Shop Tips » Working With Epoxy and Fiberglass
Safe Boatbuilding (Part 1) by Dave Carnell
By Dave Carnell [The guys at MAS Epoxies turned us on to Dave's excellent safe-boatbuilding essay, and it is used here with Dave's permission.]
Chemicals are commonly conceived as a small class of nasty dangerous materials when, in fact, the universe is completely chemical and every event from creation's "big bang" to the thrill a beautiful boat evokes is the result of a chemical reaction.
Any human activity has risks and no material we work with is harmless. Building and maintaining boats safely requires knowing the risks and hazards and working with respect, not fear. This is not easy for the amateur or small professional boat builder. His shop is dusty and poorly ventilated. He does not have clean, reliable, proper protective equipment and may not use what he has. He uses a whole mix of potentially hazardous materials about which he has little practical, understandable safety information.
Understanding is the important part of reducing risks and hazards.
We have to know "why we do what we have to do" for a safe workplace. I have summarized it all in four basic principles of handling hazardous materials:
- Protect Your Eyes!
- Don't Breathe Them!
- Don't Get Them On You!
- Don't Eat Them!
Protect Your Eyes
Wear at least safety glasses whenever you handle chemical materials and whenever you work with hand tools or machines. A chemical splash or a fragment thrown by a tool can blind an eye. Please protect your eyes. How would you work without them!
Don't Breathe Them
Don't breathe the vapors (fumes) of materials you are using. Don't breathe dust or smoke. If you smell anything you are working with you need better ventilation or protective equipment. Pay attention when you first smell something; your nose quickly becomes insensitive to even strong odors and then you may no longer be aware of your exposure.
Ventilation is the best way to prevent exposure. Working outside in a breeze is natural ventilation. It can be excellent, but can also fool you if the breeze bounces off your work and carries fumes back to you.
You start thinking about mechanical ventilation and the first stated requirement is explosion-proof motors. The price of that kind of equipment is higher than the cost of your tools, but there are a lot of inexpensive fans and blowers around whose motors cannot spark. Box-type window fans and all centrifugal blowers all use shaded-pole motors, which have the starting winding wired in permanently and no starting switch to make a spark. The "breeze-box" window fans are especially good for small shop ventilation. They are inexpensive, lightweight, move large volumes of air, and can be easily positioned to ventilate most situations.
Try to arrange the fan so that it pulls fresh air past you, over the work, and away from your work area. While designed to run in the vertical position, they operate horizontally as well. Working inside a boat, you can lay the fan over a hatch pointed away from you and the work and pull out the vapors while pulling fresh air in.
There is danger of fire or explosion with many flammable solvents and products used in boat building. Before vapor concentrations in your whole shop would reach the flammable limit, you would be unconscious (maybe dead) from the toxic effect. Flammable (explosive) concentrations exist only close to the flammable liquid or in special situations such as dense vapors flowing along a floor to an ignition source like a pilot light or a motor.
Good ventilation reduces the likelihood that flammable vapor concentrations can occur anywhere in your shop. Smoking is out of place in any boat building shop. Before you use propane torches or other flames make sure all flammable liquids are sealed up out of the way. Consider also that your stationary power tools spark each time you turn them on and many portable power tools are continuous sparkers from the brushes of their motors.
If you must use protective equipment and not ventilation to breathe dean air, a dust mask is the minimum protection, but a dust cartridge is better. Always wear a dust mask or respirator when sanding or grinding any material; wood, fiberglass, resin, metal. Wear dust protection when handling fine powders. Protection against vapors requires cartridges that chemically absorb the vapors. Be sure the cartridge is the right kind and be sure it is effective.
Test effectiveness by putting respirator on, and breathing near a source of the vapors; you should not smell any. If you start the job with a good cartridge, it may become loaded while you are working and your nose may not detect the gradual leakage of vapors. Good ventilation is the best control.
Don't Get Them On You
Keep all solvents, sealants, etc. off of your skin. Your hands are most exposed, but you may expose other parts of your body and not realize by spills on your clothing, including shoes. For most boat building situations, impervious gloves would appear to be the perfect solution, but there are problems with gloves.
Different chemicals require gloves of different materials for best protection. The kind of glove required is hard to pick when so many safety data sheets say to use "appropriate" or "impervious" gloves. Many of you are buying gloves in your drugstore, supermarket, or hardware store.
- The latex or rubber glove made in Malaysia or some other remote country is reasonable protection against epoxy resins and acetone, but not good with polyester resins, toluene, lacquer thinner, and most paint removers.
- Vinyl gloves will protect against epoxy resins, but are poor with most solvents; esp. acetone. Heavier gloves of rubber, neoprene, or nitrile rubber give better protection but are more difficult to work in and are much more expensive.
- The thin disposable gloves of polyethylene are resistant to most materials but are so clumsy and so easily punctured or torn that they are not of much use.
- Medical examining gloves come both in latex and vinyl; the latex offers protection and they are relatively easy to work in, but for me the tight fit makes my hands sweat profusely even in cool weather.
All protective equipment should be kept clean, as clean as your underwear. Pulling on dirty protective clothing can give you a head start on trouble. Wash the outsides of dirty gloves thoroughly with warm soap and water before taking them off. At least, don't stick the dirty gloves in your pocket to contaminate your clothing and skin.
If your gloves or hands are dirty when you put the gloves on, or if material is absorbed through the glove, the gloves then aggravate the exposure by keeping the material in close contact with your skin and by increasing the temperature of your skin. Chemical reactions speed up as the temperature rises, including the reactions that cause burns, itching, rashes, or absorption through the skin. If you sweat as I do, it aggravates the whole situation. Look for loose-fitting gloves with a flock lining.
Any time you get a chemical on you, wash it off thoroughly with soap and water. The standard first aid procedure for chemical spills on the body, especially in the eyes, is to flush thoroughly with water for at least 15 minutes (a long time). If you spill some on your clothes, change them. Clean your equipment every day. You probably aren't going to have a safety shower, but a sink faucetor a hose always ready to turn on is an essential piece of safety equipment. If you do not have fresh water, salt water is fine.
Don't Eat Them
Who would eat boat-building chemicals? You will, if you do not wash your hands and face thoroughly before that midmorning snack, refreshing drink, lunch, or cigarette.
Best practice is to not eat or store your food in the work area. Then wash up before you take a break to eat or drink. Chemical plant workers are more concerned about washing their hands before they go to the bathroom than afterwards.
Continue to part 2 . . .