December 1, 2016


Show of hands, who knows what a trunnel is?

If you've read Eric Sloane's A Reverence for Wood or Once Upon a Time: The way America was, then you likely know that a trunnel (or treenail) is a hand-cut wooden peg once used by barn and bridge builders instead of nails. Some folks think this was because of the scarcity of iron nails back in the day, but according to Eric Sloane trunnels were preferred in large timber construction, because they allowed flexibility in joints as the weather and atmospheric conditions changed.

Trunnels: the origins of "a square peg in a round hole."
Drawing from page 36 of A Reverence for Wood.

But enough of the history lesson. With the goats set for winter and our summer-milled lumber curing nicely, Dan once again turned his attention to the upcoming project of building the Big Barn. One preliminary on his list was to experiment making and using trunnels.

The best way to learn a new skill is by doing. In this case, the doing was a small project - a barn bench. A bench is useful and would allow hands-on learning plus a starting point for analyzing problems and mistakes, and for honing the skill. The bench itself would be made from waste slabs cut from our pine logs in the milling of our barn posts and beams.

For trunnels he decided to use oak.

Oak trunnel and pine slab

It needs to be just the right size, not so big as to split the
 the slab, but not too small and be too loose in the hole.

Using a grinder to shave off the trunnel.

Rubber mallet for pounding in

Not bad, with only minor splitting of the pine slab.

This, however, is what needs to be avoided.
(Making the bench a good learning project.)

A useful bench nonetheless!

Lessons learned about trunnels:
  • be more exact in size (diameter)
  • taper them more

Since the slabs aren't treated, the bench needed a protective finish. I used leftover stain and finish.

Stained, finished, and ready to use.

Hay storage on the left, feed room on the right.

And there you have it.

Trunnels © December 2016 by Leigh 


Sarah said...

Well that was my something new for the day! :) Just thought it would have been a peg or a wooden nail!

Goatldi said...

Nice bench! I love the old ways and you may be familiar with the DIY show Barnwood Builders. I imagine it may be on NetFlix by now but we watch it prerecorded on our TV. I am not a big television fan but it is nice to be able to get shows like this one and enjoy learning about old barns and how they are given new life. I am sure that with all the practice Dan is getting with the trunnels that when the time comes the big barn will be "one fine barn."

Leigh said...

Well, it still is a peg or a wooden nail, LOL. I have no idea how the term went from "tree nail" to "trunnel" though. Must be the New England accent. :)

Leigh said...

Sounds like a show Dan would like, but we have't had television since they switched to digital and made everybody pay for it. I'll have to check and see if it's on YouTube!

Mama Pea said...

I'm sure at one time I must have read about trunnels in one of Eric Sloane's books, but I didn't remember it. Don't you just shake your head at the ingenuity involved with first coming up with something like a trunnel? And the idea of them being more "forgiving" than a nail during the different seasons of the year is so . . . well, practical!

Leigh said...

It's the understanding of wood and the types of wood that amazes me. Knowing what kind of tree to use for what purpose is almost a foreign concept nowadays. I hate that that knowledge is being lost.

Renee Nefe said...

looks like a fun toy for the goats too. :D It is a beautiful could probably sell quite a few of them if you had the time to make them.

aart said...

Raises hand...good book, read it on your recommendation.
Nice bench....technique prototyping is a good thing
That grinder operation pic gave me a hair raising skin that grinder securely clamped somehow?

Mrs Shoes said...

Mr Shoes loved this whole thing & swears he's going to use that idea when he builds me a new rabbit shack or a bigger chicken coop.
He did wonder though, wouldn't that bench be a little sturdier with cross bracing? Maybe it doesn't need any & it just looks long in the photo.

Ed said...

I knew what they were but I went through a faze when I once thought I wanted to build a timber framed house. I've outgrown that idea since.

I think using trunnels in your application was about the hardest way to use them so if you master it that way, you should be good to go. Putting them in a relatively thin board that close to the end of the board is probably the easiest to accidentally split the board. Most trunnels I see are set a lot further back in the beam and go through more material so aren't as susceptible to splitting things. We still have a number of old barns around built using trunnels and I have to stop and admire their beauty and longevity every time I'm in one.

Debby Riddle said...

I have the book, and we were given a mill. So excited! Dan is doing a great job, it will be fun to watch !

Chris said...

Lovely bench, and made from your own wood supplies too. It must be very satisfying. Enjoy the learning process. I look forward to seeing your new barn develop, as much as I enjoyed watching the old one get a revamp. :)

Leigh said...

It would make a fun toy for the goats! Right now I'm having trouble keeping the ducks off. For some reason they like it as a perch. I don't like it cuz they also tend to poop on it.

Leigh said...

Oh yes, Dan is very good about safety precautions. He wears safety goggles too.

Leigh said...

Actually it's very sturdy (and heavy). All three slabs are 4.5 inches at their thickest. The length is about 5 and 1/2 or 6 feet, I guess.

Leigh said...

Ed, that's good to know. Also Eric Sloane said they would often use green trunnels with aged wood. Gotta love those old barns.

Leigh said...

You were given a mill? Now that's exciting! It is so much more economical to make your own lumber if you have extra trees.

Leigh said...

Thanks Chris! He's still contemplating the type of foundation and a few other things, plus we have to adapt the floor plan somewhat since we widened the Little Barn. Hopefully we can get started on it soon.

deb harvey said...

roy underhill, university of north carolina
he used to tell about the difference wood types and grains.
he has written books but i have not read tham.

Leigh said...

Roy Underhill. Gosh that name sounds familiar. Doesn't he used to do a woodworking program for PBS? I didn't know he'd written books. I'll have to look around. Thanks Deborah!

Donna OShaughnessy said...

It cracks me up that your feed shed is so similar to ours, about the same size, hay on left, feed room on right. Except that yours is beautiful and ours may not make it another year. The before and after for sure! So love the bench built, it's part Amish, Part Mission and all Dan, you trunnel rocker you!

Leigh said...

Hey, it's a good design. :) But remember, ours was on the "may not make it another year" list several months ago. I'm so glad we made the decision to stop other projects and fix it. It will be useful for a long time to come.

Farmer Barb said...

Clever people! I have a rustic antique stool that is Swedish--early 1800's. It has native tree limbs pegged in by small trunnels for the four legs. Your hubby might like a picture of it to make one for you! It has a handle cut into the slab top to make it easy to carry.

Kiina said...

My dad used to make benches and stools from our own trees... for some reason I'm thinking that, on stuff close to the edge or that might split, he went with a tidge smaller than the hole with a slit in the peg and then used a little wedge in the slit to secure it. Like pegging the peg. But I may not be remembering correctly, it's possible that he only did that because the green wood he used dried more than he thought it would and it was loose once it dried completely. Maybe.