Week 2-5: Fabrication progression
In the past few weeks, I have tried to push myself to get my steam bending finished as soon as possible. By end of this week, I have finally finished all my steam bending tasks, in total of 8 pieces were bent, and all are now left to dry for 2-3 weeks.
My thesis chair’s head rest and bottom rail both are made of steam bent parts. As I mentioned in my previous blog post, I have gathered some air dried material for my steam bending during the New Year break. Additionally, according to my digital drawing, I needed to fabricate a brand new steam box to fit 9 feet long stocks. I used water proofed plywood create multiple double layer steam boxes, and they are interconnectable and interchangeable to fit different length (The kit is also made for the studio). In the images on the left, you can see the boxes construction and steam in progress.
The second challenge was to figure out how to bend a piece at 9 feet in length. It was almost impossible to create leverage and bend it from a single end, because it will take too much space to swing a full circle in 20 feet radius. I received consultation from faculty member who was saying that I should bolt the form on the floor and bend it by using come-a-long puller. This idea significantly reduced the space and physicality of the steam bending. I was able to bolted a metal bar that has many brackets attached to on the floor, which used for changing the direction of the pull on bending tool. Moreover, I extended the bending tool with additional metal bar and attached one shackle at each end for the puller to hook onto.
Next, I created the digital files and cut bending forms and drying forms on the CNC router. As you can see in the images on the right, I laminated one layer of plywood in the middle of the bending form to increase strength of the lamination. Then I added spacers under the form and elevate the form to create the alignment between the center of the form and the hook point, which is to ensure the pulling force is in the center of the stock while steam bending.
More importantly, the key for steam bending is to control the heat. It is difficult to maintain the temperature on 2’’ X 2’’ X 9’ stock once it is being taken out of the steam box. To slow the process of losing heat and extend the time window for steam bending, I put the stock into a plastic bag, and hook the steam into the bag to keep temperature up. This technique has made the process more relax. In the video I linked below, you can see the entire 25 minutes process of bending in time lapse. Finally, I managed to finish all 8 pieces in a week; I transferred them to drying forms and secured them with metal straps.