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January 1, 2001 Issue
January 15, 2001 Issue
January 1, 2001
Go Build a BoatBy Monte Rhodes
What is it about building boats? Why do so many of us have a need, or maybe even an obsession to build boats? They look really good for one thing. A nice dory or sailboat with a beautiful sheer line... poetry. Plus if you like to be on the water, or just like to messabout, a boat that you have built yourself adds much to the pleasure. Building a boat can give a great feeling of accomplishment, and not just for a completed boat.
For me, laying out fair lines on plywood, building nicely shaped forms that the boat will be built around, or cutting, shaping and joining interesting pieces of wood cause good feelings themselves. When I shape a piece that doesn't happen to have any edges that are square, and maybe one side is even curved, and it fits right where it's supposed to... not ecstasy but close.
I started building boats about four years ago (at the age of 60). My first one was a plywood lapstrake rowing dory. I did an OK job of it. Even though all of my non-builder friends thought it was wonderful, I saw all of the imperfections, of course. But the most interesting thing about building that boat is how much I became obsessed with working on it. I had worked with wood before, made a garage into a bedroom and bath, remodeled a bathroom, etc., but no building project made me feel as good as working on that boat.
As it started to come together, when the lines of the finished boat started to emerge, wow, what a feeling! I would wake up in the middle of the night, go out to the garage to see my boat and run my hands over it. My wife teased me about it, but I noticed that she liked how it was turning out as well, and she understood how I felt about building it. It was August in Texas, hot, humid, steamy, but did it bother me? Not a bit. A little sweat mixed with the epoxy didn't seem to make any difference. When the dory was finished it was nice to row and would draw a crowd on the launch ramp, but the best part was over so I sold it.
A Bolger/Payson Bobcat was my next boat. What a sweet boat! Mr. Payson's book, Build the Instant Catboat, was my constant companion. It took awhile to build, even with my boat building obsession. I got to learn how to make a mast round and how to fiberglass plywood, and it was my introduction to tack and tape (stitch and glue) type of boat construction. The end result was well worth the effort.
My wife came up with a great name, Jaguarundi, which is a rare Texas cat (feline type). Catboat, rare in Texas, get it? Jaguarundi looked great, beautiful sheer, unstayed mast, gaff rigged, and what a joy to sail. I have owned six or seven other sailboats in the past, including a Hobie 16 and a couple of small cruising boats, and Jaguarundi was up there with the best for handling and downright enjoyment. It sailed well with three adults and up to four or five kids. The kids loved to crawl around on the big deck and washboards while we were under way (wearing PFDs of course). But I got interested in paddling and sold Jaguarundi.
I've built a canoe and five kayaks since then. Some I've kept, some I've sold and some I've just given to friends. How many boats can a person use anyway? Paddling is fun, but building them ... I don't think I have to say much more about that.
Four of the five kayaks were built with the stitch and glue method, a good way to get a decent boat on the water in a relatively short time, fun and easy to do as well. Cut out the pieces, stitch them together, add a little epoxy and fiberglass tape and you have a boat.
My best boat building effort so far is my pride and joy, a strip built Guillemot sea kayak designed by Nick Schade. It was an absolute joy to build, cutting all those strips of cedar to fit into the grand design. And it handles so much better than any of my stitch and glue kayaks. There may be some stitch and glue designs that track and turn as well as my Guillemot, but I haven't paddled one yet. And talk about drawing a crowd... I hear, "Drop dead beautiful," and they sure aren't talking about that big metalflake trihull.
As soon as I finish my latest home improvement project I'm going to start on my next boat, a slightly modified $200 Sailboat by Dave Carnell. I'm going to use 4mm okoume instead of 1/4" ply, probably add a curved deck fore and aft for some rigidity, and make a big cockpit. I've been building it in my head for awhile now and am anxious to start shaping those pieces of wood and joining them together.
I hope that as you read these words you get some sense of how I feel about building boats, and how it could be for you. I'm sure that many readers of MAIB have the same obsession as 1. There is a lot of good advice around about what kind of boat to build and pitfalls to avoid so I won't get into that. Go build a boat, you'll love it.
Introducing HurricaneBy Compass Classic Yachts
We have purchased the molds for the Cape Dory Typhoon and have built a new boat called Hurricane based on her lines. The draft has been reduced to 20" and a centerboard added, making her easier to trailer. The topsides have been lowered by 4" giving her a less boxy profile. I have designed a traditional gaff rig, which lowers the center of effort and keeps her looks in line with our other classic yachts. Her cockpit is I I' long with full seat-ing for six adults and plenty of storage space. The Hurricane carries 850lbs of internal bal-last. She feels and sails like a 25 footer.
We will show the Hurricane for the first time at the Maine Boatbuilders' Show in March 2001 at Portland, Maine.
Merv Harmmatt, Compass Classic Yachts Inc., Box 143, South Orleans, MA 02662. (508) 255-5187
January 15, 2001
Safe BoatbuildingBy Dave Carnell
Chemicals are commonly perceived 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 boatbuilder. 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 for a safe workplace. I have summarized it all in four basic principles of handling hazardous materials. They are:
- 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 sinoke. 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 costs of your tools, but there are a lot of inexpensive fans and blowers around whose motors cannot spark. Box-type window fans and the small 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 are dangers of fire and explosion with the many flammable solvents and products used in boatbuilding. 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 solvent 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 boatbuilding shop. Before you use propane torches or other open 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 spark producers from the brushes of their motors.
If you must use protective equipment instead of ventilation to breathe clean 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 the 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, paints, adhesives, sealers, etc. off of your skin. Your hands are most exposed, but you may expose other parts of your body and not realize it, especially by spills on your clothing (including shoes). For most boatbuilding 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 going to be 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; especially 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 material s, but are so clumsy and so easily punctured or tom that they are not of much use. Medical examining gloves come both in latex and vinyl; the latex variety 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. All chemical reactions speed up as the temperature rises, including the reactions that cause bums, itching, rashes, or absorption through the skin. If you sweat as I do, it aggravates the whole situation. Look for loose-ftting 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 something on your clothes, change them. Clean your protective equipment every day. You are probably not going to have a safety shower, but a sink faucet or a garden 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 boatbuilding chemicals? You will, if you do not wash your hands and face thoroughly before that midmorning snack, refreshing cold drink, lunch, or cigarette. The 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.
These are the general rules for keeping out of trouble with hazardous chemicals. Let's take a look at specific materials, their hazards, and procedures for using them safely.
Wood Dust: Wood dust is the most commonly encountered chemical hazard in boatbuilding and perhaps the most hazardous. Over 300 varieties of wood have been reported to cause dermatitis. Hear-twoods are worse than sapwoods (probably because of the natural poisons they contain, which also make them more resistant to decay). The exposure limit is 5mg/m3 for all woods except western red cedar, which is 2.5mg./m3 (because one in 20 people is allergic to red cedar dust). These are exposures for 8hr. working days. The short time exposure limit is only 10mg./ m3. The physiological reason OSHA based the wood dust limit on is avoidance of respiratory effects.
OSHA noted that the International Agency for Research on Cancer classifies furniture manufacturing as a source of "confirmed human carcinogen" and carpentry as a source of "suspected human carcinogen" in people, not mice, rats, or guinea pigs. Cancer is caused by long-term exposure to an agent. With wood dust, as with nearly all of the chemicals regulated, OSHA concluded that avoiding exposures that can cause immediate acute effects will also protect against cancer over the long term.
How much dust is that? In a 20' by 20' by 10' high shop, a half teaspoon of fine wood dust distributed uniformly in the air would be a concentration of 5mg./m3, that is not much and is the reason you should always wear dust protection when sanding.
Lauan mahogany dust may be a bad actor, too. Dynamite Payson wrote me of his allergy to it, "I just can't breathe any of the dust without half choking." A friend of mine broke out in a rash all over his body with an accompanying fever after sanding a mold plug made of lauan.
There is no limit set on fiberglass dust, not because it is harmless, but because quantitative information needed to set limits is not available. All dusts are probably harmful and should be kept out of your lungs. In addition to its own effects, tobacco smoking aggravates the effects of some dusts, including coal dust, asbestos and radon decomposition particles.
Styrene: OSHA set the average 8-hr. exposure limit for styrene at 50ppm, (parts per "Ilion) to avoid narcotic effects. They set the short term exposure limit at 100ppin to prevent eye and upper respiratory irritation. Styrene's strong odor is detectable down to 0. Ippin if you have just come in from breathing fresh air. Although styrene is a possible human carcinogen, the limit set to avoid narcotic effects is more stringent than to avoid cancer based on currently available data. Polyester resins may contain 35% styrene.
Epoxy Resins: Most epoxy resins have no vapor problems. The hazard is possible sensitization by the hardeners from excessive skin contact. If you work cleanly with epoxy resins you should have no problems. If you become sensitized, which may cause rashes, dermatitis, or allergy reactions, by overexposure of your skin by careless and sloppy use, it is likely not to reverse and you may not be able to go back to using epoxies. Sensitization susceptibility varies greatly among people, but is not common. In general, the less hardener required in a recipe, the more likely it is to cause sensitization; that is, 10/1 mixes are most potent; 1/1, least.
I strongly prefer epoxy resins to styrene-containing polyester resins because the hazards of working with them are less and are much more easily manageable. In addition, they are superior engineering materials with respect to adhesion, reliability of curing, and compatibility with other materials, such as foams, in boatbuilding.
Sodium Hydroxide: Also known as lye or caustic soda,it is one of the most hazardous industrial chemicals. You may find it in teak cleaners, bleaches, or some paint removers. While most chemicals can be easily washed off with copious amounts of water, sodium hydroxide reacts rapidly with organic materials such as skin, flesh, and eyes. It causes them to gel and is absorbed into them so that it is extremely difficult to wash out. All the while it continues to bum. 1, and others I know, have been drenched with concentrated acids and washed them off in safety showers without injury. The victims I know of caustic spills are badly disfigured or dead.
Handle with extreme caution and wear the best eye protection you have.
Toluene: Toluene is a solvent widely used in paints, thinners, paint removers, and other solvent-based materials boatbuilders use. The 8hr. average limit for exposure is set at 100ppm in air, with the short-term limit only slightly higher at 150ppin. Avoidance of narcotic effects is the reason for the limit, with concern to avoid even brief exposure to high concentrations. Like most solvents, toluene defats the skin and makes it sensitive to dermatitis. For gloves, only Buna-N and nitrile rubber are reasonably impervious to toluene.
Acetone: Acetone is commonly used for cleaning up. Don't use it if you value your skin. It defats the skin and is absorbed through it. It is also probably the most flammable material commonly found in a boat shop. Waterless hand cleaners are better cleaners for your hands.
Diisocyanates: These compounds are components of linear polyurethane paints used for slick hull finishes. They appear to be the most potent sensitizers around. They are also cross-sensitizers with other materials. The sensitization shows up as respiratory problems which may not go away after exposure stops. The OSHA 8hr. limit for toulene diisocyanate is 0.005ppin (5 parts per billion) and the short-term limit is only 0.02ppm. This means that you spray linear polyurethane paints only with a full suit of protective clothing and an external fresh air supply. No respirator cartridge will protect you. Isocyanates are not cyanides, which are another class of toxic chemicals not found in the boat shop.
Natural Materials: Some people have the idea that only synthetic compounds are harmful and that naturally occurring materials are harmless. Have you ever tumbled in a bed of poison ivy or tangled with a Portugese man-of-war? We have seen that wood dust may well be the worst hazard boatbuilders encounter because of its toxic nature and its presence in nearly all boatbuilding operations. Turpentine is as toxic as most solvents and stuffing a rag wet with it in your pants pocket can give you a chemical bum in a hurry. Pine tar, like all materials that have been overcooked contains pyrenes, strong carcinogens. If your diet is heavy in char-broiled steaks and blackened redfish, you are being exposed to pyrenes.
Chemical Myths: There are various chemical myths that have been repeated many times. The wildest one I know is that mixing household ammonia and household bleach produces mustard gas. Mustard gas is a compound of carbon, hydrogen, chlorine, and sulfur. Ammonia is a compound of nitrogen and hydrogen. Bleach (sodium hypochlorite) is a compound of sodium, chlorine, and oxygen. Creation of the carbon and sulfur needed for mustard gas would be an accomplishment far exceeding any nuclear fission or fusion known to man. All our energy problems would be forever solved. The truth of the matter is that mixing bleach and ammonia (both are 5% solutions in water) generates a little heat and boils off mostly ammonia fumes.
The best all-around advice is a combination of statements from boatbuilding product literature: "None of our products is safe. They cannot be made safe. Work cleanly." Get material safety data sheets (MSDS) when you buy boatbuilding materials. They are difficult for someone without chemical background to understand, but there is always useful information on how hazardous the materials are, how to handle them safely, what protective equipment is needed, first aid and contacts for help in an emergency situation.
Always stop and think about how you are doing a job and how you may get into trouble.
How To Get Help From Material Safety Data Sheets: The information required in Material Safety Data Sheets is generally specified by OSHA. The specifics, the detail, and the manner of presentation are left up to the manufacturers and distributors; for the same chemical, different sources will publish MSDS that are quite different in forniat though the essential data will be the same.
The sheets may be incomprehensible at first glance to persons without some knowledge of chemical and physical principles and the descriptive jargon of toxicology and chemical hazards. The information is presented in a standard order and the boatbuilder should look for:
- Distributor: There will be at least an emergency telephone contact for medical help.
- Material Identification: The chemical nature of the material. Numerical ratings of the hazards in terms of health, fire, and reactivity. These will be numbers from 0 to 3 (3 is the greatest hazard). Generally, health and fire are your greatest concerns.
- Components: The lesser materials and impurities present.
- Physical Data: Information on color, odor, taste, and quantitative data which can tell you a lot about hazards of working with the material.
- Vapor pressure: This number can tell you a great deal about the ventilation requirements and fire hazards of working with the material. It is given in mmHg (millimeters of mercury) at 20 degrees C. (68 degrees F). Values for typical materials are: Water, 17; acetone, 181; styrene, 6; epoxy resin, less than 0.1, toluene, 22. These are saturated vapor pressures, what you have in the vapor space over the liquid in a sealed and part full can. The higher the vapor pressure, the greater the possible toxic exposure, fire hazard and the better ventilation required.
Protect Your Eyes! David W. Carnell, 322 Pages Creek Dr., Wilmington, NC 28411
(David admits to having 40 years' experience with Dupont safety meetings.)
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