Replies

1. 
   pantalones868 | Dec 15, 2021 07:46pm | #1

   Floating breakfast bar...like in the pool?
   Mechanical fasteners can't hurt... You'll be gluing end grain to end grain and the last thing you want to do is restart that discussion! Dowling for alignment and it will create at least some surface to glue to.

2. 
   jharveyb | Dec 15, 2021 07:47pm | #2

   Not sure if I can help, as there are some unclarities (i.e., what is "floating"?) If you miter, spline, and glue two pieces of butcher block together, they should stay together well if both are subjected to the same seasonal humidity variation. What will NOT stay the same is the angle that they make in the corner (assuming that they are not restrained from below; if they are, then the joint can break from the stress.) As the butcher block expands across the grain in a humid summer, the 45º angle becomes less, and the corner angle increases. Opposite if the wood dries out more in the dry heating season. So if the top is unrestrained and it's OK for it to change shape, all is well; if restrained, likely trouble.
   I made my own kitchen counter tops from "butcher block" (really, strip laminated) cherry, with one end being a short ell. Instead of a mitered corner, I just glued a short, wide piece of the butcher block to the long counter top to make it essentially wider at that end. As long as you make allowance for the top to change width, all will be well. Not sure if I would do this if both legs of the ell were really long, tho.
   Another option would be to use the fasteners and biscuits/splines to make a 90º butt joint between the two pieces, instead of a miter. As long as you keep the front edges of the pieces square (not rounded over), and allow for the seasonal movement, all will be fine. The piece (B) that butts into the other (A) can change width, without changing the overall shape. You just need to finish the front edge of A before you assemble the two, so that if B shrinks, there won't be an unfinished little strip exposed. Note that B will need to be allowed to move in both directions, if A is fixed at the wall and allowed to move at its front.

3. 
   _mj_ | Dec 15, 2021 08:49pm | #3

   Post a drawing, way too many options for floating, mitered, L-shaped, and splined. Show us your application so we can help instead of guess. The more detail the better.