We are doing a large project with lots of paneling. The panel sizes range from 8wide x14 tall to 14 wide x 18 tall all white oak. We are using old growth oak with knots, splits and some new quartersawn oak as well. We dont want to just rip and glue back a bunch of wood panels with joints every 4 We are trying to make outstanding looking panels. We want to split 4/4 and butterfly the panels 1/8 thick. Then glue them to a 1/2" oak core with 1/8 oak backer (balanced) all the wood is close to the same moisture content between 6% and 8% at this time. Does anyone think we will have any problems with splitting?
(Architectural Woodworking Forum)
From contributor L:
I don't see any problem. I am curious why you are aiming for a 3/4" panel? But, back to the panel construction - the shop next to me made a very nice china hutch from white oak. They re-sawed 4/4 into 1/8" and laminated it over 1/4" core. It made for very stable, nice panels, and allowed for all the panels to be made from a single board.
When re-sawing the 4/4 into 1/8" pieces (I hope you do not mean that you will actually be splitting the wood, but you will be sawing it instead), if the lumber was not properly stress relieved (that is "conditioned" to remove casehardening), you will not have flat 1/8" pieces. It would not be a good idea to try and flatten the pieces while pressing to the core.
Most people would use a non-oak core in order to save money and weight, and to have a flatter door. One potential problem with an oak core is that if you have some pieces that have sloped grain, when their MC changes, they will twist and warp, causing flattness problems with the door.
Back when I first started in the 70s I glued some 16" wide, oak panels to a slab door. One year latter I replaced the oak panels .They shrunk and split and I dont know what the moisture content of the oak or the doors were (the shop was in Houston TX so I am sure it was high). I was just worried about that happening again. Would using a plywood core keep the oak from expanding?
We are being careful with moisture this time, all will be 6% to 8%. We have the heat on and the air has been very dry. The houses were all the panels will be going will have heat and AC during the instillation. Our shop on the other hand does not have AC and when the weather turns wet and warm I am worried about problems.
In short, you must control the MC and make sure that the components are at the correct MC when assembled, using a MC meter. (In most cases, the maximum MC for the wood should be 6.5% MC to 7.0% MC, but it depends on the final environment's conditions). You should also use a finish that will restrict moisture (vapor) movement, so that any changes in MC are slow and more even, face-to-core.
Finally, the customer must recognize that wood is a dynamic product and some changes will occur even with a perfectly built door (including a top notch finish) if the RH changes quite a bit. We cannot change the properties and behavior of wood in a changing environment.