Kitchen Cabinet Question

[Jeff Wright]

I am building the refrigerator surround in my kitchen remodel job. The photo shows one side of the cabinet where I built a paneled structure (shown lying on a piece of ply I am using for a table surface for assembly) using 7/8-inch thick poplar for the rails and stiles and 1/4 MDF for the panels (all will be painted white).

My concern is the panel structure by itself is not strong enough. I thought I would face the back side of the entire panel with 1/2-inch ply to give it added strength (plus dress up the inside of the refrigerator cabinet). My concern and question is if attaching that 1/2-inch ply with screws will cause problems should the raised panel expand and contract. Would that risk breaking the rail and stile joints since the ply won't move with it?

[Jamie Buxton]

No problem. The MDF isn't going to expand and contract, so the overall dimensions of the panel will not change significantly. You can fasten plywood to the rails and stiles without worry.

(Incidentally, you called the MDF panels raised. I don't see any raising.)

[Jeff Wright]

No problem. The MDF isn't going to expand and contract, so the overall dimensions of the panel will not change significantly. You can fasten plywood to the rails and stiles without worry.

(Incidentally, you called the MDF panels raised. I don't see any raising.)

Good catch Jamie. While the 1/4-inch MDF panels themselves are not raised, I used a cope and stick bit set to apply an ogee on the edges of the rails and stiles to give the appearance of raised panels.

[Philip Rodriquez]

If you are concerned about the strength, you can simply glue the panels in place. You will be amazed at how much more rigid it will become. As Jamie mentioned, MDF is not going to move on you - therefore, there is nothing to worry about.

[Jeff Wright]

It's not the MDF that concerns me; I recognize that MDF is stable (and can be glued in place).

While the rails and stiles of poplar are not that wide (2.25 inches), my concern was more the poplar expanding and contracting and be restricted by being screwed into the underlying ply panel. I wasn't sure if even that narrow of a piece of poplar would expand and contract to cause the rail/stile joints to crack.

[Sam Layton]

Jeff,

Why not just use a 3/8" MDF panel, or a 1/2" for that matter?

Sam

[Chip Lindley]

Only 6.75" of cross grain horizontally, and 9" vertically to deal with Jeff. If anything, over time you may see shrinkage in the poplar frame rather than expansion. Fridge compressors expel lots of dry heat.

[Jeff Wright]

Jeff,

Why not just use a 3/8" MDF panel, or a 1/2" for that matter?

Sam

Sam, my cope and stick router cutters do not provide the longest of tenons, so my concern is strengthening those joints and minimizing the chances that they fail. That is the purpose of skinning the panel's back side with a separate ply panel. Going with a thicker MDF would not appreciably strengthen those joints in my opinion. I could be wrong.

[Andrew Pitonyak]

Let me repeat what I think that I am reading (learning moment for me).

The MDF panel will not expand and contract.
The ply wood will not expand and contract.

I am with you so far.

The rails and styles will not expand and contract, so connecting them with screws to the non changing ply is not a problem... OK, that I did not know.

... think think think ....

Wood expands and contracts perpendicular to the grain lines. Styles and rails are cut so that the grain runs lengthwise, so, the changes are along the narrow part of the wood. End result is that I expect change, but, minimal change.

About 1/16" per foot with a width of say 2 inches yields but there are two pieces... OK, that is about 2 thousandths. Very interesting. Never thought about it.

[Bruce Gray]

I recently completed some cabinets with pretty much the identical situation... poplar frames with MDF panel attached to plywood cabinet boxes. (Except I used 1/2" MDF instead of 1/4"). The stiles were mostly 2-1/8", and the panel assemblies wiere glued and screwed to the plywood boxes. I made about 10 cabinets with this construction. These were all built last summer (in a non-air conditioned shop), and have endured one winter heating season in Western Pennsylvania (and what a winter it was !!).

Everything survived fine with no cracking of the rail to stile joints.

I would think would be no concern at all doing the same thing in Florida (where you don't have the dry heating seaon the contend with.)

[Philip Rodriquez]

At 2.25 inches wide, wood movement is not a concern - I promise. ;) However, screwing in to MDF can cause problems because MDF does not hold a screw very well. Glue will get'er done!

[Joe Chritz]

You should be fine connecting the panel to the plywood. There is some width expansion but it is very minimal on a piece that small.

Secondly I seriously doubt that it is needed at all. Glue in the MDF panels and that will be plenty strong. Even if it is required to hold some weight it is a very strong set up.

Joe

[Jeff Wright]

I've decided to install a half-inch ply against the inside face of the panel side to the refrigerator cabinet shown in the attached photo. It will dress up the inside making it look like the opposite inside side as well as add some stability to the unit. Thanks for the comments in answer to my question.