Some of the tools and materials used to build this canoe or any other strip built water craft can be very dangerous if not used properly. Always read and heed manufactures’ warnings.
It might be a leap of faith, but I am going to assume that if you are embarking on building a project of this size, you have probably used power tools before. That being the case, you should be fully aware of the potential to lose an eye or multiple digits from your hand with the slightest misstep.
I do not think I will ever forget that day in high school shop class when one of my classmates got his clothing caught in a spinning lathe project. He managed to escape without major injury, but it scared the heck out him and everyone that saw it. Even experienced wood workers sometimes find out the hard way that a momentary lack of attention can result in a very painful lesson in just how fast things can go wrong.
The likelihood an accident can be minimized by following the guidelines below:
ü Read the safety section of your tools’ owner’s manual.
ü Make sure your work area is well lighted.
ü Provide adequate ventilation.
ü Keep your work area clean.
ü Make sure tools are in good repair.
ü Always make a test run to ensure there is adequate outfeed support and space.
ü Control possible sources of distraction.
ü Wear appropriate clothing.
ü Use personal protective equipment.
ü Do not work past your limits. If the board is too big, get help. If you are tired, quit.
Remember the old adage, “An ounce of prevention is worth a pound of cure.” The bottom line is that preventing accidents is no ones responsibility except yours.
Special considerations are required when working with epoxy. I make no assumptions regarding previous experience in this area. For many readers of this book, this will be the first time you have had the opportunity to work with epoxy and fiberglass on a large project. For this reason, I will go in to some detail regarding the safe use and handling of the products.
The problem with substances such as epoxy is that the hazards are not readily apparent and may not manifest themselves for many years. So while it is easy to recognize the danger of a carbide tipped blade whirling around at 10,000 rpm, the dangers posed by epoxy and fiberglass are not as obvious. So please take the time to read the following.
The following safety guidance is based on information provided by WEST SYSTEM on their web site at www.westsystem.com. While serious health problems associated with epoxy use are uncommon, failure to follow manufactures’ instructions can result in undesired consequences. Epoxy resins and hardeners are comprised of a number of chemical ingredients of varying proportion and toxicity which in small amounts are not generally harmful. However, when mixed, resin and hardener becomes hot and generates toxic vapors. These include carbon monoxide, oxides of nitrogen, ammonia, and possibly some aldehydes. Most epoxy related health problems are minor, but they can cause discomfort. Fortunately, these problems are preventable.
Problems are usually a result of overexposure. There is a safe exposure level for most substances. The more toxic the substance, the lower that level will be. Overexposure occurs when the safe exposure level is exceeded. Each individual has a different threshold. Your immune system and overall health will influence your tolerance of a substance.
Hazardous substances enter the body by skin absorption, inhalation or ingestion. The route for a particular substance depends on its physical characteristics and how it is normally used. The risk of exposure to resin, hardener and mixed epoxy is greatest when they are liquid. As it solidifies, epoxy and its components are less likely to enter the body. Once epoxy is fully cured, the chemical ingredients form a non-hazardous solid.
Skin contact is the most common means of exposure to resins and hardeners. Even minor skin contact, if repeated often enough, can cause chronic health problems. Exposure by inhaling vapors is unlikely, because epoxy products evaporate slowly. However, the risk increases when ventilation is inadequate or when the products are heated. Ingestion is least likely. If you swallow epoxy, drink large quantities of water, DO NOT induce vomiting. Hardeners are corrosive and can cause additional harm if vomited. Call a physician immediately.
The health effects from overexposure to epoxy include dermatitis, allergic dermatitis, and respiratory irritation.
Dermatitis
The most common reaction is contact dermatitis, or skin inflammation. Both epoxy resin and hardener can cause acute contact dermatitis. Discomfort can be severe, but usually disappears after stopping contact with the irritant. Repeated skin contact with resins and hardeners may also cause chronic contact dermatitis, which is usually milder but longer lasting. If left untreated for long periods it can progress to eczema, a form of dermatitis that can include swelling, blisters and itching. Partially cured epoxy sanding dust, if allowed to settle on the skin, can also lead to contact dermatitis. This is especially true when the dust comes in contact with perspiring skin.
Allergic Dermatitis (Sensitization)
Allergic dermatitis is a more serious problem but less likely. Allergic dermatitis is when the body hyper reacts to an allergen. You are more susceptible if you have fair skin, if you have already been exposed to other sensitizing substances, if you have allergies, or are under stress. Allergic reactions to epoxy can result in irritated skin or respiratory problems. Irritated skin is by far the more common of the two. Usually, it appears much like a reaction to poison ivy and may include swelling, itching and red eyes. Just as with poison ivy, the irritation can be mild or severe, acute or chronic.
You may become sensitized to epoxy after many exposures or just one. It could take ten days of exposure, a month, or even years. It is best to avoid all exposure because you cannot know ahead of time how much you can tolerate before you become allergic.
Once sensitized, additional (and sometimes increasingly severe) reactions become likely upon future exposures, even to tiny amounts of epoxy. It is very difficult to prevent recurrences. Stop using the product if you develop a reaction. Resume work only after the symptoms disappear, usually after several days. When you resume work, improve your safety precautions to prevent exposure to epoxy, its vapors and sanding dust. If problems persist, discontinue use and consult a physician.
Respiratory Irritation
Breathing highly concentrated epoxy vapor can irritate the respiratory system and cause sensitization. At room temperature, epoxy vapors are unlikely to be highly concentrated. However, if you are already sensitized to epoxy, exposure to low concentrations of epoxy vapors can trigger an allergic reaction. At warmer temperatures and in unventilated spaces, the epoxy vapor levels increase.
Never breathe the sanding dust of partially cured epoxy. Epoxy chemicals remain reactive until they have cured. Serious health problems can result from breathing sanding dust from epoxy that is not fully cured. When you inhale these dust particles, they become trapped in the mucus lining of your respiratory system. The reactive material can cause severe respiratory irritation and/or respiratory allergies. Even if the epoxy is fully cured, never sand glass impregnated epoxy without protection. It should go without saying that glass dust is pretty bad for you as well.
Preventing Health Problems
You can prevent health problems caused by epoxy, or any hazardous materials, by limiting your exposure. This means using respirators, eye protection, protective clothing and gloves when handling hazardous materials. You can protect yourself from epoxy vapors by using a respirator with an organic vapor cartridge. The approved respiratory protection against epoxy dust, wood dust and nuisance dusts is a dust/mist mask or respirator. Barrier skin creams can provide added protection. Additionally you should adhere to the following guidelines.
ü Set up a safe shop. Install effective ventilation. This can range from expensive, high-tech air-filtration and exhaust systems to the basic floor or window fans. When you can’t adequately ventilate your workspace, wear an approved respirator with an organic vapor cartridge.
ü Always wear a dust/mist mask or respirator when sanding epoxy, especially partially cured epoxy.
ü Avoid ingesting epoxy. Wash thoroughly after handling epoxy, especially before eating or smoking.
ü Keep your workshop clean to avoid incidental contact. Avoid touching door handles, light switches and containers when you have epoxy residue on your gloves, because you may touch them later without gloves on.
ü Always wear disposable surgical style gloves when handling epoxy. Also apply a barrier cream to your hands before working with epoxy just in case the gloves give way.
ü Where a Tyvek smock when applying epoxy. Tyvek smocks are made of a DuPont plastic fabric that epoxy does not stick to and are generally considered disposable. They are commonly used in clean room environments to minimize contamination from the dust of street cloths. If you cannot get your hands on a Tyvek smock, at least wear old cloths or make a tunic from a large trash bag.
Dealing with Contact
If you do get resin, hardener or mixed epoxy on your skin, remove it as soon as possible. Resin is not water-soluble. Use a waterless skin cleanser to remove resin or mixed epoxy from your skin. Hardener is water soluble; wash with soap and warm water to remove hardener or sanding dust from your skin. Always wash thoroughly with soap and warm water after using epoxy, removing amine blush, or sanding epoxy. Never use a solvent or vinegar to clean your skin.
Epoxy will quickly soak through cloths and if you do not remove the clothing immediately you may find that you will have to wear them, or at least a piece, for a very long time. Use skin cleanser or vinegar to remove any epoxy from your clothes. If you cannot completely remove it from your clothes, do not continue to wear them. If it is mixed epoxy, you may wear the clothes again after the epoxy has completely cured. NEVER use solvents such as acetone to remove epoxy from your skin. The solvent will penetrate deep in to your skin and carry the epoxy with it right in to your blood stream.
If epoxy gets in your eyes, immediately flush them with water under low pressure for 15 minutes. If discomfort persists, seek medical attention.
Cleaning Up Spills
Clean up spills with a scraper, collecting as much material as possible. Follow up with absorbent towels. Use sand, clay or other inert absorbent material to contain large spills. DO NOT use sawdust or other fine cellulose materials to absorb hardeners. Clean unhardened resin or mixed epoxy residue with vinegar. Follow all safety warnings on solvent containers.
Disposal
DO NOT dispose of hardener in trash containing sawdust or other fine cellulose materials. The heat from the curing epoxy can cause them to spontaneously combust. To safely dispose of empty resin and hardener containers, puncture a corner of the can and drain the residue in to the appropriate new container of resin or hardener. Do not dispose of resin or hardener as liquids. Mix and cure waste resin and hardener (in small quantities) to make a non-hazardous inert solid. While the leftover mixed epoxy cures, set the container aside where you can monitor it. Use a fan to disperse vapors and direct them away. Dispose of the solid mass only after it has completely cured and cooled. Follow federal, state or local disposal regulations.
Curing Epoxy
CAUTION! Containers of mixed epoxy can get hot enough to ignite surrounding combustible materials
The chemical reaction that cures mixed epoxy is exothermic, or heat generating. If left to cure in a contained mass, such as in a mixing pot, it can generate enough heat to melt plastic, burn your skin or ignite surrounding combustible materials. The larger or thicker the epoxy mass, the more heat generated. A 100-gram (3.5 ounce) mass of mixed epoxy can reach 400°F. Place containers of mixed epoxy in a safe and ventilated area, away from combustible materials.
To prevent heat buildup, transfer epoxy from the mixing pot to a roller pan or other wide, shallow container. Fill large cavities with epoxy in multiple layers rather than in a single, thick layer.
Curing epoxy gives off hazardous fumes. Cured epoxy can emit similar vapors when heated too much. This can happen when you use a flame to release epoxy-mounted hardware. To reduce this risk, use just enough heat to release the hardware. Only as a last resort should you use a flame to burn epoxy from hardware. If you must do so, work in a well-ventilated area.
Spraying Epoxy
Do not spray epoxy because the health and safety risks are enormous. As epoxy leaves a spray gun nozzle, it is reduced to tiny droplets (spray mist). You can easily inhale epoxy that is suspended in the air. It can cause extensive lung damage and other health problems. The spray mist can settle on your skin, causing sensitization and allergic reactions and it can settle on your eyes, injuring them.
Using solvents to thin the epoxy for spraying adds to the health and safety risks. These hazards are similar to those of any spray painting operation, involving both health and flammability concerns.
Dusts from woods commonly used on strip canoes, such as cedar, redwood, and mahogany can cause allergic skin and respiratory reactions. Wood saps and oils contain irritants that can be released as vapors when the wood is heated by the friction of working with the wood such as sawing.
Dusts from glass, carbon and similar fibers, coming from cutting and handling glass tape or cloth, or from sanding or grinding a fiberglass composite are dangerous because of their shape, which makes them difficult to expel from the lungs. Use these materials only with adequate ventilation and appropriate respiratory protection, such as an approved particulate dust mask.
Preventing Overexposure to Dusts
The following sensible shop suggestions may help to reduce exposure to epoxy dusts, wood dusts and fillers.
ü Use personal protective equipment if you handle wood you suspect that you may be particularly sensitive to.
ü Sand only in shop areas with adequate ventilation. If dust levels in your shop are high, or if you are sanding in a confined space for a long time, wear an approved dust mask.
ü When you have a choice, use a cutting tool, a chisel or plane, rather than an abrading tool, a polisher or sandpaper.
ü Use wet, rather than dry, sanding techniques on epoxy. When sanding fresh epoxy wear protective clothing, eye wear and an approved dust mask.
ü When you sweep your floor, wear a dust mask. It is safer to vacuum because less dust goes in to the air.
ü Use dust collectors on major dust producing machinery.
Summary
Use common sense. The more informed you are about the products you use, the better off you’ll be. Master basic health and safety principles and take responsibility for seeing them through. When it comes to setting the rules and work practices of your shop, your health and safety are in your own hands.
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