I prefer Titebond III for that kind of assembly. Using it will allow you extra time for getting everything clamped up. And it will help prolong the longevity of the piece since it will create a waterproof set of joints in case it has to survive a flood someday.Good evening from Middle Tn. I'm planning to build a 6' diameter table from walnut. It will be1-1/2" or possibly 2" thick. How would ya'll join boards together?
Good point about waiting for glue to dry before sanding. I had a panel shrink where the biscuits were placed. Unfortunately I had already sanded. It was not terribly noticeable and we had a TV on it so it wasn’t a redo. With thick boards it may not be an issue but with 1” boards it was.Two boards edge glued together is the simplest of woodworking joints and one of the strongest when well done. That doesn't say doing it well is easy. The edges need to be straight, smooth, of equal porosity, and clamped with adequate force. It's good practice to cut the pieces roughly a bit oversized and then let them acclimate. Newly cut end grain in particular will shrink or swell in response to humidity. Let it do this before you try to make precision straight edges. You can get good edges with a table saw and carbide rip blade, a jointer, or a long hand plane with practice; but the movement of the wood past the cutting edge has to be smooth, with even speed, and closely controlled for best results. For 50psi (less than 1/3 the pressure recommended by glue manufacturers), a joint 2" wide and 72" long requires 7,000 lbs. of force. You will need some heavy clamps. Let the glue cure for a couple of days before you smooth the surfaces. Water based glues need some time to dissipate or you will end up with shrunken glue joints.
kiln dried For 9 months?keep the 2" thick boards in the shop for minimum 9 months.
regardless of how you join them, if they warp twist curl cup misbehave after glue up - you'll have an expensive potentially non-fixable problem.
one totally dry/stable - 4 square the boards. I'd do biscuits, but that's just me.
Assuming you have a jointer and can machine good joints I would lay out the radius on the boards as they lay dry fitted. Then well within the radius I would dado the boards and insert a spline in the joint. A round top you could never reglue if one of the joints were to fail. A spline would secure the joint better than anything you could do. If you ran the splines within the radius nobody would ever know they were there.Good evening from Middle Tn. I'm planning to build a 6' diameter table from walnut. It will be1-1/2" or possibly 2" thick. How would ya'll join boards together?