# edge grain joinery



## harum (Nov 25, 2013)

Hello! I would like to build a hardwood table top, 26"-by-40", by edge-joining several boards, which I had never done before. Namely, I would like to do a plain butt glue joint or edge glue joint. Having done some reading on joinery, I am not so sure if I can make a reasonably seamless, lasting DIY table surface: even boards of the same wood species can fail in edge-joining due to cupping, uneven shrinking, glue "creeping", etc.; and I would like to use two different species in the same surface.

What are the dos and dont's in edge joint gluing for getting a flat, smooth and durable surface?

Here are six factors I can come up with that are important for preventing edge joint glue-up failure. I am sure that the first one is a must, but how important are the other?

1. surfaces should be square and true;
2. quartersawn boards preferred over plain sliced;
3. use "sprung" joint;
4. glue choice is important;
5. watch "heartwood" side orientation in boards.
6. other kinds of joints are preferred: tongue and groove, splined joint, biscuit joint, etc.

Any comment or reference to a book chapter covering these questions would be greatly appreciated. Thanks.


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## CharlesA (Jun 24, 2013)

Butt joining can be a problem in strength, but a good glued edge joint can be very strong. 
1 is important
2 lots of strong joints with flat sawn boards.
3 can good but lots do without it.
4 Plain ole original Titebond will give you as strong a joint as anything out there-no need for exotic choice. You can use Titebond III if water resistance is a big issue, but lose a little strength.
5 there are different thoughts on this out there.
6 biscuit helps with alignment, not strength. I wouldn't waste energy on the others.
7 you can use supports beneath the table top, pieces screwed in perpendicular to the top orientation with counterbored holes (allowing for wood movement).
8 Cauls. Good Cauls http://www.highlandwoodworking.com/woodnews/2010april/cauls.html
9 I'd glue up something much smaller to get some idea of the technique before tacking something that size


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## dbray45 (Oct 19, 2010)

Tongue and groove the meeting edges, it will give you better strength. You really want to offset boards so that they "feather" and not have two boards butted together.

to illustrate (if this works)
- --- ---
-- -----
---- ---


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## pintodeluxe (Sep 12, 2010)

Here is a thorough explanation on building flat panels. It starts on the 8th picture in the blog. 
http://lumberjocks.com/pintodeluxe/blog/33797

I think spring joints are overrated. Just get the edges good and straight, and you will be fine.


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