How coarsely sander will glue well?

[Wade Lippman]

I am making a end grain cutting board. I have made the first board and sanded it flat in a drum sander. How fine does it have to be to glue well? Or doesn't it matter?

[Mel Fulks]

I think the most important thing with "flat gluing" is putting glue on both surfaces. If you are using a PVA glue I would thin it a little. No more than 4 percent water. For the pre glue sanding I'd use 100 grit, but it depends on what kind of wood,
too. If you use too fine a grit you might burnish the surfaces, and that is bad .

[glenn bradley]

I routinely glue up these sorts of things right off the tablesaw.

391550

From the makers of Titebond:

"The preparation of the stock to be glued is extremely important. Joints cut fromrip saws should be free of saw marks. They should also be straight and square.Moulded or jointed stock should be free of knife marks. Glazed or burnishedjoints will prevent adhesive penetration and should be guarded against. Whenpossible, glue joints should be prepared and glued the same day"

End grain cutting boards rely completely on the glue bond for structural integrity. If the surface feels relativly smooth I would say you are good. If there is any question and you want to avoid callbacks, move up another grit.