JMB,
Looks awesome!
As for the steam bending, I've never personally done any, but I've seen it done up-close and assisted with clamping the pieces. I can see a few issues straight off:
1. The profile you're trying to bend is wedge-shaped, so it will have a natural tendency to bend in a different plane to what you want;
I thought the same thing but then thought cus we steamed it we can still bend it how we wanted (oh how wrong was I lol)
2. Your steam box isn't insulated. With a long box like that, by the time the steam gets from one end to the other, it won't be steam anymore, just hot water;
Oh it was Dam hot in der I stuck my arm in it and 1 second and I had to pull it out as it kinda hurt.
3. No timber should need to be steamed for 9 hours! The main idea of the steam is to get the timber hot, not wet;
I thought if we do it for that long it would be guaranteed it would bend easily I was wrong again!
4. As Matt mentioned, you need firm support for the timber. Ideally a male former, and a flexible steel strap with end stops.
For something like this application, laminating would have been a better idea, and wouldn't have been quite as big a headache as steam bending.
Well trying to get the two curves laminating would of been difficult no? Would we not of needed to make a former to the same curves of what we wanted to laminate two for the roof? and this is why we thought it would be difficult to laminate as we did not know what the curves where and so thought steam bending would of been the easiest way. The idea was to run up to the roof fix the middle down onto a rafter and then slowly bend the timber around the rafters and then screw threw to hold it down while it cooles
When I was at college, I remember seeing a video on steam-bending, and there was an old B&W clip from the thirties, in a factory where there were 3-4 guys in shirts & waistcoats with a massive press, and they were steam-bending 90 degree bends in massive (I'd guess 12"x8") oak beams! [eek]
I've looked for that clip online, but never found it...