Building Cabinets with Prefinished Plywood
Advice on assembly methods and other tips and tricks for building cabs with prefinished plywood. April 17, 2013
Question
We're starting our first kitchen cabinet job using prefinished plywood for the box construction. We have always used unfinished in the past, but the benefits of prefinished finally convinced us to change. For shelving, how do you face the shelves - pre-finished edge band, solid face edging finished after, or some other system? If we are spraying CV on face frames after attachment to upper wall boxes, can we scuff sand the prefinished and spray over at the bottom or are we better masking off the bottom? We plan on attaching 1/4" finish end panels over ends and would be spraying ends and face frames after attachment with the inside of the box covered with cardboard behind face frame. Spraying the whole bottom of the uppers would also take care of coating the bottom end cuts of plywood, just not sure about bonding to the prefinished.
Forum Responses
(Cabinetmaking Forum)
From contributor C:
Some people do not like the look of pre-finished plywood. I have to say, though, that the last job I did my customers absolutely loved the prefinished interiors. They make it a point to show off the insides of the cabinets, to everybody who sees the kitchen. They also point out how I capped the screw heads with matching prefinished fast caps.
The cost savings practically pay for the plywood. The UV finishes they use are very tough. You're going to have a hard time finding any finishes that will adhere permanently. At best I have seen coatings stick, but you could scrape them off with a fingernail after they dried. I had a customer that tried to attach LED lighting strips with auto body trim tape, and that wouldn't even hold for more than a week or two.
To touch up minor scratches I use a little paste wax.
There are various methods for masking off boxes for finishing. A quick search will turn up some past discussions on this.
For shelves, you can go with prefinished banding, or you can mask and spray. I have heard of people stacking shelves and spraying rather than masking, which might work but it could also be asking for trouble. I have also done prefinished solid strips, which is painstaking.
From contributor J:
We use a lot of prefinished plywood on our cabinet jobs. We mostly do frameless cabinets. We use PVC or natural edge tape and stack our parts with 1/8 spacer strips between each part. Works very good for us. For the shelves I use two sided prefinished and edgeband with PVC maple. Never had any problems. We started using prefinished about 6 years ago and have never looked back. Saves a lot of time on finishing. Before frameless we were doing face frame and would use masking tape and cardboard, then finish our boxes. As for your bottoms, why not finish the bottom off on the job using prefinished 1/4 panel?
From the original questioner:
We don't do installations, so on site install would have to be by someone else. It also wouldn't address the bottom edges of end panels getting finished. We may just mask off with cardboard. I'll experiment on some scrap anyway. Thanks for the feedback.
From contributor J:
You could use PVC edgebanding on the bottom sides and use two sided material for your bottoms. Another idea - you could finish the face frames then pocket screw them to your boxes. Would save a lot of time masking and cardboarding up the insides.
From contributor K:
We've used prefinished for years. Face frames are attached with pocket screws after finish. The only place we do not use pocket screws is on the bottom of uppers (we glue and clamp). Then we attach end panels, doors, drawers, etc. We've found that 95% of our customers do not care what the bottoms of their uppers look like. The ones that do... We spray out some 1/4" ply and attach on site during install.
From the original questioner:
That sounds like the ideal way to go. Our problem right now is a lack of space. Need more room to be able to spread out all the face frames, doors, shelves, etc. Guess we'll give it a try though. Thanks for all the input. By the way, we do use pocket screws to attach the face frames at sides and top of wall cabs and all around at bases. Works well.
From contributor K:
Space... that's the best part. No boxes filling up your finishing space. We have rolling racks for the doors and drawer fronts, and larger racks on the wall for face frames and large panels. Shelves... those are prefinished too (and actually are the absolute last things made).
From contributor M:
I've been using prefinished for about a year now and would never go back. I have 20 or so carts made from 2x4s and all have casters. We finish all of our face frames on these carts. All of our assembly is done after the finishing. Not only does the time saved pay for itself, but the cost of the saved finish will more than pay for itself.
From contributor M:
To elaborate a little more. While I spray one frame on the cart, my other guy is pushing another cart over and taking the sprayed one away. All of the panel ends, bottom wall cab panels, doors, drawer fronts, etc. are stacked on dry racks. When all the finishing is done, we get the cart and take it to the assembly table that has a large soft quilt on it and the cabinet is assembled and put right back on that same cart and wheeled back to where the drawers and doors are put on and shrink wrapped and then pushed toward the trailer. Very little cabinet carrying. I might add also that I mill a dado 1/4'' deep on my finished ends and pocket hole my finished end and screw it right into that dado, then my prefinished side gets glued and pin nailed to the inside of the paneled end covering those pocket holes.
From contributor A:
When you guys talk of the places where you don't pocket screw and instead glue and clamp, I am assuming you all pre-finish face frames? If so, do you not spray the backs? How would you glue and clamp if the backs were finished? What glue? Just wondering.
From contributor E:
Using a cutting list for your cabinet sizes is the best option. Then just pocket jig using your
Kreg and fix your finished face frames and cabinets. We add a solid wood slip to all exposed shelves also, which is a nice touch.
