Monday, April 02, 2007

Playing with Sawdust

I spent a few days recently playing with sawdust and wood chips gleaned from my husband's woodworking shop. Every time he works with a wood that has an interesting deep color, I scoop up as much as I can and squirrel it away in a bag labeled with the name of the wood. Wood makes great dye! To see if a particular variety has dye potential, just put some sawdust or chips into a canning jar, add water to cover (or even better, denatured alcohol - the cheap stuff found at Home Depot in 2-gallon jerrycans). Wait a while - minutes to weeks - and see what color the liquid turns.

I have in mind a run of scarves made mostly of wood-based yarn (tencel) dyed entirely with wood-based dye, and woven in a design that evokes wood grain. I've got one threading that gives the effect of rough-sawn timber, and am working on another that'll be more like the oak face of the built-in cupboards in the house. These will be interleaved threadings, with a dark color and a light color alternating thread by thread.

First, I mordanted the warp yarns using Michele Wipplinger's method for cellulose, which consists of a scour bath, a mordant bath (aluminum acetate), and a tannin bath (I used myrobalan, a wood-derived tannin). For the skeins that I wanted dark colors on, I also put them through an iron bath at 1% WOF.

Because I planned to dye with wood, which presumably all has some tannin in it, I wasn't sure if the tannin bath was really necessary. However, because I don't know how much tannin a given wood has, it seemed as if it would be best to ensure that there was at least a known amount in there.

Here are the warp yarns. The darker skein is 100% tencel in 30/2 weight, dyed with walnut hulls harvested last fall and fermented in a bucket of water since then. The lighter skein is a 70%/30% tencel/silk blend, also 30/2, dyed with madrone bark.

While the warp skeins were in their dyepots, I mordanted the weft skeins, one for each scarf in the run. Normally when weaving scarves, I use a weft thread that's finer than the warp for maximum drape. But because there isn't a tencel thread finer than 30/2 available to the handweaver, I'm using a 60/2 silk. The mordant procedure for silk is simpler - just a scour bath and a mordant bath of potassium aluminum sulfate.

Here are the weft skeins:

From left, they are:

Logwood grey (Earthues extract)
Bloodwood (chips soaked in alcohol)
Eucalyptus (dried leaves broken into pieces, soaked in water overnight)
Koa wood (Hawaiian tree, chips soaked in alcohol)
Mulberry wood (chips soaked in alcohol) plus Quebracho Red (Earthues extract)

Don't ask what kind of Eucalyptus it was. I harvested the leaves a couple of years ago when a neighbor gave his hedge a crewcut. They've been drying in a box in the garage since then. Here's a picture of a couple of the dried leaves. They range from 1.5 to 4 inches in length and are a silvery blue/green. There are probably more different varieties of Eucalyptus than any other type of tree. This one is a mystery. All I can say is, the leaves dye yellow.

The skein on the right in the photo above started out as plain mulberry dye, but as you can see from this picture taken while it was in the dyepot, it was fairly close to the eucalyptus in hue, and I wanted more variation in the weft colors.

So I looked in my dye cupboard for another wood-based dye that would shift the color a bit. I had some small amounts of the various Quebracho extracts from a warp-painting class with Michele, so I added a gram or so of Quebracho Red to the bath, and got an apricot color I liked better than the yellow.

The Koa skein, second from right in the picture of weft skeins, really surprised me. The chips were dark red, as was the liquid they soaked in, so I expected a reddish color on the skein, not the deep bronzy gold I got. And there's a ton of color in just a small volume of chips! I had filled a quart jar about 2/3 full of chips and covered with alcohol. The jar sat in the garage for about a week. When I went to use it, I just poured the contents of the jar into a dyepot, added a quart or so of water, simmered the whole mess for a few minutes, strained it out into a clean dyepot, and added the yarn. The color took almost immediately, to very deep value, but to make sure it would really be color-fast, I left the dyepot at under 140F for several hours.

Carol Lee of the Sheep Shed Studio in Wyoming has done a lot of wood chip dyeing, and teaches a class on the subject. On Carol's advice, I kept all the dyebaths at a low temperature (around 140F) to prevent the colors from turning brown with excess heat. All, that is, except the walnut, which I boiled to kill off the various forms of life in the bucket and reduce the smell somewhat. I also strained it twice to get the sludge out of it. Walnut is a dye you don't want to do in the house. It's really stinky, especially when it's been fermenting for months!

I had hoped for a deeper brown from the walnut, as I've gotten in the past on protein fibers, but the tencel just wouldn't get any darker, even after 24 hours in the dyepot. I was glad I had done the iron bath, or it would have been an awfully light brown!

Both of the warp dyebaths were cooked on a propane camp stove out of doors. The weft skeins I cooked in the kitchen, although DH complained that the alcohol made the house smell like a hospital. Fortunately, the weather was pleasant so I could open windows to air the place out. I am really looking forward to having a proper dye kitchen, so I don't have to cope with a propane stove outside in a breeze, or worry about getting my indoor kitchen spattered with dye or smelly with witches' brew concoctions!

All in all, it was a very successful dye project. Now, if only I could get the weaving design to do what I want... In the meantime, another warp goes on the loom and I'll keep working on the wood design in my head while weaving something completely different.


Kate said...

Those colors are gorgeous, I hope you show the finished product.

Willington Weaver said...

Wow, Sandra, what fantastic colours, please let us see the finished scarves.

beryl said...

I really like your process photos. A word on Eucalyptus - the Silver Dollar type that florists use give a rust color that is beautiful. I'm not speaking from personal experience, because I left the land of the Eucalyptus without having tried them, but I've seen samples that were gorgeous.