This is how I would make the curved ends. I would use the method I used for my very first laminating project; the curved elements of this bed:-
It's a method that can be done at leisure, ie, no panicking to get clamps in place.
A few preliminaries:-
1. The 400mm height is a big ask. I would make 4 x 100's and stack them up.
2. A former is required and I would make it oversize in height, say 125mm
3. The oak laminae need to be oversize, say 110 to allow for cleanup after gluing
4. Use a glue with a long open time and hard-setting, ie , not PVA. I've used Cascomite in the past but Aerolite is the one to go for these days.
5. I don't think steaming is a good idea. In my experience the the oak will distort and make the laminating process unreliable.
6. Good quality straight grained oak will be needed.
The method:-
1. Make a pattern out 6mm MDF. It'll be easy to make this one by bandsaw or jigsaw with hand sanding to finish.
2. Use the pattern to make a number of layers out of thick MDF; enough to stack up to the 125mm height. Router table or spindle moulder required
3. Make a number of clamps made from threaded rod and wooden blocks:-
4. Clamp the set of laminae centrally to the former. It will pay to have the laminae taped together to keep them in line. Also cover the former with parcel tape to stop any stray glue from adhering.
5. Start the bending process
I've only shown one more clamp here but it would be best to keep the whole process symmetrical and use another clamp on the other side of the centre line . Tighten each clamp a little at a time.
Notes
1. With this method there is no need to do all 4 laminae at the same time. The first 2 can be done and then the final 2 can be added afterwards (or one at a time). This will reduce the clamping forces considerably.
2. Make sure the laminae plenty long enough. Take account of the extra length of the outer layers and add some more..
3 The clamping needs to done well beyond your final design cut off, say another 50mm.
4. It's always difficult to make a good transition from the curved section to the straight bit, so ensure the is a concentration of clamping in those areas.
I hope that is food for thought.
Brian
