Joining and Gluing Boards on Edge
at the June 11th Guild Meeting
The June Guild meeting at Woodcraft highlighted the requirements, techniques and choices for successful edge glue-ups, resulting in a wider board.
To ensure success, Ken Gregg
stressed that the edges to be joined must be flat. Using a well-tuned jointer works well. To ensure a straight/flat edge, the ideal technique is to apply pressure on the stock initially on the infeed table, then finish the cut with pressure on the outfeed table.
Other techniques include table saw with a sled, routers, and hand planes.
Jim Milam
discussed and demonstrated hand plane usage, with the ultimate objective to achieve a very slight concave surface, commonly referred to as a Spring Joint. Begin by planing the edges, then proceed by marking one inch from each end of both boards. Then plane between the marks until no more shavings are produced. Finish by planing 1 pass over the entire edge. Practice !
Given the slippery nature of wet glue, in combination with the challenges in keeping the boards flush as the clamps are tightened, various tools & techniques can be used to ensure that the faces of the pieces glued-up are as flush as possible.
John Jones
discussed the use of biscuits and dowels to properly line-up the edges, with biscuits being his clear favorite of these two methods.
Tom Melcher
discussed and showed his Festool Domino. It is typically used for mortise and tenons, but works very well in lining up edges. Sort of a biscuit joiner on steroids.
Ken Gregg
showed the use of stretch tape, as a very effective method to clamp thin pieces.
The use of cawls , typically running perpendicular to the clamps, is also a way to help ensure that the edges are lined up. Practice required.
Finally, Jim Milam
demonstrated the rub joint technique, which can be used for special needs, with no clamping required. After applying a moderate amount of glue to both
edges, rub the pieces together fairly vigorously for a few seconds, stop, and let them dry.
As is shown in one of the photos below (taken by Jim), about 12 hours after the meeting he attempted to break the glue joint with a hammer. As you can see the glue joint held and the board failed along the grain. Six days later, same hammer - same result: another failure along the grain !
It was an excellent presentation and very informative meeting on the important skill of edge gluing. Thanks much to all the gentlemen for their excellent presentations !