"dadiOH" wrote:

I'd suggest that you do your panels in stages...glue up 3 - 10" +-
wide sections then (after drying) glue those three. Reasons...

1. MUCH easier to keep flatter
2. Less worry about glue open time.

Good advice.

Since you are using reclaimed lumber, forget a planer, time for the
drum sander.

Glue up the boards as is (IOW, if thickness varies from board to
board, NBD, you clean it up later).

Glue up as flat as practical, scrap off excess glue when cured, bring
to desired thickness with a drum sander.

A commercial drum sander can handle 48" wide panels.

After sanding, get piece installed.

If left laying around, will probably warp.

Have fun.

Lew