MDF Versus Plywood for Cabinets

Cabinetmakers discuss the characteristics of MDF, and describe assembly methods. September 22, 2005

Question
My company has an assignment for a kitchen. We had Anegre MDF panels made and are at the stage of building the uppers. We usually use plywood for the boxes and would like to hear any thoughts on MDF for upper cabinets and different construction techniques. Does anyone have any suggestiong?

Forum Responses
(Cabinetmaking Forum)
From contributor P:
MDF uppers are fine, but it would be easier to pre-finish the interiors before assembly. I like to use dowel joinery for MDF or melamine, and pocket screws to fasten the faceframes if that’s what you’re building. MDF accepts edgebanding really well too. I like to use 1/2" rear panel to fasten through, as MDF is heavy, plus it’s easier to use than making back rails.



From the original questioner:
We have glass doors and MDF doors. The boxes have no face frames just 1/8" edge band. We are using Blum hinges - I am concerned about the holding power of the hinge fasteners. We would use the Euro screws, available from Blum. I think they are like the confirmats – does anyone have any thoughts?


From the original questioner:
We have two construction techniques we are looking at. First, dado the sides at the top and bottom and glue in cross panels - no fastenings. 1/2" MDF back and a solid stock cross piece top and bottom at the cross panels. Second, we biscuit the cross pieces with butt joints and included the solid stock cross pieces at the top and bottom. What does everyone else think? Hinge fasteners as I mentioned in the previous post is the next concern.


From contributor R:
I’m not sure if I agree with some of the ideas so far. We use MDF on a regular basis, and have never ever had a problem. We screw our boxes together. Just use the right pilot hole and stay 1 1/2" away from the end and you are good to go. We offer a lifetime warranty with our cabinets and have no doubt MDF cabinets when finished right will hold up just fine.


From contributor M:
To contributor R: I'll keep your assembly tips for MDF in mind. I have a charity case coming up soon that I'll likely be using MDF for, which would be a first for me as I'm used to plywood. Do you generally use raw MDF or MDF core melamine?


From contributor R:
We generally will use raw MDF for paint grade work or Veneer with MDF Core when we have to order in any veneer. In fact for much of our work we sell it as superior to plywood (straighter, holds screws better, no telegraphing, more dimensionally stable). Our melamine is a Particle Board Core. You guys can say everything you want, but I've only had 1 cabinet fail from MDF or particleboard and that was a 45" wide cabinet and when I picked it up from the 3/4" x 4 1/2" front stretcher the stretcher broke where the screws held it to the sides of the cabinet (however, I've probably built another 100 this wide and never had it happen other than this one time).

This was still when the cabinet was in the shop. I just backed out the screws and cut a new stretcher. Furthermore, I set a scrap piece of PB on top of my forklift to keep the seat dry - that was 4 months ago and it went through rain, snow, and sun. Sure it's thickened some - just like plywood or real wood would have done but it looks good. Now I know no cabinet I ever make, including the most leaky sink ever is going to put that kind of abuse to my cabinets. And 80% of our customers can't get enough of the melamine interiors.



From the original questioner:
To contributor R: What size screws do you use and what size pilot hole?


From contributor R:
#8 2 1/2" ultimate square drives from HDL. I use four on either a 24" or 21" deep base and 3" on an upper. Also use the 1 1/4" for our plant on back. Use either a 7/64 or 1/8" pillow hole. I use the bit and countersink in one, although the screws have nibs and about one in eight will cause damage to melamine/MDF at the edges.