Laminating Plywood Panels Together

When gluing multiple pieces of plywood together for a built-up thickness, make sure to balance thicknesses to balance opposing stresses. December 27, 2006

I need to build up a furniture top to 1" thick and plan on gluing a 1/4" panel to a 3/4" panel, 22" by 65". Was wondering whether to use glue or contact cement, and what the best procedure would be.

Forum Responses
(Cabinetmaking Forum)
From contributor F:
I think I would use regular aliphatic resin (yellow) glue. There is some consideration about the different thicknesses of your laminates and how straight they will remain after being glued together. Plywood, for instance, is always glued up of an odd number of laminates for balance. Also, each opposite laminate is of equal thickness to the other. In your case, a half inch center with quarter inch glued to both faces might be safer than gluing 3/4 together with 1/4. There are instances where I glue parts of unequal thickness together, but usually only when it is part of an assembly that has other members that aid in keeping the whole assembly straight. In the case of a table top, the rest of the design or the table base would be the determining factor as to whether or not the top had to be perfectly straight on its own.

One tip I can pass on as far as gluing up the lamination is to use a flat surface as a means of gluing it up flat. When we glue up purposely curved parts, we use purposely curved surfaces to ensure the curvature. So, the reverse is true for a perfectly flat glueup.

From contributor X:
Using contact cement has a pulling effect on one side, thus a backing sheet on the bottom side would compensate for the pulling. Using glue requires clamping or a press, depending on what your setup is for and how many panels are needed. I would prefer glue and a press method. There are other factors to consider like finish, moisture, heat, cold, etc.

From contributor P:
I think the differing thicknesses will pose a problem - I would go with two 1/2" pieces, yellow glue, and then vacuum bag them on a dead flat surface.

From contributor C:
Good advice. Go with two 1/2" panels or 1/2" core and 1/4" top and bottom. I think the 1/2" core and 1/4" top and bottom will give the most stable panel.

From contributor S:
1" MDF.