Edge gluing is only adviseable if the joint is not under stress as in a tube. To do so you use a strip of paper to act as a tab under neath. Glue it very lightly to the back of one piece. Then when dry apply glue to the ege of the other piece being careful not to apply too much. Apply a very thin coat of glue to the other half of the tab and press the seam together carefully smoothing it out along the seam and tab. Clamp if possible. After it dries peel off the temporary tab. This way the edges stay flat and don't warp out of shape. Personally I find it way to time consuming. I prefer just leaving the glue tab in place and working around it. But that is how I do it. Maybe some others have a better way.