I want to have someone make me some cabinet doors that are for wardrobes in a master suite dressing hall.
All are about 24 wide by 59 tall, flush/flat, veneered front and back, and edges.
I think I should specify MDF cores. Is this the right material for this application?
See the attached pic for more detail.
Replies
Hi Stinger,
3/4" MDF will certainly be heavy, and could good and truly smash one's finger! At 59" tall, I'm not sure if they'd remain flat over time.
I would give torsion boxes serious consideration because they'll weigh a heck of a lot less, and be dimensionally stable. My concern would be fabricating them with solid material positioned to accept 35mm cup hinges and other hardware - but that's really just a matter of planning.
Good luck,
-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
I agree. I think torsion boxes would be a good choice to balance, weight, strength and dimensional stability.
Glaucon
If you don't think too good, then don't think too much...
I understand the basic concept of a torsion box (lattice with skins), but I'd not known to consider them for a door. Can you recommend a book with a good discussion of the torsion box and its uses? I've not seen much in the many books I've read...
Thanks for any help!
I can't think of any books offhand, and I'd be interested in what others who have built suich doors would say from their own experience. As was pointed out, hollow core doors are torsion boxes. Even those that are low cost HD items made of luan may not look great, but they do tend to stay true.
I'm not so sure about MDF in an application where it will tend to cantilever its own weight. It tends to sag in tension, and it is quite heavy. It wouldn't be bad for raised panels along a wall, but I'm not sure its weight is such a great thing in a door.
I would guess that if you were fastidious you could build the frame of the box with solids, and join it with sliding dovetails or M & Ts (I wouldn't trust dados in a door). You might want to use thicker frame members to accept hinges. You would rabbet the inner rim of the frame and inset veneer plywood on either face. I thnk this would be light, strong and not prone to racking.Glaucon
If you don't think too good, then don't think too much...
Forget torsion boxes for this application. They are 24" W x 59" H cabinet doors, smaller than you see on a lot of kitchen pantry cabinets.
They are to be nominally 3/4" thickness, and with their veneer finish, the choices are some kind of plywood, or MDF.
What should it be? I compute that with MDF cores, each door leaf will weigh about 25 pounds, which is under what Blum says should be the max for a 60" tall door hinged with three of their cup hinges.
I've done slab doors bigger than this using MDF and they're fine. Are you using pulls or touch latches? Either option could use magnets to hold the doors flat if necessary.
See my first reply. I've used mdf before and will do it again. I would choose mdf over ply, for these doors, because I'd anticipate a flatter door initially and in the long run (I simply cannot believe that it will sag in time) with mdf.
A torsion box will only be as flat as the fabricator makes it. Should you choose to specify this, be sure to include the "flatness" tolerance. This may be difficult to do, enforce, and verify. I have hung many interior hollow core doors (these are torsion boxes) that were not flat. An additional concern will be to specify the core spacing. Too wide of a spacing cannot be placed into a vacuum press for fear of crushing.
Hi Sapwood,
I agree: those are valid concerns. What kind of process do you typically follow?
The last torsion boxes I made were for A/V shelves. There were 18 of them, each was about 36" x 18" and had to be able to support amplifiers, vinyl albums, etc. without appreciable deflection.
Each shelf was supported by inserts threaded into the cabinet sides, so I figured minimizing the weight of the shelves themselves would ease the load on both the cabinet sides and inserts.
I cobbled together a support web of half-lapped 1/8"-thick ply on a diagonal grid about 2 or 3 inches across, bounded by 3/4"-thick mahogany, and skinned with mahogany-veneered door skins. I glued on the tops & bottom skin slightly oversize, and trimmed them for an exact fit with a router after the glue had cured. I measured the final thickness at about 1-1/2"
To glue them up I made a clamping caul out of 1X4s and 1/4" ply, and clamped the glue-ups to my workbench (topped with a protective sheet of melamine), with the clamping caul on top. The Titebond has held up well with nary a gap in several years.
Fully loaded with heavy power amplifiers and LPs, they haven't sagged in use, and weren't too heavy when it came time to move.
-Jazzdogg-
"Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie
I may be the only one who doesn't know this, but I'd sure like to see more on this. Thanks for the very interesting ideas... sure love it if you had pictures of any of this! :)
I've made torsion boxes in a variety of ways. My veneer press table is a 4'x8' torsion box, very flat and relatively light weight. Although I've never used it, the honey-comb material sold by Vacu-Press sounds like a great thing. I'm looking forward to a job where I can use it. The problem for me is Maine is a long way away, so shipping costs are prohibitive. Meanwhile, I'm experimenting using the blue Styrofoam insulation as a core. I've glued skins over this using urethane glue and so far the structure seems to be doing well. The solid core doesn't make for a true torsion box, but nevertheless seems to act enough like one to be useful. The plus side is it's quick to lay up and inexpensive.
Ive made doors that size in my kitchen for my pantry using MDF with glass inserts. There has been no problem with the weight on the hinges or with warping.
I've done this exact same thing using mdf. No problem as far as I'm concerned. Yes, they will be heavy, but I like the feel of a hefty door. Use at least four hinges if you're using the european type. You might also consider using Armor-ply. This is plywood with an mdf face on both sides.
MDF, or maybe very high quality ply will just fime for this application.
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