Hey Malc, I do glue up narrow board to make wider ones. You need several clamps that are wide enough to span the width of the boards. The glue edges need to be perfectly flat or straight, otherwise you will have a visible gap in the final board. If you have parallel clamps such as Bessey's, you can glue the panel directly onto the clamps. Apply a thin layer to each joint then tighten the clamp jut tight enough to get just a little squeeze out. You may want to use smaller clamps to clamp the panel to the Besseys so it will stay flat while the glue dries.
If you don't have the parallel clamp, Lay down some waxed paper onto the work area. Apply the glue as above, then clamp the panel up flat on the waxed paper them clamp. Use some weights or brick to keep the panel flat while it dries.
After about 10 minutes, scrape off the glue before it fully cures. That way you wont have to scrape off dried glue.
Good luck!
