Flat Slab Cabinet Doors

Given the concern over quality of sheet goods, what's a practical way to make large, flat cabinet doors? Here's a handful of suggestions. September 7, 2006

I have I client I've been working with for several years. He has asked me to do a project that would have 24" x 72" flat doors that have to match the look of pre-existing cabinetry found elsewhere in the house. The cabinetry is all Birch and I have done other projects for him using the same wood and style etc. In the past I have done the same construction as the older doors - veneer core ply with solid edging for the doors and solid birch for the drawer fronts. I am doubtful that I can find ply flat enough to make doors this size. Solid wood is an option, but the cabinetry is Euro style and I'm thinking the seasonal movement will be too much. The house is located in the northeast, about a mile from the ocean. Is there anything I'm missing? Is lumber core ply (blockboard) any flatter than the VC? What about laminboard? I think an MDF core probably won't hold up over time. I don't have a hinge press, and screws don't seem to hold well in MDF. Thickness should be between 3/4" and 1". My client wants these to be high quality, so I could use any suggestions you guys have.

Forum Responses
(Cabinetmaking Forum)
From contributor A:
I think that the optimal solution would be 1/2" honeycomb core with lumber rim and 1/4" skins - MDF or VC if you want the extra screw-holding out at the skin. It would be a nice flatness and weight proposition - expensive though. A less expensive option: sometimes pressing two layers of Baltic Birch gives you a little flatter panel than your average VC panel.

From contributor B:
I have used MDF veneered both sides successfully for this application. Blum sells a hinge boring machine called the Ecopress for around 250.00 which will do the same thing as a full boring machine. It comes with the bits and is very easy to use. We have one for emergencies when a door is miss-bored or we have to install a cabinet before the doors arrive. It works with a cordless drill. Use Inserta hinges for ease of finishing and delivery.

From contributor C:
I would use MDF and use the Blum Inserta hinges. They will hold the door securely and will not have any screws to strip and pull loose. That combination will give you the flattest doors with the most adjustability.

From contributor D:
If thickness is not a problem than perhaps you should try using a commercially available 1-3/8" solid core birch slab door, 24" x 80", then just cut it down in height and install it with standard door hinges. If you need self-closing action you can use spring hinges. I have also seen this used with a SOSS type hinge to not have exposed hardware.

From contributor E:
I agree with contributor Cs response. For the hinges, all you have to do is make sure the holes are in the right location and drop them in. Use the appropriate number of hinges and you will be fine.

From contributor F:
Youre correct about the ply not staying flat, and the MDF can be very heavy. Have you tried Procore or Armore Core? They are a 3 layer ply core with a 1/8" layer of MDF before the veneer. There is significantly less weigh and strength of ply to go along with the flatness of MDF.

I build a lot of large doors and panels (some 85 by 64, two bookmatched sheets glued up) on a regular basis and find this product the best of both worlds. I find it a much better to sand and stain than ply core. Make sure it is not made with K-3 before the veneer as this often shows through.

From contributor G:
I'm probably opening myself up here, but since no one else is willing to say it particleboard. You can't beat it for flatness and stability. Particleboard has a bad reputation that is just not justified. Too many people building boxes on their living room floor from IKEA are the cause. Get yourself a good quality 3/4 inch particleboard. I like Rosecrans myself. Sometimes I will take raw particle board and start by banding the edge with solid 1/4 strips. Then I lay up the commercial veneer in a vacuum press. This way the edge is extremely strong (edge banding tape just doesn't seem to hold up on particleboard when used on a door). I stay away from MDF except for fielded flat panels. I like that the 1/4" MDF is actually 1/4"!