Originally Posted by
brian holcombe
first thing is to forget about the ticking clock, and the wood will win every battle so it needs to become an ally.
Next, you need better prepare yourself for this job. You need a longer straight edge, a 4' isn't going to be all that helpful. 96" is where i would start, that will give you a better idea of where the edge is overall. Then you need to prepare two edges to meet. Get them close, then tune them to mate each other rather than trying to get the entirety of each board perfectly flat and square.
A slight gap in the center is needed for a tight glue up, the gap closes with clamping in the center and the edges become very tight.
I do long glue ups with a lot of clamps, two boards at a time. I clamp every 6"-8".
Winding sticks are the most important tool that the hand tool user (or any woodworker) has, use them to check your edge for accuracy to itself, not to the board face. If the board face is out of square then referencing it is useless. You'll need a general squareness, but once that is accomplished the edge needs to be flat in order to mate well to the accompanying edge.
This is the biggest area of screw up with long thin board edges in my experience. People check along the edge with a square, not realizing that the board reference face is not perfectly flat, and then the two boards won't mate well when edged up together even though they're both interpreted as square. A winding stick removes that source of error.