Managing Scraps and Sawdust?
Issue: Issue 359
Posted Date: 9/2/2014
I have a two-part question. Although this seems to be a very simple question, the answers may not be so simple. First, after making jigs, backing board, using sacrificial wood and anything else one might do: what do most home woodworking shops do with all of the leftover scrap pieces of wood? I know a woodburning stove in one’s shop will solve this problem, but what about those that don’t have a stove? Second, and probably a bigger problem, is what to do with the mountains of sawdust that accumulate? – Jerry Barnhill
Chris Marshall: Despite our tendency as woodworkers to be frugal and efficient with material waste, Jerry, sooner or later we end up with piles of little scraps that just don't have practical use. I'm not talking about valuable offcuts of exotic lumber that could become things like pen blanks or decorative splines, but rather those bits and pieces of "ordinary" scrap: small plywood chunks, slivers from rip cuts and the like. Sometime along the way, we all must decide, do I hoard it in the hope that those scraps all will find good use someday, or do we part with it? For me, scraps shorter than about a foot tend to end up forever lost at the bottom of my scrap bin. My rule of thumb is, if it's long enough to stack on a shelf and see, it's long enough to keep. The small stuff goes into the trash or bonfire pit, or I slice it up for use as stir sticks for quart cans of finish. That said, I do try to be very careful when laying out project parts to minimize the waste. With planning, I don't end up with a lot of scrap debris. I consider efficiency of material use to be part of the building process, and I don't like to waste money or resources any more than the next guy.
As to your question about sawdust waste, it's biodegradable, but that process takes a long time. If you have an effective composting routine, you can introduce small amounts of sawdust into your compost and dispose of it that way (but, be sure to read Tim's warning about this, below). Trouble is, when my dust collector fills up, I have 50 gallons of it at a time -- way more than I can compost and use practically. So, I take it to the trash collection center. I try to dump it directly from the dust collector bags so I'm not leaving any more plastic trash bags in the landfill than I have to. It's clean waste, and eventually it will become part of the earth again. I can live with that. But, I'm sure fellow eZine readers will have lots of other suggestions for you -- animal bedding, shop spill absorber, yard mulch, firestarter bricks, etc. And, the Internet has many suggestions too. Just do a search for "recycling sawdust" and you'll get a quick list of ideas in just a few clicks.
Tim Inman: I do use a wood stove in my shop for part of my heat, and I also use a woodburning boiler to supply some of the heat for my house. So, what I do with my scraps is pretty obvious. It hasn't always been this way, though. When I did not have access to a heat capturing device, I found that whatever couldn't be creatively joined into bigger blocks for turning or used some other way inevitably went into either a chipper for mulch or the dumpster. I feel much better using the scrap for heat.
As for the mountain of sawdust that builds up, there are some issues. Sawdust makes great mulch paths and garden/landscaping material. BUT! Many of the cabinet woods we use for fine furniture come complete from Mother Nature with their own built-in set of “leave me alone” chemicals in them. The resins within woods like American walnut, rosewood and even mahogany can be quite toxic to garden plants and flowers. They are nature's anti-rot, self-pesticides. The sawdust from them should not be used in places where you want something to grow. American walnut will kill a compost pile and the compost that does generate after a number of years is still toxic to things like tomatoes. So, for walking paths cabinet wood sawdust is great. For garden mulch, no. Otherwise, I'm afraid it is the dumpster for this stuff, too.
One last safety note. If you do have a wood stove, don't get it red-hot and throw in lots of sawdust. BOOM! goes the wood stove - and maybe your shop....