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Question: Laminating thick boards12/2
In my current project I am laminating two boards (dimension:approx. 20"x40"x1") on top of each other. I then come in with a router and cut out a bunch of the top board, leaving the bottom board as a base. The top board has varying thickness and patterns after it is cut. I am finding that sometime the boards are not adhering completely and there are sections of the top board that will flap up. I am using PVA wood glue.
It is my guess that when that much material is cut it releases stresses in the wood as well as the boards of uneven thickness are effected by moisture and humidity changes.
The potential issues I think of are:
Insufficient clamping and distribution of force. Could this be fixed with a vacuum press?
Slow glue time because the pieces are so large and thick.
Anybody have experience laminating large/thick boards?
I haven't tried what you are attempting, but it sounds like you may have "voids" between the boards in the glue line. Are both boards prepared for gluing by abrasive sanding to get a flat surface? If there is even a few thousandths of an inch gap between the boards, you will have no chance of getting a good bond, at least in those void areas.
John, Thanks for the idea, it is quite possible that I don't have the boards completely flat and there are voids. I am flatting them with a planner or router and then sandpaper but am having some difficulty with getting them completely flat. Any suggestions on how to better accomplish this?
Normally I am a fan of PVA glue but for your situation I think it is not appropriate. Introducing water to one side of such a large surface area will induce cupping to both pieces. It is unlikely that you could keep the pieces closed enough to achieve a good glue joint. For something that large I would think you would be better off with a vacuum bag or frame press or better yet a hydraulic cold press. Choose a glue with minimal or no water, resorcinal, PU, epoxy. You will be looking at longer cure times.
Thanks for the thoughts. I am getting a vacuum bag system that should help with the clamp. I didn't consider the moisture in the glue and will look into other glue options.
If you were to use an epoxy adhesive it will be able to fill the void of an imperfect surface mate. Epoxy also does not require as much pressure as other adhesives. Based on your size (20" x 40") and without a press, I'd give it a try.