|Forum topic by Lenny||posted 09-27-2009 04:56 AM||5473 views||0 times favorited||11 replies|
09-27-2009 04:56 AM
I am in the middle of making a cupola for my garage roof. The wood species is cypress. I will post more photos and provide details of the build once I finish. This photo shows my first dry fit. I am wondering if I need to be concerned about a cross grain situation. As you see in the picture, the grain of the four posts runs vertically (up and down) while the grain of the four boards that wrap the posts runs horizontally (side to side). In furniture making this is a classic cross grain situaton and caution needs to be taken in terms of glue and fasteners. As I conceptualized this project I pictured myself gluing the boards to the posts and perhaps adding some brads or screws. I am concerned that the boards (12” wide) will want to expand and contract up and down and if they are glued to the posts, they won’t be able to causing a crack in the board. The posts are 1 3/4” square.
Some alternatives would be to just glue a small section (say 3-4 inches) at the bottom, top or middle of the four boards. This will allow the remainder of the board to expand and contract. I have seen Norm Abrams do this on some of his projects. Of course, each post abuts two sides. Do I only apply the glue to one side or both? Another idea is to skip the glue altogether and from the post side, use two to three screws in each post drilling elongated holes that will allow the boards to move. I could also drill and screw from the outside but I would then have to counterbore and bung the screwholes. A woodworking friend suggested that this is like building a house and carpenters don’t worry about cross grain situations, cabinetmakers do.
What would you do fellow LJers? Thanks.
-- On the eighth day God was back in His woodworking shop! Lenny, East Providence, RI