safety, to prevent extreme pressure buildup in the event of a fire, Acetylene tanks have lead plugs on the bottom that will melt, leaking out the Acetylene.
High Pressure Tanks( Oxygen, Argon, CO2, etc.): These store gasses at a very high rate of pressure(2000-2200 psi when full). There is no safety measure like an Acetylene tank, so if exposed to fire, the tank could rupture and explode! Also, the valve of the tank is only brass, and therefore fragile. That is why these tanks have a steel cap to protect the valve in transport. Full, these tanks could take off like a rocket if the valve breaks off(2200 psi squeezing through a 1/4" hole)! My high school welding teacher said that he witnessed an O2 tank go through the hull of a ship!
Gasses
Argon- Used primarily as a shielding gas for MIG and TIG welding, either pure(mig welding aluminum) or mixed with other gasses such as CO2 (mig mild steel) and helium and CO2 (mig stainless steel). Also used to purge gas tanks for welded repairs (DO NOT TRY THIS AT HOME!!!) and to back gas stainless pipe or tube for mig and tig welding. Argon, being heavier than air, will collect in low, unventilated areas and displace all breathable air. From an argon msds:
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SECTION VI - HEALTH HAZARD DATA
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THRESHOLD LIMIT VALUE: ARGON IS AN ASPHYXIANT AND HAS NO THRESHOLD LIMIT VALUE.
EFFECTS OF OVER EXPOSURE: ARGON MAY INDUCE SUFFOCATION BY DILUTING THE CONCENTRATION OF OXYGEN IN AIR TO LEVELS LOWER THAN IS NECESSARY TO SUPPORT LIFE. EXPOSURE TO OXYGEN DEFICIENT ATMOSPHERES MAY PRODUCE DIZZINESS, NAUSEA, LOSS OF CONSCIOUSNESS, VOMITING AND DEATH. IMPAIRED MUSCULAR COORDINATION. DIMINISHED MENTAL ALERTNESS.
EMERGENCY AND FIRST AID PROCEDURES: REMOVE VICTIM TO AREA OF NORMAL OXYGEN CONTENT. SELF-CONTAINED BREATHING APPARATUS MAY BE REQUIRED TO PREVENT ASPHYXIATION. ASSISTED RESPIRATION AND SUPPLEMENTAL OXYGEN SHOULD BE GIVEN
IF THE VICTIM IS NOT BREATHING.
Helium- Used to fill ballons, make your voice funny, and mixed with argon and co2 for welding purposes. From the helium msds:
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SECTION VI - HEALTH HAZARD DATA
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THRESHOLD LIMIT VALUE: SIMPLE ASPHYXIANT
EFFECTS OF OVER EXPOSURE: ASPHYXIANT. SYMPTOMS OF FATIGUE, SLEEPINESS, LOSS OF COORDINATION, CONFUSION AND COLLAPSE MAY OCCUR. LIQUID CONTACT CAN CAUSE FREEZE BURNS.
EMERGENCY AND FIRST AID PROCEDURES: REMOVE VICTIM TO FRESH AIR. RESTORE AND/OR SUPPORT BREATHING AS NECESSARY. ADMINISTER OXYGEN IF AVAILABLE.
Oxygen- An oxidizer, used with acetylene for cutting and welding. Note: The air we breathe is roughly 20% oxygen. The range of oxygen that we need to survive is 17% up to 24%. Yes, too much can harm you just as much as too little. Also, pure oxygen should not be mixed with certain materials, such as oil or grease. the result could be explosive!
SECTION V - REACTIVITY DATA
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STABILITY: STABLE
INCOMPATIBILITY (MATERIALS TO AVOID): REACTS WITH EXPLOSIVELY WITH PHOSPHINE, HYDRAZINE, ETHERS, ALCOHOLS, HYDROGEN SULFIDE, HYDROCARBON, ETC.
HAZARDOUS DECOMPOSITION PRODUCTS: N/A
HAZARDOUS POLYMERIZATION: WILL NOT OCCUR.
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SECTION VI - HEALTH HAZARD DATA
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THRESHOLD LIMIT VALUE: N/A
EFFECTS OF OVER EXPOSURE: EXTENDED EXPOSURES TO O2 AT HIGHER PRESSURES MAY BE HAZARDOUS. A VARIETY OF CENTRAL NERVOUS SYSTEM EFFECTS MAY RESULT FROM BREATHING O2 GREATER THAN 2 ATM., SUCH AS DIZZINESS, IMPAIRED COORDINATION, VISUAL AND HEARING DISTURBANCES AND SEIZURES.
EMERGENCY AND FIRST AID PROCEDURES: REMOVE TO FRESH AIR.
Acetylene(dissolved)- Used at low pressures (less than 15psi) to cut, weld and braze.
From the msds:
Potential Health Effects
Inhalation : May cause anesthetic effects. In high concentrations may cause asphyxiation.
Symptoms may include loss of mobility/consciousness.Victim may not be aware of asphyxiation. Asphyxiation may bring about unconsciousness without warning and so rapidly that victim may be unable to protect themselves.
Filler metals, Fluxes, And Tungsten
This is where the really nasty stuff is! I'll break it down to the 3 most common metals that would be welded or brazed on a car, and then the fluxes as a general, and tungsten.
Note: When you see CHROMIUM listed, it can contain CHROMIUM VI. This is carcinogenic! If your wives/ girlfriends "made" you watch "Erin Brockovich", this is the same stuff!!!
Mild Steel: The most common metal on a car. Typical ER70S2 (MIG/TIG wire) wire itself contains any and all of :Aluminum, Carbon, Chromium, Copper, Iron, Manganese, Molybdenum, Nickel, Silicon, Titanium, Vanadium, Zirconium
Stainless Steel: Found in more exhaust systems these days. ER 3xx (308-347)series wire contains any and all of the following:IRON, MANGANESE, NICKEL, CHROMIUM, SILICON, MOLYBDENUM
Aluminum: Found in A/C systems and on more and more radiators contains any and all of the following: Aluminum, Magnesium, and Silicon
Brazing(low fuming bare and flux coated): Brass/Bronze rods used to join sheet metal with an oxy/Acetylene torch. Contains: Copper, Zinc, Tin, Manganese, Iron, Silicon
The flux coating contains any and all of the following: Boric Acid, Methacrylate/Aliphatic & Naphthenic Hydrocarbon Compound, Borax Glass
Flux covered SMAW (shielded metal arc welding) electrodes:
Mild Steel(7018, 6010, 9018,etc.,etc.) Contain any and all of the following: IRON, MANGANESE, ALUMINUM OXIDE, CALCIUM CARBONATE, CELLULOSE, MICA, SILICA, SILICON, TITANIUM DIOXIDE, FLUORSPAR, CHROMIUM, NICKEL, MOLYBDENUM, MAGNESIUM CARBONATE, SILICATE BINDERS
Stainless Steel and Cast Iron (E308L-16, E309L-16, E316L-16,etc.) Contain any and all of the following: IRON, CHROMIUM, NICKEL, CALCIUM CARBONATE, FLUORSPAR, MANGANESE, SILICA, TITANIUM DIOXIDE, SILICON, ALUMINUM OXIDE, MOLYBDENUM, COPPER, COLUMBIUM, TUNGSTEN, SILICATE BINDERS, ZIRCONIUM, MICA, STRONTIUM CARBONATE,ALUMINUM, MAGNESIUM, ANTIMONY TRIOXIDE, BARIUM CARBONATE
Aluminum (E4043) Contains all of the following: Aluminum, Silicon, Aluminum Fluoride, Lithium Flouoride, Magnesium Fluoride, Potassium Chloride, Potassium Fluoride, Sodium Chloride
Tungsten: Aside from tungtsen, it could contain thoria (2% thoriated), or Lanthana (1.5% Lanthanated)
Lead: Used as a filler from the 1920's up to the early 1970's. Usually a 70/30 mix (70%lead 30% tin)
Hazards
Aside from the standard "electric shock can kill" warning. There is the standard warnig that is on most products these days "WARNING: This product, when used for welding or cutting, produces fumes or gases which contain chemicals known to the state of California to cause birth defects (or other reproductive harm), and in some cases, cancer. (California Health and Safety Code 25249.5 et seq.)"
Also:
Radiation burns- Electric arc welding, whether it be arc, mig, or tig, producesan intense ammount of ultraviolet radiation and that causes burns on both the skin, and the eyes. On the skin, the symptoms of radiation burn is identical to that of a sunburn. On the eyes, somtimes called "welding flash" or "arc eye", the only way I can describe it is like someone threw sand in my eyes. Yes, I've been flashed before. The first time, the weldor was 50 feet away from me, and I didn't realize it untill about 10 hours later. What it is, is a third degree burn, or sunburn, on your corneas. You don't even know it's there. It does blister, and the blisters pop because of eye movements and blinking. IT HURTS!!!
Burns: You are dealing with fire, electric arcs, and molten metal. Even if you are wearing the right clothing, you could still get burned.
Other effects( by filler metal)
Aluminum
Short-term (acute) overexposure to welding fumes may result in discomfort such as metal fume fever, dizziness, nausea, or dryness or irritation of nose, throat, or eyes. May aggravate pre-existing respiratory problems (e.g. asthma, emphysema).
Long-term (chronic) overexposure to welding fumes may affect pulmonary function. Bronchitis and some lung fibrosis have been reported.
WARNING: This product contains or produces a chemical known to the State of California to cause cancer and birth defects (or other reproductive harm). (California Health & Safety Code Section 25249.5 et seq.)
Arc Rays can injure eyes and burn skin. Skin cancer has been reported.
Electric Shock can kill. If welding must be performed in damp locations or with wet clothing, on metal structures or when in cramped positions such as sitting, kneeling or lying, or if there is a high risk of unavoidable or accidental contact with workpiece, use the following equipment: Semiautomatic DC
Welder, DC Manual (Stick) Welder, or AC Welder with Reduced Voltage Control.
Mild Steel
Effects of acute (short-term) overexposure to the gases, fumes, and dusts may include irritation of the eyes, lungs, nose and throat. Some toxic gases associated with welding may cause pulmonary edema, asphyxiation, and death. Acute overexposure may include signs and symptoms such as watery eyes, nose and throat irritation, headache, dizziness, difficulty in breathing, frequent coughing, or chest pain. The presence of chromium/chromate in fume can cause irritation of nasal membranes and skin. The presence of nickel compounds in fume can cause metallic taste, nausea, tightness of chest, fever, and allergic reaction.
Pre-existing Medical Conditions Aggravated by Overexposure: Individuals with allergies or impaired respiratory function may have symptoms worsened by exposure to welding fumes; however, such reaction cannot be predicted due to the variation in composition and quantity of the decomposition products.
Effects of chronic (long-term) overexposureto air contaminants may lead to their accumulation in the lungs, a condition which may be seen as dense areas on chest X-rays. The severity of the change is proportional to the length of the exposure. The changes seen are not necessarily associated with symptoms or signs of reduced lung function or disease. In addition, the changes on X-rays may be caused by non-work factors such as smoking, etc. Nickel and chromium (in some products) are considered carcinogenic. Long term overexposure to nickel fumes may also cause pulmonary fibrosis and edema. Overexposure to manganese compounds may affect the central nervous system, symptoms of which are languor, sleepiness, muscular weakness, emotional disturbances and spastic gait.
Stainless Steel
Electric arc welding may create one or more of the following health hazards:
ARC RAYS can injure eyes and burn skin.
ELECTRIC SHOCK can kill.
FUMES AND GASES can be dangerous to your health.
PRIMARY ROUTES OF ENTRY are the respiratory system, eyes and/or skin.
SHORT-TERM (ACUTE) OVEREXPOSURE EFFECTS:
WELDING FUMES - May result in discomfort such as dizziness, nausea or dryness or irritation of nose, throat or eyes.
IRON, IRON OXIDE - None are known. Treat as nuisance dust or fume.
MANGANESE - Metal fume fever characterized by chills, fever, upset stomach, vomiting, irritation of the throat and aching of body. Recovery is generally complete within 48 hours of the overexposure.
NICKEL, NICKEL COMPOUNDS - Metallic taste, nausea, tightness in chest, metal fume fever, allergic reaction.
CHROMIUM - Inhalation of fume with chromium (VI) compounds can cause irritation of the respiratory tract, lung damage and asthma-like symptoms. Swallowing chromium (VI) salts can cause severe injury or death. Dust on skin can form ulcers. Eyes may be burned by chromium (VI) compounds. Allergic reactions may occur in some people.
SILICA (AMORPHOUS) - Dust and fumes may cause irritation of the respiratory system, skin and eyes.
MOLYBDENUM - Irritation of the eyes, nose and throat.
LONG-TERM (CHRONIC) OVEREXPOSURE EFFECTS:
WELDING FUMES - Excess levels may cause bronchial asthma, lung fibrosis, pneumoconiosis or "siderosis."
IRON, IRON OXIDE FUMES - Can cause siderosis (deposits of iron in lungs) which some reseachers believe may affect pulmonary function. Lungs will clear in time when exposure to iron and its compounds ceases. Iron and magnetite (Fe3O4) are not regarded as fibrogenic materials.
MANGANESE - Long-term overexposure to manganese compounds may affect the central nervous system. Symptoms may be similar to Parkinson's Disease and can include slowness, changes in handwriting, gait impairment, muscle spasms and cramps and less commonly, tremor and behavioral changes. Employees who are overexposed to manganese compounds should be seen by a physician for early detection of neurologic problems.
NICKEL, NICKEL COMPOUNDS - Lung fibrosis or pneumoconiosis. Studies of nickel refinery workers indicated a higher incidence of lung and nasal cancers.
CHROMIUM - Ulceration and perforation of nasal septum. Respiratory irritation may occur with symptoms resembling asthma. Studies have shown that chromate production workers exposed to hexavalent chromium compounds have an excess of lung cancers. Chromium (VI) compounds are more readily absorbed through the skin than chromium (III) compounds. Good practice requires the reduction of employee exposure to chromium (III) and (VI) compounds.
SILICA (AMORPHOUS) - Research indicates that silica is present in welding fume in the amorphous form. Long term overexposure may cause pneumoconiosis. Noncrystalline forms of silica (amorphous silica) are considered to have little fibrotic potential.
MOLYBDENUM - Prolonged overexposure may result in loss of appetite, weight loss, loss of muscle coordination, difficulty in breathing and anemia.
MEDICAL CONDITIONS AGGRAVATED BY EXPOSURE:
Persons with pre-existing impaired lung functions (asthma-like conditions).
Brazing rods and fluxes
Inhalation of large amounts of particulates generated by this product during metal processing operations may result in irritation. Inhalation of copper oxide and zinc oxide fumes can cause metal fume fever. Initial symptoms of metal fume fever can include a metallic or sweet taste in the mouth, dryness or irritation of the throat, and coughing. Later symptoms (after 4-48 hours) can include sweating, shivering, headache, fever, chills, thirstiness, muscle aches, nausea, vomiting, weakness, and tiredness. Repeated over-exposures, via inhalation, to the dusts or fumes generated by this product during brazing operations may have adverse effects on the lungs with possible pulmonary edema and emphysema (lifethreatening lung injuries). Chronic over-exposure to Copper dust may cause tiredness, stuffiness, diarrhea, and vomiting.
Note: Metal fume fever is also causes by overexposure to galvanized welding fumes.
Tungsten: Not much to say here. Aside from tungtsen, it could contain thoria (2% thoriated), or Lanthana (1.5% Lanthanated) If dust is created while sharpening, use respiratory protection.
Lead: (from a pure lead msds)
Health Hazards Acute & Chronic: IRRITATING TO THE RESPIRATORY SYSTEM, SKIN, & EYES, WEAKNESS, VOMITING, LOSS OF APPETITE,UNCOORDINATION, CONVULSIONS, STUPOR, COMA.
Signs & Symptoms of Overexposure:
IF LEFT UNTREATED: WEAKNESS, INSOMINIA, HYERTENSION, IRRITATION TO SKIN & EYE, ANEMIA, METALIC TASTE, CONSTIPATION, HEADACHE, MUSCLE & JOINT PAIN, NEUROMUSCULAR DYSFUNCTION, PARALYSIS, ENCEPHALOPATHY. LEAD & ITS INORGANIC COMPOUNDS ARE NEUROTOXINS WHICH MAY PRODUCE PERIPHERAL NEUOPATHY.