The next challenge was the round window overlooking the lake. I was not happy with the idea of simply cutting a round hole and facing it with a flat ring sawn out of similar material. This in my mind did not look authentic and in any case I needed to fill the full 4" thickness of my walls. What I wanted was a bentwood ring around 750mm in diameter, 4" wide and at least 1" thick. I quickly determined that there was nothing suitable available and commissioning a custom fabrication would be prohibitively expensive (if possible at all). So if I was going to achieve what I wanted then I would have to make it myself.
There are two main ways of bending wood - steaming or glueing thin strips together in the required shape (a glued lamination or 'gluelam'). There is also kerf-cutting, which involves making a lot of cuts in one side of a piece of wood to allow it to bend to the required radius, but this needs to be done on the inside of a bend and hence would not be suitable in my case.
.jpg "click to enlarge")
I decided first to try the gluelam approach. I found a very useful article here and built a semi-circular form as shown right. Since I did not have access to a table saw to cut my own, I then started searching for suitable stripwood. Unfortunately, all I could find in the required width was 6mm pine (I could have used veneer, but the thickest I could find was about 0.6mm, which would have required far too many layers to achieve the required overall thickness). It quickly became apparent that this would not bend to the required radius even when soaked, so I would have to use steaming before lamination (it is possible that thin hardwood would bend more easily than pine, but I could not source this in a suitable width and thickness).
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