I'm planning on making a heavy bench top by using six 4"x4"x6' posts, and gluing the faces together with Elmer brand carpenters glue and several large bar/trigger clamps. Afterwards, I'll just manually plane the top and bottom of the board to smooth it out and remove the excess glue.
For the support posts and the bench top, is there a specific type of sealer I should apply that won't compromise the glue's bond? I am installing this in the garage in a humid area, so I'm using a 1" raised post base to keep it off the ground in case of spills:
And then I will be connecting the top half of the support 4x4 posts to the bench top with adjustable deck support brackets so that I can perfectly level the desk in case the top is flat but at an angle, or if the posts aren't cut to the same lengths:
I am also concerned about the sealer causing an interaction with or oxidation of the metal parts.
How should I proceed choosing a sealant/stain? For what it's worth, would tung oil be a good choice?