Steam Bending Cherry

[James Tibbetts]

My next project is a small table and chairs made from cherry. I would like to bend the back chair legs.
How well does cherry respond to being stem bent? Will it affect the color later on?
My first time down this road so any information will be greatly appreciated.

Thanks.

[Mark Bolton]

You bend green wood.

[Bradley Gray]

I bend 3/4 x 1" cherry regularly for the music stands that I make. Air dried is better than kiln dried. I steam the wood for 1 1/2 hours after it reaches 210 degrees. You will need to make a steel strap with end blocks - I found a roll of 1" wide sheet metal used to hold fiber insulation in place at a surplus place and I use wood end blocks. With strap 10% fail rate - 40% without.

The Earlex steam generator is good, but it only produces for about an hour. I use 2, but if you pay attention to it and refill as soon as it stops producing 1 steam generator will work but take longer.

The grain gets raised, but steamed and non- steamed parts finish about the same.

[James Tibbetts]

Thanks guys.

[Lee Schierer]

I have steam bent kiln dried cherry. You need to steam it for a good long time and have your forms set up so you can bend it into place quickly and clamp it securely while it is still very hot. Having a backer strap will lessen the chance of the piece braking. Bending a 3/4" thick piece is going to take considerable effort if you can do it at all, depending upon the length of the piece and degree of bending. It was all I could do to bend a piece that was 5/8" x 1-1/2" 40 " long into a shallow curve for the top of a baby crib. Leave it in the form for a week or more and expect it to spring back toward straight.

[Walter Plummer]

Check out this video. https://www.youtube.com/watch?v=mHAbShWQ7JI&t=2s

[Prashun Patel]

What is your chair design? The severity of the bend and thickness of the piece will dictate your steam time and how forgiving kiln vs air dried stock will react.

It’s easiest with green stock if you can get it.

Beware your grain run out.

[David Utterback]

Fine Woodworking article on bending wood just arrived in the mail yesterday. I have not read it but they show a variety of methods. Good luck.

[Tony Shea]

I recently bent some 3/4" thick kiln dried cherry for the first time ever steam bending. The bend was NOT successful but I did learn some things in the process. Find completely defect free, straight grain wood!!! This is super critical. You absolutely need a backer strap that has blocks to keep the piece tight between the blocks. This backer strap needs to cover the full width of the piece. You also need to let the piece soak for a solid 1.5 hours at 210degF minimum.

My failure was due to not letting the piece soak long enough in the steam as well as the strap width did not cover the entire width of the piece being bent. The cherry started cracking at a point outside the strap on the outside of the bend. This crack never entered into the area of where the strap was covering. My other issue was the piece cooled off too much before I was able to bend all the way therefore tried forcing it. You need plenty of leverage and the form needs to be extremely solid to the bench. My form was just loose on top of the bench and I did not have a long enough handle on the end of the strap. I basically ran out of time and had to force the wood which ultimately caused it to crack.

This one failure taught me a lot and I do believe it is possible to get this bend done. I just need to re-do the strap, let the piece soak in the steam longer, and prepare the form/handle for much more leverage. I've considered wrapping the piece in plastic wrap as soon as I pull it out of the steam so it holds the moisture/heat longer during the bend. This bend is possible in Kiln dried cherry but you def need to be prepared for failures and over estimate everything.

[Jon Grider]

Check out this video. https://www.youtube.com/watch?v=mHAbShWQ7JI&t=2s
Now that is some serious steam bending. Amazing video. 9/4 oak with no splitting, this guy is wealth of knowledge.

[James Tibbetts]

I have watched some of Engles' vids before. Very impressive and tons of great information.
I will try to post a sketch of the bend I'm considering and material thickness and you guys can make a more accurate assessment of how much trouble I'm asking for.
Thanks to all for your information and experience. I value the latter the most.

[Tom Bender]

Hi James
If you are making side chairs you may not be asking for much of a bend. It should work out ok and you may not need a backing strap. I had success bending 1 1/8" thick x 9" wide KD Ash without a strap into bowfront drawer fronts. That took a lot of force! Wife had to help out. Overnight in the form was plenty. You will need to make a couple of practice bends to work out forms, force, speed and springback. Also, a steam box with steam coming out the opposite end is not necessarily up to temp. Use a thermometer nearer the bottom and start timing when it goes over 200. Good luck.
Tom

[James Tibbetts]

Thanks Tom and all others. The design will not require much of a bend and it will likely be in a single plane, that way 1 form fits all.
Time to build a box and experiment.

[Mark Gibney]

When I steam with the Earlex I boil a kettle and refill the steamer when the reservoir runs low.

Anytime I’ve steamed KD wood it has never worked out. Might experiment again as some of you have done this with success.

[James Tibbetts]

I think I found a source for quarter sawn air dried material. That should bend well and the pieces will be small enough to finish dry in my light bulb kiln.
Trying some KD is still in the plans just for education.
Exactly what I was thinking for the refill Mark.

[Mike King]

If all you have in kiln-dried, then try soaking the part overnight before steaming. Believe it or not, it really makes a difference in the result!

Mike

[James Tibbetts]

I had wondered about doing this. The wetter wood should transfer heat to the center much quicker.
Thanks for the confirmation !

[Tim Janssen]

I make my steam box out of foam sheet. Easy to make different shapes depending on what I'm bending.

417529

417531

And use long deck screws to hold it together. Works very well
Good luck with your project,

Tim

Sorry that last picture should not be there. I can't seem to get rid of it

[James Tibbetts]

Nice set up Tim.
No sealant of any kind on the joints? I wonder if silicone would work on the foil faced stuff.

[Tim Janssen]

Nice set up Tim.
No sealant of any kind on the joints? I wonder if silicone would work on the foil faced stuff.

Thanks James,
No, I didn't use any sealant, just the screws. No harm trying though. My only concern would be if the heat might effect the holding power of the sealant.
By the way, the lids were not screwed on. I just put some weight on them to keep them in place.

Tim

[Tom Bender]

James
Bending in two directions is more challenging but it can really improve the end product. Two approaches;

Make a form that accomplishes it in one steaming. Not so hard when you think it thru. Steaming twice into different froms will fail as the first bend will mostly uncoil in the second steaming.

Steam in one plane and saw in the other, which to do first is best determined by practice.

[James Tibbetts]

I have a picture in my head of the form to bend both directions, which I agree takes the final product up a notch or two.
The two way bend requires a second form that mirror images the first. Shouldn't be a big deal once the first one is correct.
I'm very much looking forward to this as a challenge and a learning experience.

[Tom Bender]

It may be better to make a concave form. You could start with a big hunk of wood, maybe a 4 x 6. Bandsaw the first curve. Curf some thick plywood so it will bend and tack it to the 4 x 6. Draw the second curve. Untack it and cut, retack. Add layers as needed. Glue all that together. Don't want it to slip. Make some places on the back for your clamps to land. Now make some small cauls for the clamps, these should have notches and angled backs for applying force at an angle. Label them. There will be a lot of cauls and clamps so you may want an extra pair of hands for the big minute.

This could all be the same if you did a bent lamination except you'd add package tape to prevent gluing things together.