Is there a maximum width for each board if you are edge-gluing them together to make a panel?
Ellis Walentine: Nope.
Ian Kirby: There is no maximum width of board when you are edge gluing. Here’s a couple of points that might be helpful. The wider the boards, the fewer clamps you need. The pressure from the clamp shoes fans out at about 45 degrees on each side of the clamp. If you plot this fan line to the glue line, then the pressure will be the same along that area of the glue line. This plot also tells you where to put the next clamp ? or how many clamps are needed.
The glue will transfer from one edge to the other, so you could put glue on one edge only. A better method is to spread a very thin layer on each edge using a 3″ paint roller. You should aim to get a fine ribbon of squeeze out on the glue line – not a dripping mess. Too much glue on the edges has the boards skidding about until you have squeezed out the excess. Position the clamps with one on top and then one on the bottom. Use a straightedge to check that the boards are flat, one to the other.