Uses for wood chips

A by product of my 'day-job', furniture making, that supports my art work and studio, is large amounts of wood chips and saw dust. These 'chips' are actually quite small flakes that are the by product of planing hard woods. I've been trying various methods of using this material as filler in resin castings with the hope of making usable parts such as small table tops, chair seats, etc. I'd like to develop a materials and methods that other woodworkers could use instead of sending this 'waste' to land fills.

I've used wood shavings + chips in sculptures, mixed with glues and shaped into forms. Although this is exciting it doesn't have the promise of using even a small percentage of the wood chips I generate, even though I'm a 1 person shop. I'm looking for ways to incorporate this material into structural parts. Does anybody have any ideas?

Todd Fillingham http://www.fillingham.com

The wood chips I have as 'waste' are from kiln dried hardwoods. Moisture content is pretty low, probably around 10% or less. The moisture taken-up while the chips are stored would be hard to measure w/o doing the weight/ oven-dry weight test. Is the moisture content a problem because of a reaction to the resin? Does this create structural weaknesses, bubbles? What type of resin have you used? So far I've tried only epoxy resin, which has not been successful, primarily I assume, because of the exothermic nature of the reaction. I tend to get rather significant bubbles in the casting. I've tried setting the test casting in a cooling bath of water, with some improvement, but this would not be practical for general use. I know that Gaetano Pesce has done a lot of work with casting epoxy resins, I'm just not aware of which epoxies he uses.

The 'waste stream' from my shop is mixed hardwoods, primarily birch, walnut and cherry.

I'm located in Milwaukee, WI, US. Where are you?
http://www.fillingham.com

I can't offer any ideas for sculptural uses of these wood chips, but I know of another use. Many cat owners and breeders use wood chips mixed with sawdust as litter. It is healthier for the animal than clay litter, and can be recycled as compost or mulch (minus the solid waste, of course) after use. The CFA website would have lists of breeders in your area.

Mary

Thanks for the suggestion. Currently I do provide bedding etc. for my neighbor's menagerie of cats, rabbits, hedge hog, etc. And I am turning a large bag of wood chips into my home compost on a regular basis. I am also going to try using the wood chips as bedding for indoor vermiculture composting with a small sideline of offering compost from my studio. (Perhaps plants too, I'm hoping to find time to develop 'turnkey' set-ups for indoor air purification by using plants.) Not to mention using the chips as mulch on our small, urban garden. My hope, though, is to develop techniques that can be used by other artists, woodworkers, furniture makers to shift their 'waste' into a resource for the production of valuable objects. Maybe then I can have some impact beyond my own responsibility for my waste.

Ooh, well that reminds me that those fancy shmancy (and expensive) dog beds that you can buy are usually stuffed with wood chips...do you sew ?

A very interesting idea. I think it's more likely that you're just trapping a bunch of air in your epoxy/wood chip matrix. A 'professional' casting expert would 'degas' the pour in a vacuum chamber first (which would drive all bubbles out) then follow that up w/ pressure during curing (that would ensure good penetration into the wood fibers, and all the smaller nooks & crannies that the high viscosity of the resin would otherwise be prevented from entering.

This equipment is of course expensive, especially on a large scale (I'm considering getting a smallish pressure/vacuum chamber for resin casting purposes.)

I know a guy named Nick Hill, who works w/ these techniques. He's a chemist and has developed his own silicone molding compounds and water-based urethane casting resins. He mostly works in the high-end art-doll field.

Cheers, Dan Schumacher

An interesting idea. I'm not all that interested in getting too fancy schmancy for dogs. Fancy schmancy art is something else . The idea of using sawdust & woodchips as stuffing is not new, however I've completely overlooked it. I use to sew sails and have in the past collected sewing machines. (I think I gave my last good one away to a former studio assistant though...rats.) Large, stuffed, sewn sculptures are intriguing though. Thanks

You suggest the bubbles may be due to the entrapment of air in the matrix. That does sound reasonable. It is interesting, though, how it manifests; the resulting casting resembles Swiss cheese, i.e., the bubbles are quite large, up to 0.25' in diameter. I have used many fillers with epoxy resins, primarily West System and have not had this problem, albeit the fillers are much smaller particles. Perhaps I'll try stirring or vibrating the mix during initial set to see if I can get the entrapped air to rise to the surface. I also agree w/ your drift that I should be looking at other resins. Would your friend Nick Hill be willing to entertain a few questions via email? BTW: What sort of objects are you planning to cast?

Hi everyone.

While I was surfing I came across a new site from an artist (Jim Conrad) who does bronze sculptures depicting action scenes from sports. He has done pieces on baseball, football, basketball, sumo wrestling, and more. He also had some pieces of animals from nature scenes. He does really good work and his site is laid out pretty good. If you get a chance stop by and check it out. It is at http://www.mindseyeweb.com/jcon/. Leave me a reply about your comments if you do stop by.

Sorry, I've been away on holiday break.

I do recall that vibration is another 'poor man's' method of degassing also (though less effective.) It'd be worth a try.

Your original idea that the bubbles were water vapor caused by the exothermic reaction sounds very possible.

I don't think Nick would object, but I don't have his email address. I'll

She's just having her first bronze cast in a couple weeks. See her work at: www.hclodge.com/dolls.html. She'll give you Nick's email address (if she thinks it's OK.)

We'll likely be making silicone rubber molds of her sculptures, evenutally. We haven't really geared up for it yet.

Cheers,

Another application is to use to wood chips & dust as a filler in casting media such as urethane resins. Fillers can be used to make resins take on a cellular structure to simulate wood. Fillers also get used as extenders in urethane resins depending on the amount added into the resin mixture. Generally the more filler added the thicker the mixture, which can even be good if you're doing a vertical application - the mixture can be trowelled onto the surface. You just have to be careful because dust & chips can contain trace amounts of moisture which can cause urethane resins to foam, which is usually not desired. I recommend baking the filler first at a low temp to evaporate the moisture then it can be added into the resin system.