Every time I talk to my plastic lamination outsource vendor, he gives me shit about how I make Formica laminated commercial cabinet doors. Instead of going through all the trouble of having him laminate plastic to one face of particleboard and white cabinet liner plastic to the other, I simply contact cement the plastic to one face of two-face melamine particleboard, trim, and edgeband. The result looks exactly the same as what the laminator gives me, and is considerably cheaper given that the white liner is omitted and the whole operation involves no press time.
He claims that this is not a balanced panel and will surely warp, but I have done this hundreds of times and never had a warp any worse that you can get with his "proper" method. Does anyone else do this?
From contributor P:
My very first Formica kitchen was built the way you do your doors. The material back then was called Kortron. It had a shiny white baked-on finish on one side and plastic laminate applied with contact cement on the other. It warped, so I started balancing the panels. If your mileage varies it is only because you are lucky.
I studied the time to pull a sheet on melamine with paint grade on one side and melamine on the other, opening the box of p-lam and laying it up, trimming and then walking it to the saw, versus buying pre-laid up with a liner, set at the saw, and the conclusion is absolutely obscene. We expend waste of 30.00 in labor doing it ourselves rather having it done for us. On 40 sheets, that's 1200! And on a job that size we cannot afford delamination, warped panels or the loss of time on the labor, when it can go to many other areas.
Fact is, pre-lam is cheaper than doing it in house, and you get a better product because they use hard glue, not contact.
Maybe my laminator is ripping me off. But I am prone to think that there is just as much labor for him to spread glue on two sides of PB, stack the panels in his press, take them off his press and onto his beam saw to cut to size, and then strap all the pieces and send them out to me. And maybe I have always gotten away with this because I always use two face melamine (not paint grade back or one sided) and solvent based contact cement. I was always told that Formica laminate was developed to have the exact same coefficient of expansion-contraction as wood itself.
One final point: I have actually on occasion used my laminator for big door jobs, and I have experienced some warping even then.
You have to balance the panel with the same thickness material on both sides. Instead of cabinet liner you have to use 949 of the same thickness as the face.
I doubt the comment about contact cement, as that has not been my experience. I mean if you just put a sheet of particleboard in the sun, it will warp because of the difference it causes in moisture content.
We just ordered 20 .75 x 4x8 sheets to finish out a job. Lam one face, liner back (not ideal, but the customer specified). Price was $68. 3/4" particleboard core, Wilson VG lam, white cab liner. I don't see any way we could beat that price in our shop using contact cement. You guys must be a lot faster at laminating than our guys.
I made a relatively small investment in used panel layup technology, and found that we could make balanced panels less expensively than melamine backed panels. We went from 12-15 minutes per side spraying and laying contact to about 4 minutes for 2 sides. We buy white V Grade in bulk and core in bulk so we get good materials prices. The PVA glue we use is about a third the cost of contact. It's also non-toxic, non-flammable and has no VOCs. The glue line is hard, not flexible like contact, so there is no shrinkage from side to side. We can do 150 panels in a shift and we often laminate for others. Among the other benefits of this system is that we moved to miter-folding most of our straight laminate countertops, so we lay up countertop blanks and have cut our counter assembly times in half. All in all, a very positive evolution.