In the early 1980s, a woman that owned a doll shop in Pontiac, Illinois, contracted me to make several items for her shop. One of these was a baby's cradle with a bent roof on one end. At the time, I tried soaking the pine for days in a garbage can full of water.......and it would not bend. I finally made many saw kerfs with the radial arm saw and successfully bent it. I always wondered how I could have steam bent it.
In 2010, I bought a book about steam bending:
In August of 2012, Rockler sent me an email with a bargain price of $74.36........
So, I bought the kit from Rockler. You have to make your own steam box, and the kit includes a hinge for the door.
I built my steam box from scrap plywood.......
Next I needed to design something that required a bent wood piece. I googled for clock patterns using bent wood parts and was surprised not to find very many patterns. I came up with my own design using Google Sketchup:
When I did this design, I was not aware of steam bending capabilities, in terms of what the minimum bend radius is for 1/4x1" maple. I arbitrarily selected a 1 inch bench radius, because it fit the over-all clock scale and movement I wanted to use. After playing with steam bending, I think a 1" bend radius is difficult to achieve.
I also designed a drying frame:
The steam bent pieces have a 1 inch bend radius, and are 1/4" by 1".
Somewhere I read that white oak less than 1/4" thickness can be steam bent without using a compression strap.
I was unsuccessful in bending the white oak with my set-up. I failed at least 9 times.
I increased the bend radius from 1.0 to 1.5 inches, but I still broke the pieces.
I decided to build a compression clamp to restrict the outside of the bend from fracturing.
The only strap I had immediately available was galvanized plumber's strap. I was again unsuccessful bending 1/4" white oak 1 inch wide. Since all the failures were the outside of the bend, it meant I was not restraining the OD of the bend enough. I studied my fixture, and concluded the stop for the unbent end of the piece was deforming too much:
I replaced the 2 drywall screws with 2 machine bolts. This time I was able to bend 1/4" by 3/4" piece of white oak with a 1.5 inch bend radius !!!!!!!!!!!!
Below is a picture of the first 2 successful steam bends I did on 1/4x3/4 white oak with a 1.5 inch bend radius......
The top piece with the biggest spring-back, is the first successful bend I made......with a 1.5 inch bend radius and 1/4x3/4 inch white pine.
I was surprised in how much spring-back there was, after I removed the piece from the bending form. I traced the actual bend on paper, scanned it, and compared to the theoretical shape in Google Sketchup...
I think the handbook said to expect 15 to 25% spring-back. So I modified the bending jig to try to compensate for the springback...........
As the lower piece in the picture above illustrates, I probably over-compensated when I cut this angle in the jig. I guess this illustrates there is a lot of trial and error associated with steam bending!!
April 2016 Update
I did not have very good luck the first time I tried steam bending, so I put steam bending on the back-burner and moved onto different projects. I pay attention to any articles I run across about steam bending trying to learn more about it.
In March of 2007, Wood magazine ran an article about steam bending. In the article it says that kiln dried wood is very hard to steam bend. Ideally, you steam bend wet oak, or air-dried oak. The steam bending expert says if he has to steam bend kiln dried oak, he soaks it for 1 week minimum in water and fabric softener. He also says it is best to secure the ends of the steam bent piece, so they don't change over time.
I will have to try the method of soaking for a week in water and fabric softener.
November 2016 Update
I did another Google search looking for clocks made from steam bent wood. This time I found one on this website.
Here is the text that goes with the photo above...........
Steam bending has always intrigued me. I had designed this clock on my computer first. After making the steam box, and several tries at steaming, I achieved the desired results. The arches are laminated. The clock is solid oak, even the hour and minute hands.
This design does follow the guideline of anchoring the ends of the steam bent pieces, so they can change over time.