Gluing laminate to plywood

Question

I just got laminate wood cut and it’s wet. I’m drying it inside stacked with spacers. If this is wrong please let me know! I bought Grip Bond 4 to glue it to plywood after it dries. It’s for an interior door. I’m just guessing what to do at this point. Am I doing it right?

Answer 1

Addressing the gluing-to-plywood question, once you get the "laminate wood" dried:

If I understand correctly, you want to make an interior door with a plywood core and a laminate wood face.

The trick with layering different substances together on a panel is to do the same process on both sides. Whatever you glue to the front, you glue in the same fashion to the back. Otherwise, the slight differences front vs back will cause different stresses, and the panel will warp.

The following assumes that this "laminate wood" is a single large surface that fully covers the plywood core:

You will need a true flat surface or table, larger than the door, that will support substantially more than the weight of the plywood and laminate faces, and remaining completely flat under some hundreds of pounds of weight.

Place the back piece of laminate wood face down on the table, with a protective sheet of paper or plastic under it so oozed-out wood glue doesn't glue the door to the table. Pour glue on the back of the laminate wood. Use a comb-like spreader to spread the glue around. Do this quickly: Grip Bond 4 is a wet wood glue, and you need to make sure the glue is still all wet when you lay the laminate wood on the back. Once the plywood is in place, glue and comb the top face of the plywood, then lay the front laminate wood piece on the top of the glued plywood.

The next step is to make sure there are no air pockets in the joint between the laminate wood and the plywood core. Flip the door so the back is up, and use a rubber roller to roll from the middle to the outside edge, all over the back of the door. Some glue will ooze out, that's OK, as long as the glue was all wet when the ply and laminate were put together. Flip the door again and roll the front of the door in the same way.

Cover the front of the door with a protective piece of paper or plastic, then place another piece of plywood on top as a clamp. Place heavy weights, like 5-gallon buckets of water, weight-lifting weights, etc, all over the top of the clamping plywood. Note that the ply core may start sliding sideways as the weight is added, watch for this and push everything back aligned. Monitor this possibility of sliding as the glue dries. And be sure to check the plane-ness of the table you're working on: it has to stay flat under the weights, or you'll glue up a curved door.

A different option for weighing the clamp plywood is if you can get access to a large enough vacuum press bag and pump: slide the glued door and 2 pieces of clamp plywood one on top of the door, one below the door, with protective plastic or paper between, into the bag, seal the bag, and turn the pump on. This will apply great pressure without all the extra weights pushing the work table down.

Note that your materials may not be the best for the project: The usual sort of thing to use for a laminate-finished interior door is an actual solid- or hollow-core interior door and phenolic-backed veneer or actual countertop laminate. Plywood can warp over time. And the glue-up process is prone to trouble that gets easier to handle the more times one does it in a cabinet shop for 20 years as one's job. A standard interior door is designed to remain flat for many years. And thin laminate or phenolic-backed veneer can be applied with contact cement, which while requiring its own set of cares to apply correctly, does not require long clamping times or sloppy wet glue oozing out everywhere.