When gluing up a large panel, will alternating the ring pattern prevent the panel from warping in the future?
Maybe, while it does not hurt the panel but it does not prevent the panel from warping.
The real culprit is changes in the moisture content of the wood. If the moisture content of the wood stays the same from the time the furniture piece is assembled to in the home where it will live. There will never be any warping, expanding or shrinkage.
Most hardwoods have a one percent change for each four percent change in their moisture content. For example, a twelve inch wide board whose moisture content increases by four percent will expand by 1/8 of an inch. It is unusual to have a board’s moisture content to change by this much, unless it was not dried to a low enough moisture content.
The best way to minimize warping is to measure the moisture content of each of the glue up boards before assembly. Know the limitations of your moisture meter.
In a dry woodshop the outside of the wood will have a lower moisture reading than the interior. This is especially true when working with relatively fresh wood with a high moister content.
Finishes have an effect on a panel warping. On most panel applications one side is finished with stain and a sealer and the other side is facing the interior of the piece and is not sealed. The unsealed side of a panel will be affected by significant changes in the relative humidity of the room.
To reduce this potential problem, seal all surfaces of the project including the hidden ones.
May 28th, 2008 at 3:07 pm
You present some good points. I live in the NW and just picked up an old dining table for the top. It is made of 3X hardwood pieces glued on the edges. It spent a day outside in the moist air before I got it.It bowed 1/4 in. over 15. I’m drying it with a little weight applied and most of the bow is gone after only 2 days. I will seal all sides of it bring it back to life in my project.