Editor’s note: Our Mind Upon Mind series is a nod to a 1937 Chips from the Chisel column (also featured in “Honest Labour: The Charles H. Hayward Years”), in which Hayward wrote, “The influence of mind upon mind is extraordinary.” The idea being there’s often room for improvement. To that end, we’ve asked you what else you have thought of, tried out and improved upon after building projects from our books.
Send us your own ideas! Email [email protected]. You can read more about the submission process here.
Today’s pick is courtesy of Rob, from Peachtree City, Georgia. Thanks, Rob!
— Kara Gebhart Uhl
This steambending tip is for kiln-dried hardwood.
I am building two staked side chairs from “The Anarchist’s Design Book” to go with our dining room table. Both are built out of kiln-dried cherry and I’m using the simple steambending jig as shown in the book.
The crests are 13/16″ thick and need to be steambent to a 15″ radius.
I have built four of these same chairs previously, two out of ash and two out of cherry. The ash crests all came out well, but I had several failures while bending the cherry crests. Even when using straight-grained wood, cherry is prone to cracking and is a more difficult species to bend than ash or oak. This time around, I had three failures out of my first four attempts. All the failures were on the outside of the curve.
I knew a jig with a compression strap would give better results, but didn’t want to spend the time and energy to build a more complicated, albeit better, jig.
I had seen articles or videos in the past about steaming wood inside a plastic sleeve. While thinking about the best way to do this, I remembered that we have a vacuum sealer machine in our kitchen.
The crest is 18″ long and 2-1/2″ wide before steaming, so an easy size to work with the vacuum sealer. Vacuum sealing makes the bag/wood combination smaller and easier to handle and clamp, but still leaves plenty of moisture.
Here’s my process:
1. Soak the cherry for several days.
2. Put the wet wood in the bag and vacuum seal.
3. Steam for one hour.
4. Put the wood and sleeve in the bending jig together and clamp expeditiously.
5. After the crest has completely cooled and is at room temperature (4 to 6 hours), I unclamp the crest, remove the sleeve and reclamp in the same jig. This helps start the drying process, but it won’t dry very much while in the jig.
6. The next day, I remove the crest and put it in a bar clamp to dry. The wood will still be very wet and there will be some spring back. Tighten the bar clamp to match the 15″ radius of the bending form.
The sleeve retains the moisture during the steaming process, which is more efficient in conducting heat. Steaming without the sleeve heats the wood but also removes much of the moisture. The bag also helps retain heat and slows the cooling process while transferring and clamping in the jig.
If you plan on doing much steambending, my advice is to build a jig with a compression strap. In lieu of a compression strap, I think this is a good workaround.
So far, this technique has worked well after a handful of attempts.
— Rob
Nice tip. I’m actually going through some of the same stuff with the same chairs right now and have had trouble with the cherry too. I punted and I switched to red oak and have changed my bending form.
Here is a thought I had about this style bending form but have not tried yet. What if you built the top of the form wider and installed blocks to contain the blank before closing the form. When you crank the two halves together the blocks would add compression much like a strap. Haven’t tried this, it’s just a thought.
I haven’t tried that approach, but I’m not sure it would help. All my failures were on the outside of the curve, which is unsupported during the bending until the form is fully closed.
I think this sleeve technique helps because the wood stays wet and stays hot longer.
Even with this method, you have to be quick. My first try with this failed because I took too long to get it all clamped up. I was quicker the next three bends with good results.
Kiln dried cherry is finicky to bend.
I was wondering if a “standard” vacuum bag would also work for those of us without a vacuum sealer?
I think almost any plastic sleeve would work as long as it wasn’t too thin. I was looking online to order something before I thought of using out vacuum sealer and bag.
The vacuum sealing just takes out the excess air. It doesn’t contribute to the process other than just making the wood in the bag a little more compact.
Lots of people use shrink wrap tubing. Packaging suppliers like ULine sell it and it looks it can be found on Amazon too.
I was looking online to buy some when I realized we had the roll of plastic for the vacuum sealer. I don’t steam bend a lot, so it was nice to use something we already had.
In the late Ken Parker’s free YouTube video series “Archtoppery,” Ken made an etude (a longer video series) on bending sides (for guitars). Ken was an early contributor to “Fine Woodworking” magazine and a legendary guitar maker (innovator of the Parker Fly guitar). He uses bias cut handkerchief linen (a lightweight linen and cuts it into a square at 45 degrees to the weft and warp of the fabric). He lightly epoxies it in the side that will be in tension and lets it dry. He demonstrates this technique with curly Italian chestnut. After he bends he uses a clothes iron to remove the epoxied cloth. He says you can bend anything this way. Ken was an amazing guy – he had patents using fabric in guitar technology and was a toolmaker and expert craftsman. (he passed away in late Dec last year). He had a grant and very talented help to make the large volume of shop videos. And they are about mich more than Guitarmaking. Anyone doing work with bent or carved wood or who works with power or hand tools will benefit from watching this amazing guy share his deep knowledge of craftsmanship.