I was wrong about that

The last post was about hickory bark, peeling it, and the ease of weaving. I know more now, though I’m not exactly sure what I know. We wove 15 seat bottoms at Woodcraft within Berea College over the past couple of weeks. Plenty of time to try different approaches and techniques. The first few were woven with the thick, dark bark just as we received it. Just put it in the seat. It required too much wrestling to get into place and yields a dark brown bottom, but it stayed in place, looks good and is plenty durable.

We started peeling the thick bark into an outer and inner bark. It gave a more consistent light brown look. It was MUCH easier to weave and splice. We ended up with shorts, run-outs and poor areas in the bark that cannot be used – but this was a minor issue.

The more significant issue is that larger gaps appear as the thinner bark dries. It significantly shinks across it’s width. I do not believe that I kept it in the hot water for too long. I placed the bundles in hot water for 30 minutes or so before weaving. It was still partially stiff, yet plenty flexible to weave, pull taught, and press the rows (and weaves) closely together. Even so, larger gaps appear as the seat dries. This is a fairly typical apprearance with hickory bottoms and it looks good on the stools (and chair – more on that in the next post). The image above shows some of the varience within the stool bottoms.

The thicker bark didn’t seem shrink as drastically as the thin stuff. Why? Maybe it’s something I did during prep. Maybe it’s the species of hickory we’re using. It’s possible that the bark was harvested during an extremely wet period of this past spring.

My current working theory is that the inner bark, closest to the cambium layer, shrinks at the highest rate. The thicker bark, and the outer bark, doesn’t move as much as it dries. So thicker bark keeps closer to the wet, woven shape, while the thinner material shrinks mightily. Of course this is just a thought. But it’s the best one I’ve got right now.

more on bark

This has been a process of learning. And I hope it stays that way. We’ve been weaving hickory bottoms into stools at Berea College Woodcraft. The semester is winding down and we’re trying to finish up a run of stools. Nine of the fifteen in the run are now bottomed. The bark we got from Steve Farmer is good and thick and looks great in the seat, only it’s a real wrestling match to get it into place. It’s just so thick.

So we’ve found we have a couple of options with it:

  • leave it thick and weave it tight. It’s just too tough to do it this way, though the finished result looks good. But we’re finding the last half of the weave to be so tight and tough that it’s nearly impossible to thread the thick bark through the tight warp.
  • another option is to leave larger gaps between the warp and weft. It makes for easier weaving but the gaps are too large, especially as the bark shrinks as it dries. Not the best option for us.
  • use the thick bark and leave the warp baggy or loose, though the rows are tight together – then weave the weft as tight as possible. We’re having good luck with this approach.
  • Today we tried peeling the thick bark into two lengths. First time I’ve ever tried it – it’s kind of like riving wood, only using the pressure and support of your hands to control the split. I found that the outer bark needed to be a little thicker than the inner during the split (and not 50/50, though it’s a challenge to control the split that well). At times the inner bark would pull a swirl of grain or furrow with it, leaving a hole in the out bark split. Keeping the outer bark run a little thicker than the inner seemed to remedy this issue.

The thicker bark is finishing up nicely. We occasionally find a small tear around the seat bend on the thick stuff and shave that tear away – though that hasn’t happened much. Thinning/splitting works well, except around any knots or funky areas. Then it runs out and makes a mess of things. It seems like the inner bark has yielded the better run, and any run out or thinning issues happen to the outer bark. There’s no harm in it, since the thinner is much easier to weave and, at worst, we need to splice a few more areas together due to a few run outs.

finishing the hickory seat

completed hickory seat

Last post on bark for now. I went about finishing the seat for use after putting in the seat and letting it dry for a couple of days. During the time after weaving in the seat, during the days that it’s drying, I adjusted the spacing of the weave once or twice. The drying bark will shrink, leaving negative space, and I tried to adjust the spacing while it’s still slightly pliable – it gets a little tougher to adjust after completely drying.

scrubbed bark – frayed edges
after removing frayed edges, before oiling

How I went about finishing this seat:

*completed the weave, adjust bark accordingly

*scrubbed the bark with a stiff bristle brush, to raise all the frayed edges and strands

*removed the frayed strands

*sanded the bark in places to smooth minor issues and edges

*coated with thinned linseed oil

oiled seat

This stool design isn’t overly refined. It has tool marks and other indicators that it was made by hand. I laid out the detailing on the rungs by eye, so each one is a slightly different than the next, just by my human imperfection. I think the small differences make the stool look right. The preciseness gained by machines or rigid uniformity in layout would sterilize the stool, making it look mass produced and kill any charm it might obtain. With that in mind, a few gaps or less than perfect hickory bark does not bother me when bottoming the stool. While my intention is not a truely rustic piece of furniture, the bottom (imperfections and all) emphasize that a person made the stool.*

*Side note: The hickory bark can be dressed up much more than I’ve described, and the approach – while being similar to what I just described – would include more steps to improve the quality and consistency of both the bark and the weave. The seats added by contemporary chairmakes can be tight, uniform, and blemish free. My stool is not those things. Then again, it wasn’t my target.

hickory bark resources

Here’s where I turn for hickory bark knowledge. I’m sure I’m missing good sources and reliable info, this is just a simple list of where I start.

And two sources for purchasing bark:

more about hickory bark

I recently visited Covington, KY for a Lie Nielsen handtool event held at Lost Art Press. For some unexplainable reason, I figured it’d be fun to demonstrate seat weaving on a small stool for a group of tool event attendees. Not that weaving is upleasant or unworthy of demonstrating, it’s simply that it can take a while to get a good weave (at least for me) – especially if the bark has knots or other issues that need addressed. I wasn’t as confident in completely weaving a seat in a short period of time with an audience. The last seat took two hours to weave (the weave from the previous post). I was fearful that boredom might set in at that rate.

The freshly woven bottom from the tool event.

A quick breakdown of how I went at the bottoming at the event:

  • tacked the starting edge of the bark roll twice against the side rail
  • began wrapping the warp (front to back) around the front and back rails – with the smooth, tree side of the bark to the inside
  • notched and joined pieces on the underside when the bark had knots or voids
  • pulled the warp tight at every opportunity to keep weave tight
  • at the end of the warp, on the underside, tuck bark around leg and begin the weft (see image)
  • herringbone pattern – a simple, repeating pattern after four rows. Essentially under two, then over two, with the leading edge changing each time
  • same pattern on the underside
  • kept each weft row tight to the previous row – to keep the gaps to a minimum upon drying
  • finished by weaving the lead edge into the seat on the underside – no tying required

Forty-five minutes. That’s what it took. And no blood – that’s atypical for me but nice when working in front of a crowd.

thick hickory bark

Working in Berea, KY means there is a strong tradition of hickory seats all around me. Just up on the college square, a short walk from where I work, there a few small business. Two of them (maybe more, I haven’t scouted them all) have older mule-ear chairs behind the register for the shopkeeper to rest on. I’ve enjoyed examining these chairs. Each has an issue or two – like a broken seat rung, or an unevenness of the back posts – that demonstrate the use it’s seen over it’s life.

The hickory seat in each chair is beautiful, even with the age and broken pieces that are apparent upon a quick glance. Even with broken pieces throughout the seat it is still plenty strong enough to hold my weight. I won’t even venture to guess when the chairs were bottomed – they’re at least a few decades old. The bark has taken on a smooth, shiny, worn-yet-consistent look, along with a deep color that must have come with age. I’d guess the chair bottoms were oiled a few times over their lifespan, but that’s really just a guess. The bark is around a 1/16″ thick throughout the weave.

Thick bark beside thinner (preferable) bark

I recently wove a small stool with thicker bark. Bark that approached 1/4″ thick (while soaking wet) at some points. And in doing so, I came to realize why thinner bark is preferrable. First off, the thick bark wouldn’t soften for the weaving. Even using scalding hot water, with a small amount of soap added to bath, it was still too stiff to weave after a few hours. I let it sit in the water for 24 hours. It became stiffly pliable the next day, enough so that the seat could be woven. But it was a fight.

I’m not a hickory expert, so a more experienced weaver may laugh at these thoughts. The warp wasn’t too difficult, since it was primarily just wrapping the frame front to back. It was the weft where I knew I was in trouble. The tight warp, along with the thick bark, made weaving in-and-out of the seat challenging. On previous seats, with thinner bark, it was easy to manipulate the leading edge in-and-out of the warp. Not so with the thick stuff until I thinned out the lead edge to knife point.

Bark after weaving. The warp is mostly tight across the front rail.

Then came the challenge of getting a tight weave. That was impossible, as the heavy bark prevented the weft weave from coming anywhere close to the previous line. It took a good deal more effort to weave this seat in relation to the previous work I’ve done with thinner barked . It was a struggle to pull the line of bark through the seat even after I got the lead edge through the warp.

After weaving a row, I would push that row as tight as I could to the row before it. There are wide spaces between the rows of weft – probably 1/4″+ or so. It looks good on this seat, since it’s a single piece and doesn’t need to match other work. The wider gaps gives it a rustic look that is completely appropriate for the ash, post-and-rung stool.

Before trimming and oiling. Note how the gaps opened on the front rail after drying – due to the extensive soaking

It’s clear now why chairmakers dress the bark before a bottoming, thinning the thick areas and trimming the edges to get a more consistent width. It would be impossible to make an even, tight and consistent bottom with thick bark. And a rustic weave might not look right on a comtemporary or clean-lined chair.