Heating galvanised reinforcing bar

[Ten Hammers]

Greetings. There will be folks that disagree with me. I have worked in facilities that had questionable health and safety issues. I also am a Veteran. I personally happen to agree with Mssrs Rich, Ted and Smoothbore , Glenn and others on the caution side.

My personal experience shows that welding galvanized with a mig and using a shop vac to suck the fumes is 100% smarter that breathing the fumes. Just don't get too close to suck the shielding gas. My experience also shows that forges and galvanized work. Just not for me anymore. Nor do Plasma's used in a shop that does not have a fan blowing across the area of the cutting operation into a LARGE open door.

There will be folks that have no experience in many issues and perhaps become injured in one fashion or another. It seems that some will not recall events that have happened to them personally and again take risks because of either past good experience in building or repairing regardless of the risks. Some will continue to take part in personal self medications programs. Some survive some don't.

There will be acute symptoms and there will chronic issues. There will be another chance and there will be death. At my stage of the game, I have more experience that some. I have lost friends from the chronic issues of more than one thing. Chemicals and airborne ingestion were the bulk of the problems although alcohol and drugs also played a part in some. I also have known folks that neither drank nor smoked that died from the chronic issues involved in airborne ingestion, mostly of welding issues. I once had an HR woman tell me that I couldn't smoke in the welding shop due to insurance regulations. I asked if it was a fire issue and she said no, it was regarding employees health and smoking. I asked if she had read the MSDS on a 44 lb. spool of E70S6 welding wire. Her reply was no.

Your own personal actions are based on your own thoughts. The thing is, these are your thoughts and your actions. My experience has shown that airborne ingestion of galvanized fumes and plasma dust are no longer tolerated by me personally. < that is a period. Do I still weld and use the plasma? Of course. Do I weld galvanized ? Not a chance. Acid will indeed remove coatings before welding.

I use rebar for re-enforcing concrete and nothing else. There is plenty of steel available for forging and welding.

I have seen and experienced the effects of galvalume poisoning. I feel lucky to have survived. I have observed the chronic issues in more than one death resulting from galvalume poisoning. I also lost a friend here from it (the resulting chronic result). Everybodys own mileage will vary. I have never been on a ship in the Bering Sea but I HAVE been on the flight deck of an aircraft carrier.

[pkrankow]

...
My personal experience shows that welding galvanized with a mig and using a shop vac to suck the fumes is 100% smarter that breathing the fumes. Just don't get too close to suck the shielding gas. My experience also shows that forges and galvanized work. Just not for me anymore. Nor do Plasma's used in a shop that does not have a fan blowing across the area of the cutting operation into a LARGE open door.
...

Is the shop vac outside? Doesn't do much good if it isn't

I have a coupler that can hook my shop vac hose to PVC or iron pipe so my vac can be quite a ways away. It is useful for many things (and I will add this to the list) This coupler can be bought at most big box stores, it is the rubber step adapter.

http://www.lowes.com/pd_37045-20097-9068711_4294857471_4294937087_?productId=1085001&Ns=p_product_price|0&pl=1&currentURL=%2Fpl_Shop%2BVacuum%2BAccessories_4294857471_4294937087_%3Fpage%3D2%26Ns%3Dp_product_price|0&facetInfo=

The downside of having a length of PVC pipe hooked to a shop vac with dust passing though it is static buildup...lots of it. I have been put on my butt by it once (after cleaning sawdust), so be careful.

I have used my 10ft wand for cleaning the ceiling on my great room, and found it short. I have also used it to clean gutters, but it isn't very good at that if the contents are wet.

Phil

[Ten Hammers]

Is the shop vac outside? Doesn't do much good if it isn't

" Do I weld galvanized ? Not a chance "

[Glenn]

There has been some very good information posted. I think it is time to site references, MSDS sheets, case studies, etc.

The following references are all from the Safety Section of IForgeIron on similar subjects

first reference here

and here

Reference 1

Reference 2

Reference 3

Reference 4

Reference 5

There may be more as the discussion comes up on a regular basis

[Glenn]

Another reference



IForgeIron Blueprints
Copyright 2002 - 2007 IFORGEIRON, All rights reserved.

BP0170 Toxicology
by Woody Hanson

Foreword:

Usually my ramblings take on a humorous tone, but there is nothing funny about being poisoned. With that in mind, I will try to pass on to you some of the things I have learned in over 30 years of dealing with chemicals. According to "Casaretti and Doull's Toxicology: The Basic Science of Poisons," "All substances are poisons; there are none which are not a poison. Yet on a daily basis we expose ourselves and others to a myriad of toxic substances as if we were honor graduates on the "Scratch and Sniff School of Chemistry". Repetition does not equal right, just because we have done certain things with chemicals before and got away with it, does not mean that there are not adverse consequences associated with our behavior. In addition to poisoning yourself, you also may be bringing toxic substances home from the shop and sharing them with your families and children. We seem to operate on the premise that if it don"t blow up in our face and kill us on the spot the first time, whatever we are doing must be safe and acceptable but all the while we are trying to stifle that little annoying nagging voice in the back of our minds that is screaming "what the heck are you thinking". There are Governmental Regulations that dictate safe practices when handling chemicals in the workplace, but since most of us in the Blacksmithing Community are either hobbyists or a self employed single person operation, we do not fall under the requirements of these regulations. That doesn't mean we have to be unaware, uninformed and unprotected. If you choose to be, that is your prerogative but give a little thought to who will provide for your family if you are unable to work because of illness or death. It is said that ignorance is bliss, but in this case what you don't know can hurt you.




What effect a toxic substance will have:

The three factors that determine what effect a toxic substance will have on the human body are:

1. Dose: The concentration and quantity of the chemical to which you were exposed.

2. Duration: How long were you exposed.

3. Route of Entry: How did the substance enter the body.



Routes of Entry:

There are four routes of entry for a toxic substance to enter the body:

1. Inhalation where be breath in the vapors, fumes or finely divided particles of the substance. Once the toxic substance has entered our respiratory system, it can cause us harm in a number of ways. Either damaging the respiratory system itself, or by passing through the lungs and into the blood where it can either affect the blood or other organs of the body.

2. Ingestion where the substance enters our body via the mouth. We don�t usually go out and taste toxic substances, but I have witnessed people putting their finger into a substance thought to be antifreeze and tasting it. Most cases of poison by ingestion are caused by poor personal hygiene habits, i.e. failing to wash our hands and face after leaving the shop and before eating or drinking. Eating and drinking in the shop area. And also by smoking or chewing tobacco without washing your hands. We get our fingers into everything from pie to poison and the next thing you know then end up in our mouth and rarely do they go through soap and water first.

3. Absorption where the substance contacts the skin and either damages the skin at the point of contact or is absorbed directly through the skin and passes into the blood stream where it can travel throughout the body and damage other organs.

4. Injection no one I know of has loaded a syringe full of poison and gave himself a shot, but in our work environment there are numerous sharp things with which we come in contact. If a sharp object is contaminated with a toxic substance and it penetrates the skin, you have just been injected. This is probably the least common way of chemical poisoning, but it is probably the most common way of developing a galloping infection that takes massive doses of antibiotics to cure.



Personal Protective Equipment:

You don't have to spend a fortune on PPE, but every shop should be equipped with the minimum necessary to afford adequate protection. The first thing in your PPE arsenal should be information. Get a Material Safety Data Sheet for every chemical in your shop. You will probably balk at this and think you don't need ones for the stuff you deal with on a daily basis. You are wrong! Did you know that there are at least 4 different carcinogens in gasoline. Get a MSDS for every chemical in you shop, put them in a 3 ring binder and then READ the MSDS before you handle the chemical. The MSDS cannot protect you if it is sitting on the shelf collecting dust. Remember that welding rods have chemicals in them so get a MSDS for them too. All you have to do to get one is ask for it when you purchase any material.

Next read the label on the container. They usually list some of the ingredients, but not always and usually have some safety precautions for handling and using the chemical. Remember that chemical companies are in the business of selling chemicals, not providing for your safety and well being. When regulations on use and disposal of 1-1-1 Tirchloroethane became very strict, I saw containers relabeled calling the 1-1-1 Trichloroethane Methyl Chloroform same stuff, just a different and correct name.

Once you are informed of the nature and hazards associated with the substances you use, it will be easy to assemble the minimum PPE that is necessary to protect yourself. This should include the following:

1. Respirator either full face or half face. Remember that one size does not fit all. When you purchase the respirator, have the supplier give you a fit test to determine what size fits you the best. You will also need filter cartridges what cartridges are necessary will be determined by what are dealing with. You may need several sets of cartridges to protect you from an array of chemicals. Clean the respirator and store it and cartridges in a tightly sealed plastic bag when not in use. This will keep it clean and help to extend the life of the cartridges. Replace cartridges when you began to smell contaminant through them.

2. Rubber Gloves and Apron if you are handling and working with corrosive materials, this is a must. When I say rubber, what you will probably end up with is some man made fiber, but be sure to tell your supplier what materials you expect the equipment to protect you from.

3. Chemical Splash Goggles these differ from goggles meant to protect you from flying objects in that they have indirect venting that does not allow liquids to enter through the vents.

4. Soap and Water a great amount of chemical contamination can be eliminated if we simply wash our hands and face before eating or drinking anything and when we leave the shop for the day.



Effects of Chemical on the Body:

1. Acute exposure to high concentrations of a chemical over a short period of time where there is rapid onset of the symptoms of chemical exposure the symptoms usually dissipate after the+ person is removed from the source of exposure. This is not to say that acute exposure cannot be life threatening, depending on the chemical, one acute exposure can be fatal.

2. Chronic exposure to chemicals over a long period of time where symptoms chemical exposure do not manifest themselves immediately. The chronic effects sometimes take years to develop. Chronic effects can be accumulative, and exposure to certain chemicals can have both an acute and chronic effect on the body.

Systemic Toxicity Exposure to a toxic substance can produce a local effect, or have a systemic effect. An example of a local effect would be skin contact with a corrosive material. The material burns the skin at the point of contact. If quick action is taken and the corrosive removed or neutralized, the effect would be a localized burn. If prompt action is not taken, the material can penetrate the skin and enter the blood stream or cause other internal damage. This would be considered a systemic effect.

The individual physiological systems of the body can be adversely affected in several ways. When a toxin adversely affects the human body, it does so in one or more of the following ways:

1. Pulmonary Toxins These substances affect the respiratory tract. From a basic point of view, a pulmonary toxin is an asphyxiant. Asphyxiants can be broken down as either as either simple asphyxiants or chemical asphyxiants. A simple asphyxiant displaces the oxygen in the air and causes injury to the body by oxygen deficiency. Chemical asphyxiation occurs with the actual destruction of the cells within the lungs. This leads to fluid buildup within the lungs which is referred to as pulmonary edema.

2. Hemotoxins These are a broad category of toxins that affect the circulatory system. Certain toxins can inhibit the ability of the blood to absorb oxygen and transport it within the body. Other toxins adversely affect the white blood cells or they can attack the bone marrow where red blood cells are produced. Others actually destroy red blood cells and some affect the electrolyte balance.

3. Neurotoxins These affect the central nervous system and peripheral nerve cells. Neurotoxins can inhibit operation of the central nervous system by binding to a certain part of a nerve cell or some actually destroy nervous system cells. Eventual death from the effects of exposure is a possibility.

4. Receptor Toxins These affect specific "target organs" or systems within the body. These would include:

. . . . A. Hepatotoxins Chemicals that can cause damage to the liver

. . . . B Nephrotoxins Chemicals that have a toxic effect on the kidneys.

5. Cytotoxins Chemicals that adversely affect anything they come in contact with. i.e. corrosives.

6. Teratogens Adversely affect the development of the fetus. i.e. Organic Mercury Compounds.

7. Mutagens Cause changes in the genetic materials in the nucleus of cells in a way that can be transmitted during cell division. These substances can cause a mutation. i.e. Benzene, Ethylene Oxide and Hydrogen Peroxide. 8. Carcinogens:Substances that are capable causing tumors. Substances that cause cancer. The effects of exposure to these substances may not appear for years.



Hazards of Various Chemicals:

At last count there were in excess of 25,000 chemicals that were known to be hazardous to humans. There is no way that I could possibly list all of them along with there hazards so I will attempt to list some of the more common chemical families and the general hazards associated with them. Keep in mind however, that there will be other hazards associated with some specific chemicals in addition to those listed for a specific chemical family.

Hydrocarbons All hydrocarbons are central nervous system depressants. That is when they enter the body they produce an anesthetic effect. They put the brain to sleep. You are all probably aware that ether (a hydrocarbon) has long been used as an anesthetic. Ethyl alcohol, i.e. Jack Daniels Bourbon, is also a hydrocarbon and you are well aware of the effects it has on the human body. In addition to the anesthetic effect produced by these substances, many chemicals in this family are carcinogens the BTEX group, Benzene, Toluene, Ethyl Benzene and Xylem, are prime examples of this. All of the preceding 4 chemicals can be found in gasoline.

Primary routes of entry for hydrocarbons to enter the body are inhalation and skin absorption with the exception of ethyl alcohol where ingestion is the preferred route of entry. In addition to effects on the central nervous system, exposure to hydrocarbons can have detrimental effects on various other organs of the body including the kidneys, liver, heart, lungs and blood.

Chlorinated Hydrocarbons In addition to the effects on the central nervous system mentioned above for Hydrocarbons, nearly all Chlorinated Hydrocarbons are carcinogens. Further, depending on their chemical makeup, they can have adverse effects on other organs of the body, usually the liver or kidneys. Carbon Tetrachloride damages the kidneys while 1-1-1 Trichloroethane damages the liver.

Primary routes of entry are inhalation and skin absorption. Some common sources of Chlorinated Hydrocarbons are brake cleaner, electrical contact cleaner, penetrating oil and paint remover.

Dust is a common hazard that is overlooked by most of us. Dust particles that are less than 5 micron in size penetrate to the deepest part of the lungs where they damage the alveoli. Dust particles in this size range include coal dust, silica dust and asbestos particles. In addition, the dust from sanding various woods is toxic to some people. For example Cocobolo and some horn materials that are used as handle material by knife makers. In addition, dust or sandings from heavy metals can be

The only route of entry for dust that is of any consideration is by inhalation. Dusts can also enter the body by ingestion if eating and or drinking is allowed in the work area.

Heavy Metals, especially Lead, Zinc, Nickel and Cadmium are extremely toxic to the human body. Arsenic, another heavy metal which is more rarely found is a deadly poison. The greatest hazards faced by blacksmiths from these substances is the breathing of the fumes from the molten metals when welding or soldering. Lead is the basic ingredient in solder. Lead free solders may contain Cadmium as may certain types of welding rod. Arsenic is commonly used in treating wood to make it insect and rot resistant. Keep that in mind the next time you are looking for kindling to start the fire in your forge.

In addition to the hazards listed above, Nickel is also a sensitizer which upon repeated exposure can cause an asthma like reaction if inhaled

Common routes of entry are inhalation of the fumes from the molten metals and to a lesser extent, ingestion of metal dusts by eating, and drinking in the work area.

Isocyanates are an extremely toxic group of chemicals they are usually found as the catalyst in two stage paints such as DuPont Emron. They are respiratory system sensitizers. While this may sound rather benign, it can be deadly. As a person is exposed to these chemicals, the respiratory system becomes sensitized to the chemical. This may be as a result of one acute exposure or to several repeated exposures. Sensitivity varies with the amount of exposure and the individual. Once the respiratory system becomes sensitized, any further exposure will produce an allergic reaction that may be as mild as symptoms of a cold to as severe as anaphylactic shock and death.

Route of entry is inhalation.

Acids are used for various processes when working metals, among them are pickling metal to remove the scale, etching Damascus blades to bring out the pattern and in some cases, quenching the metal to harden it. When one thinks of acids, the most immediate hazard that comes to mind is that of it�s corrosiveness to skin there are other hazards associated with these materials that are less well known. The fumes from acids can damage the respiratory tract. Some like Hydrofluoric Acid, which is found in aluminum brightener, will give a mild corrosive burn to the skin at the point of contact, penetrate the skin and go directly to the bones it leaches the calcium out of the bones. Washing with water will not remove this acid once it has penetrated the skin. An ice cold solution of a chemical called Zepherin is needed to neutralize this type of acid. In addition, with large burns from this acid, the solution may have to be injected to effect neutralization. Other hazards of acids include the formation of toxic and or flammable gases when in contact with certain other substances in addition they may form explosive compounds when mixed with the right chemicals. They can also cause spontaneous combustion when mixed with certain other materials. Many acids are more powerful oxidizers than pure oxygen.

Primary routes of exposure are inhalation of the vapors and skin contact.

Bases like acids, bases are used in various metal working applications either to clean metals or to produce various patinas on certain metals. Bases like acids can be corrosive to the skin.

Primary routes of entry are inhalation of the vapors or fumes or skin contact.

Gases Generally in metalworking we deal with 3 different types of compressed gases.

1. Flammable Gases Two of the more common gases associated with metalworking are Acetylene used for welding and cutting operations, and Propane or LPG used as fuel for forges as well as in welding and cutting operations. In addition to the obvious flammable hazard inherent with these gases, they can displace the oxygen in the air and cause asphyxiation. A few words of caution about Acetylene are never enough. This gas is decidedly unstable. In fact it is so unstable that it is dissolved under pressure in Acetone in the cylinder to keep it from exploding. It is flammable in air in concentrations from 2.5% to 100%. Another hazard of this gas is its' ability to deteriorate the hoses of the welder. If the tank is not shut off and the hoses drained it can cause the hoses to deteriorate. If this happens when the shop is unattended, the entire contents of the tank can be leaked into the shop. When the shop is reoccupied, the first person to make a spark or turn on a light switch gets to play "Mr. Roberts does Hazmat". "Hi boys and girls can you say KABOOM?" "Can you say butt first through the wall?"

2. Non-Flammable Gases Various Non-Flammable gases are used as shield gases in welding. The most common are Carbon Dioxide (CO2) Argon, Nitrogen and Helium. Some shield gases are a mixture of two or more of the fore mentioned gases. The primary hazard of these gases is that they displace the oxygen in the air. They are odorless and can collect in confined spaces or poorly ventilated areas and cause asphyxiation. One or two breaths in an oxygen deficient atmosphere is usually enough to cause unconsciousness.

3. Oxidizers Oxygen used in welding and cutting operations is a powerful oxidizer. While it does not burn, it causes other materials to burn with savage intensity. Nomex, a flame retardant material used in firefighter clothing, burns like a gasoline soaked rag in an oxygen enriched atmosphere. Exposure to pure oxygen can cause some materials to spontaneously combust. Other chemicals not normally thought of as oxidizers are much more powerful oxidizers than pure oxygen. Nitric Acid and Sulfuric Acid are extremely powerful oxidizers. Some of the Halogens, (Chlorine and Fluorine for example) while containing no oxygen are extremely powerful oxidizers in addition to being poison gases. They will cause things that do not normally burn to ignite and burn, or form explosive compounds when mixed with other chemicals.

Primary route of entry for gases is inhalation although the high pressure hazard should not be ignored. Gas under pressure can be injected through the skin.

Poisons Some of the common poisons found around the average shop or garage are insecticides. Most of us are well aware of their inherent hazards and exercise some degree of caution when using and handling them. It is the less than obvious poisons that you need to worry about. I once saw a can of penetrating oil that listed only two ingredients, Carbolic Acid and 1-1-1 Trichloroethane. Carbolic Acid�s proper name is Phenol, a skin absorbable POISON. I have already addressed the hazards of 1-1-1 Trichloroethane above. If you take nothing else away from reading this document, take this: READ THE LABEL, THEN GET THE MSDS AND READ THAT. Chemical companies are in the business of selling chemicals not looking after your health and welfare. Most of them have been vaccinated against scruples and ethics do don�t expect them to go to any great lengths that are not mandated by law to protect or inform you of the hazards associated with their particular products.

Chemical

Group

Compounds

Target Organs

Potential Health Effects

Aromatic Hydrocarbons

Ethyl Benzene Toluene, Xylene

Benzene,

Commercial solvents

Commercial solvents Blood, Bone Marrow, CNS. Eyes Respiratory System, Skin, Liver, Kidneys

CNS (Central Nervous System)

All cause central nervous system depression decreased alertness, headaches, sleepiness, loss of consciousness. Benzene suppresses bone marrow function causing blood changes. Chronic exposure can cause Leukemia. Other hydrocarbons can become contaminated with benzene during the distillation process.

Halogenated Aliphatic Hydrocarbons

Carbon
Tetrachloride, Chloroform, Ethyl Bromide, Ethyl chloride,
Ethylene Dibromide, Ethylene Dichloride, Methyl Dhooride,
Methyl Chloroform, Methylene Chloride, Tetrachloroethane, Trtrachloroethylene (Perchlorethylene), Trichlorethylene, Trichlorethane,
Vinyl Chloride
Common solvents CNS, Kidneys, Liver, Skin

CNS (Central Nervous System)

Kidney changes: Decreased urine flow, swelling (especially around eyes0 anemia.


Liver changes: Fatigue, malaise, dark urine, liver enlargement, jaundice. Vinyl chloride and several others in this group are known carcinogens.

Heavy Metals Arsenic, Beryllium, Cadmium, Chromium, Lead, Mercury Wide variety of industrial and commercial uses Multiple target organs and systems including: Blood, Cardiopulmonary, Gastrointestinal, Kidneys, Liver, Lungs CNS and Skin

CNS (Central Nervous System)

All are toxic to the kidneys. Each heavy metal has its own characteristic symptom cluster. For example, lead causes decreased mental ability, weakness, (especially hands). Headaches, abdominal cramps, diarrhea, and anemia. Lead can also affect the blood forming mechanism, kidneys and the peripheral nervous system. Long term effects also vary. Lead toxicity can cause permanent kidney and brain damage; Cadmium can cause kidney or lung disease. Chromium, beryllium, arsenic and cadmium have been implicated as human carcinogens. Herbicides Chlorophenoxy compounds: 2-4-D, 2-4-5-T, Dioxin which occurs as a trace contaminant in these compounds poses the most serious health risk Vegetation control Kidneys, Liver, CNS and Skin

CNS (Central Nervous System)

Chlorophenoxy compounds can cause chlorachne, weakness or numbness of the arms and legs and may result in long term nerve damage. Dioxin causes chloracne and may aggravate existing liver and kidney diseases. Exposure to Agent Orange which was primarily a mixture of 2-4-D and 2-4-5-T has caused a multitude of diseases including some forms of cancer and Adult onset Diabetes.
Organochlorine Insecticides Chlorinated ethanes: DDT,
Cyclodienes: Aldrn, Chlordane, Dildrin, Endrin,

Chlorocyclohexanes: Lindale Pest Control Kidneys and Liver, CNS

CNS (Central Nervous System)

All cause acute symptoms of apprehension, irritability dizziness, disturbed equilibrium, tremors and convulsions.
Cyclodienes may cause convulsions without any other initial symptoms.
Chlorocyclohexanes can cause anemia. Cyclodienes and chlorocyclohexane cause liver toxicity and can cause permanent kidney damage. Organophosphates Organophosphates:
Diazinon, Dichlorovos, Dimethoate, Trichlorfon, Malithion, Methyl Parathion, Parathion
Carbamates:
Aldicarb, Baygon, Zectran Pest Control Liver, Kidneys All cause a chain of internal reactions leading to neuro-muscular blockage. Depending on the extent of the poisoning, acute symptoms range from headaches, fatigue, dizziness, increased salivation and crying, profuse sweating, nausea, vomiting, cramps and diarrhea, to tightness in the chest muscles, twitching and slowing of the heartbeat. Several may result in rapid onset of unconsciousness and seizures. A delayed effect may be weakness and numbness in the feet and hands. Long term permanent nerve damage is possible. Polychlorinated Biphenyl�s (PCBs)  Widely used in industry. In transformer oils for one. Liver, CNS (Speculatively) Respiratory System (Speculatively) and Skin Various skin ailments, including chlorachne; may cause liver toxicity. Possible carcinogen.

After word This is not meant to be an all inclusive definitive document on such a complex subject as Toxicology, but rather to draw attention to some of the more common toxic hazards we may become exposed to in our day to day metal workings. This is also meant to be a living growing document which will be added to and updated from time to time as the need arises or as questions and comments from readers are received.

The people who read this can generally be categorized into 3 groups:

* The first are the ones that will read this document and say "Gee, I didn't know that, I better do something to protect myself."

* The second are the ones that will say "that's interesting" and continue on as they have in the past.

* The third are the ones that will say "I have always done it that way and I ain't dead yet" and if they have the opportunity, the will challenge me on every point I have tried to make. To the last group I say please don't. I have heard it all before and your argument has no validity. I operate on the premise that it is ok to be incredibly stupid if you are the only one that knows. If you argue with me, your secret will be out, and I will tell everybody.

Addendum To Toxicology

Chemicals that are marginally dangerous in there liquid state can get very lethal when heated and converted into a gaseous state. Burning plastics, produce cyanide gas, and is why firemen wear SCBA (self contained breathing apparattus) when the fire is out, and there is just a little smoke. Plasma torches vaporize the metals they are cutting into very fine particles that are easily ingested and work their way into clothing. Irnsrgn





As Junior Strasil (Irnsrgn) so aptly pointed out, as the chemical changes its' state of matter from solid to liquid and liquid to gaseous, the hazards associated with the material generally increase. The changes in the state of matter are usually due to a rise in temperature. When heated, chemicals can simply vaporize and disperse in the air, they can breakdown into their various components, or they can change into other much more hazardous substances. For instance, when heated, Freon changes to Phosgene Gas. This is the same Poison Gas that was used in World War I and is still used as a fumigant in grain elevators. The same thing happens with Carbon Tetrachloride.



When two or more chemicals are mixed together reactions can occur that range from merely interesting to toxic to explosive. Even some common household chemicals when mixed together can produce very hazardous reactions. Household bleach when mixed with ammonia forms Nitrogen Trichloride Gas. This gas is deadly if inhaled and extremely explosive if it reaches a source of ignition. Hydrofluoric Acid, a common ingredient in aluminum brightener, when mixed with any form of an alkali evolves Hydrogen Fluoride Gas which is extremely toxic. Remember that it is a common practice to use alkalis to neutralize acids and vice versa, but in this case, the result of that reaction is deadly.



Other common chemicals that are found around our shops and garages have the ability to spontaneously combust. Most of these are in a family called Organic Peroxides. These are chemicals, usually a flammable solvent that has the peroxide group attached to it. All Organic Peroxides have a Self Accelerating Decomposition Temperature (SADT). Once they reach this temperature, they decompose. Some merely off gas vigorously, some ignite and burn quietly and others explode. These materials have all that is necessary to start a fire built into them. They have the fuel, a flammable solvent, Oxygen, the Peroxide Group, and when they reach their SADT, they light their own match. You might think you would have to search far and wide to find something as dangerous at these but that is not the case. You may have some of them in our shop or garage right now. Methyl Ethyl Ketone Peroxide (MEKP) always explodes at 140*Â F. It is the hardener for fiberglass resin. If you have fiberglass in your garage or shop, you have a small tube of MEKP. If it reaches 140 degrees it will explode. That small amount will not blow up your shop or garage, but it may start the fire that will burn it down. The hardener for body putty, Bondo, is a little more energetic. Benzyl Peroxide explodes at 90* F. It is best to keep this stuff in the refrigerator.

[Glenn]

I agree making people aware of dangers. I don't agree with effectively lying to them concerning what we know about the dangers, in order to scare them beyond what the facts support.

part of this post has been clipped

That does not mean it's a good idea to burn zinc, especially without taking any precautions. It isn't. But it's a bad idea mostly because it'll make you feel awful for a few days, and because we're not sure what the long term effects may be -- not because it provably *WILL* kill you, no matter what. At least give people enough respect to lay out the known facts, to speculate responsibly about dangers that may not yet be fully understood, and to let them make up their own minds about how much risk they're comfortable with. People who aren't willing to accept any risk should not be involved in blacksmithing. Or life, for that matter.

Matt, thank you for keeping us grounded and on track as we will continue to provide information and education.

[MattBower]

Great resources there, Glenn. Thanks. Woody's Blueprint was especially informative.

[macbruce]

I welded galv just this summer (wet wannabe) and the lightning nearby gave me far greater pause than the galv I was welding......Outside. Ventilation is the key, you put yourself in an enclosed space like Pawpaw and the atmosphere goes toxic in a hurry.....I've also done allot of sandblasting with the dreaded silica sand and still do.Outside. I prefer windy days to carry dust away from me and wear a dust mask. A risk I'M willing to take and I choose to take calculated risks all the time.I could sit here and list allot more, point is if you are taking risks and don't know it you're in trouble already and It's only a matter of time.Even though this galv thing is #1 at the department of redundancy department It can't hurt if some Newbie sees it for the first time.......

[Steve Sells]

I posted a harsh reply about zinc on the blade forum and had people obviously start telling me to shut up that Zinc aint all that dangerous.

I think some people are not worried, and they are Idiots..... and maybe them sucking in Zinc fumes is a good way to remove them from the gene pool. Not all people are smart WmHorus too bad

[Travis Covington]

The best solution is don't do it. I don't care what the argument is we should never advise anyone to take a risk with galvanize. It can and will cause heavy metal poisoning. I know I have gone thru testing for it. Luckily I don't have it but have the simptums and they are no fun. I do refuse to weld galvanize or stainless without ventilation now. I try to learn from my mistakes.

[macbruce]

The best solution is don't do it. I don't care what the argument is we should never advise anyone to take a risk with galvanize. It can and will cause heavy metal poisoning. I know I have gone thru testing for it. Luckily I don't have it but have the simptums and they are no fun. I do refuse to weld galvanize or stainless without ventilation now. I try to learn from my mistakes.

Well which is it, Don't ever do it, or it's ok with ventilation... ..I say the dangers are minimal if you take correct precautions... better yet get rid of it first with an outdoor acid wash........I'd like to take this opportunity to advise everyone here to play with fire. B)

[clinton]

So it is good to say avoid using galvanised material. Also as I tried to make a point of is avoid using rebar for anything other than what it was intended to do- reinforce concrete

[glen56]

dead right ted and john ,ted hats off mate ,hard to look at gear and always try to help,branding is a thing that runs off the back now(with me ) if you know something to save folk get it on ,like you say folk just are unaware,like gal and coal ,too late down the track,take it easy ,glen

[jeremy k]

This has de-railed from the original question on the first post. There is plenty of posts about the hazards of gavanized mat'l, on many other threads and dedicated threads. The original question is not about this, but about problems with bending.

[MattBower]

That's a fair point, Jeremy, but he did get several answers to his question.

[Travis Covington]

Well which is it, Don't ever do it, or it's ok with ventilation... ..I say the dangers are minimal if you take correct precautions... better yet get rid of it first with an outdoor acid wash........I'd like to take this opportunity to advise everyone here to play with fire.

I'm trying to say if you don't have the training or proper equipment leave it alone. A minimal danger is too much. Metal prices are high but not enough that anyone should have to take a risk. The outdoor acid wash is a good idea. Actually this should have gone in this direction because he is using heat on galvanize even though the question was different. You can never have too many cautions about safety. Life is too short for that.

[macbruce]

I'm trying to say if you don't have the training or proper equipment leave it alone. A minimal danger is too much. Metal prices are high but not enough that anyone should have to take a risk. The outdoor acid wash is a good idea. Actually this should have gone in this direction because he is using heat on galvanize even though the question was different. You can never have too many cautions about safety. Life is too short for that.

Ok, Let's get back to post #1..........."Heated some short gal reo lengths (hot dipped) for a mate (well ventilated and protected)" Sounds as if Old Boiler knows what the risks are and what he is doing and Took the necessary precautions. When I'm say welding on galv and I can't remove it, it's a given that the piece be adequately ventilated or it's on to plan b. When I first started welding I knew nothing about this and made myself a tad sick a time or two. The welding school I went to never mentioned it at all.

The school of hard knocks isn't always a catastrophe. Informing others of the dangers isn't the same as advising anyone to do anything, but if they do, they'll do it smarter..........

[Old Boiler]

I agree with all precautionary replies.
It was outside with the wind blowing towards the forge. That is, the front of the forge.
I won't be doing it again.
Now I'm more worried about the yellow residue on the refractory.

Jim.

[MattBower]

That's zinc oxide. Inhaling enough of it is what causes metal fume fever. I'd clean it out. A damp rag will probably do. It makes good sunscreen and diaper cream! Just kidding. (I mean, it is used for those things, but I'm not suggesting you should do that with the stuff in your forge.)

[glen56]

good on you ted hats off mate

[Rangerdave]

Very informative post. Thanks to all for their opinions/experience. As for me I'm stayin away from it. I want to enjoy life and to do that being sick or dead doesn't appeal to me.

[glen56]

mate thats why brilliant places like iforgeiron are very special source of info ,there are so many gifted folk at your command ,and like the old saying 'what dousn't kill you makes you stronger 'XXXX that dousn't apply when dealing with gear that you have no idea about,ranger dave glad to hear that from you ,take it easy,glen