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©2008 Charles Plesums
Austin Texas USA
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There are a number of environmental issues in "green," all lumped together. Some involve the use of resources (even before the woodworker is involved), some involve the environmental impact of the woodworking shop (factory), including minimizing and recycling waste, good use of energy, and low "outdoor" pollution (dust and chemicals). Still other concerns involve the end user environment - often as monitoring indoor pollution (chemical emission), and product safety.
This summary is based on ongoing readings, and a day-long course (oriented to furniture factories).
Although there are concerns about many hazardous chemicals, in the United States, factory and end-user issues often revolve around the emission/discharge of formaldehyde. How much should be allowed? None would be good, but people create/emit small amounts of formaldehyde. If NONE is the answer, then we have to eliminate all people. Oops, maybe we don't want to go that far. Formaldehyde is a useful ingredient in, or byproduct produced by, glue and finishes. But after Formaldehyde is used/created, it dissipates. So one consultant pointed out that practically any product could pass the most strict formaldehyde test if they were allowed to sit in an open warehouse for a month before use. (The manufacturing people in the audience hooted that option out as impossible, but it may be a good option for a solo woodworker, or be enough to reassure our customers.)
How much formaldehyde is "allowable?" 80 parts per million (ppm) of Formaldehyde in the atmosphere was considered noticeable pollution in years past. The FEMA trailers bought for housing after hurricane Katrina had 800 to 1000 ppm (after they baked in the New Orleans sun, sealed closed, for a long period. No wonder people living in the trailers were getting sick). So if 80 ppm is starting to be a problem, what level is safe if we can't have zero? The level was set at 0.05 ppm. Boy is that low. Where does it come from?
I love the "green" plywood. It costs 5-10% more than imported plywood, but I consider it a premium quality plywood for several reasons. It is domestically made. The show veneer is much thicker - it can even be sanded. The alternative, most of the imported plywood at my lumber yard, is "combi-core" which puts a man-made layer between the show veneer and the traditional core plies (The imported show veneer is so thin that the grain of the next layer can show through). But the combi-core layer, like untempered masonite, is so weak that I cannot surface glue anything to the plywood - I must use a tenon, biscuit, rabbet, screw, or other device to get through that lousy layer to attach anything. Oh, incidentally, there is no formaldehyde in the plywood glue. Okay. I guess that should make me happy.
If you use plywood, you may also use edge banding. Nobody at this conference could suggest a type of edge banding adhesive that was formaldehyde-free. So if you use "green" plywood, how will you hide the edges? None of the factory people could consider gluing a strip of hardwood on plywood, using conventional wood glue (too slow and expensive). But I am slow, and if you want to avoid edge banding, I would be glad to use conventional wood glue for a hardwood strip. (I also wouldn't worry about normal edge banding after a week or so, but that is your choice).
Normal nitrocellulose lacquer is not good enough for kitchen use... I have dropped it as my primary finish. Catalyzed lacquer works like regular lacquer, but over the following weeks and months, the catalyst causes cross-linking (something that makes the chemists and finishing experts smile and go ooohhhh). But that cross linking (in lacquer and conversion varnishes) is a chemical reaction that creates ... yup... formaldehyde, even if there wasn't any in the original finish. Sure, it will dissipate in a month or two, but not soon enough for the factory boys. "Why don't you use water base acrylic lacquer like I do, with NO evil emissions?" I asked. "Because it doesn't work in the finishing machines in the factory." "Because it can't be cured in seconds with infrared light or microwaves." Then the discussion moved to the problems of balancing the fast cure speed with the durability and appearance of the finish. A long tail is good. What's that? A finish that cures (or cross links) slowly is, in general, a better finish but may emit chemicals over those weeks.
As the factory folks discussed the "UV coatings" that are cured by ultraviolet lights, they admitted that they were radically different materials than used in small shops, that there were almost no emissions after the material was "dry", that the "cross linking" (the smile and oohhh part) occurred in the UV ovens. But the materials were frightfully expensive, and created environmental issues in the factory.
Does everyone have this problem? No. Another country was used as an example. They were totally unconcerned about the creation of modest quantities of formaldehyde. But they finishes they routinely used, created cyanide. Oh well.
Volatile Organic Compounds (VOC) are the smelly, often flammable, poisonous chemicals that evaporate from finishes. One expert explained that typical conversion varnishes had 6 to 7 pounds of VOC per gallon (and since a gallon weighs 8-9 pounds, that means 3/4 of your finish will be evaporating and creating a hazard). That expert went on to explain that finish chemists had reduced the amount of VOCs to 3 pounds per gallon, and the finish still worked pretty well. But when the chemists reduces the VOCs to 1 pound per gallon, the results were unsatisfactory.
The VOCs in the water base acrylic lacquer that I use, and creates a durable high quality finish (but doesn't work in the factory finishing machines) has about 1/2 pound of VOCs per gallon.
One of the "green" concerns is that forests not be depleted - that new trees be planted to replace the harvested trees. Any good businessman managing their forest would do it. But how do we know that it actually happened? There are numerous independent agencies around the world that certify that a forest is well managed, and that lumber is from a sustainable forest, such as the Forest Stewardship Council (FSC) and the Sustainable Forest Initiative (SFI). But to maintain that certification, the chain of custody, from the forest to the lumber mill to the lumber yard to the builder, has to be tracked by independent auditors, almost like the evidence in a murder case. I wonder how much formaldehyde those auditors create? And I wonder how much they add to the cost of the lumber. One of the several lumber yards I use has been certified to maintain the chain of custody.
Some of my best lumber comes from independent mills that "rescue" trees that are removed by developers and cities. That lumber isn't certified... the builder isn't going to replace the several trees removed to build a house or highway. But even though it is not from a sustainable forest, I believe it is better to use those trees for lumber than to take them to the landfill.
The need for certified products is market driven, not a national regulation. For example, in 2005 the state of Washington required that all public buildings over 5000 square feet must be green certified. The architect has to monitor the construction techniques of the building, and all the contents. So if you would like to build a desk for an office there, the architect will likely require that the desk has to be certified. A copy of the desk, scaled down if required to fit into a test chamber, must be built and sent to a testing lab which will measure any chemical emissions. Of course, the vendor must build the special item, ship it to the lab, and pay for the testing (estimated at $10,000). I bet the state of Washington will live with a lot of generic factory built desks.
One of the biggest ironies is that a building can be certified as "green" by accumulating points in various aspects of construction. If you finish the furniture on site with low emission materials, the building earns one point. But if you do all the finishing in your shop, even with the best materials, the building gets no points from the furniture. (The irony is that you may have to leave a small amount of finishing to do on-site, so the building gets credit for your good work.)
I was recently shown a web page by another woodworker, Shannon Rogers. He makes the argument that using wood is inherently "green." His article is a good read!
This site (layout and contents) is ©2008 by Charles A. Plesums, 5702 Puccoon Cove, Austin Texas 78759-7177. ALL RIGHTS RESERVED.