Heavy Institutional Cabinet Doors
Considering the materials and hinging options for large replacement doors on hospital cabinets. January 20, 2007
A local hospital wants me to build replacement doors for built-in wardrobes in their patient rooms. The doors that are there now are MDF with melamine on one side and vertical grade HPL on the front and edgebanding. They're 23"w x 78"h and heavy. They were originally installed with three no-name brand euro hinges. These hinges failed repeatedly. The hospital maintenance crews will do all the installs. I will just build the doors. They want something lighter if possible.
We discussed possibly building these doors out of a high quality pre-finished plywood product like NOVA. I showed them a sample, which they liked. What do you think? Is that a good alternative to the MDF? How about warping in a situation like that? With a door that big, how many hinges would you use?
Also, I discussed the infection control aspect with them. I thought non-pourous HPL was required. The hospital says not and that the coated plywood will be fine.
From contributor T:
Hafele sells a door straightening gizmo that inlays into the back of the door. It's essentially an all-thread rod that connects to a bolt at each end. As you tighten (or loosen) the bolts, the door is pushed or pulled back to flat. Given the size of these doors, and the experience your customer has already had, this solution should be an easy sell. It will certainly increase the range of possible materials that are viable.
From contributor A:
That size door is a 4 or 5 hinge door with the width. Most Euro type hinges need to be tightened with a pozi drive bit. If the maintenance people are using Philips, they will have problems. Euro hinges are Grade II and most hospital work uses Grade I. A 120 degree hinge would wear better than a 170, but it is more susceptible to breaking if it is swung open too far. We use MDF or IPB core all the time with doors that size without any trouble. The doors also really should be balanced (laminate both sides).
From contributor B:
Forget Euro hinges. They'll fail eventually on this stuff. Use institutional hinges with hospital tips. They don't call 'em that for nothin'! You could use ultralight MDF to reduce the weight, but the screw holding power is even worse than regular MDF. I don't see plywood as an option - you can't expect it to be flat enough. Were it me, it would be Skyblend particleboard, laminate on two sides as contributor A says (laid up by someone with a press), 3mm PVC or ABS edgeband with 3mm radius, probably 4 institutional hinges per door.
From the original questioner:
I've never used institutional hinges, but I found many pictures on the web. Those would work well, however, they also look like they would be hard to install given the weight of an MDF door. Ah, just remembered, I don't have to install them :-). I've pretty much talked myself out of the plywood idea. The folks at States Industries who make NOVA said it would warp.
From contributor K:
To start off with, 3 hinges in a 78"h door is the beginning of the problem. As contributor A said, that door should have 4-5 hinges. 5, in my opinion. I agree with others that the hinge screws and MDF tend to be problematic. For this setting, you could use the pre-finished ply with a PVC edge. If the ply is not an option, when forced to work with MDF, glue in wood inserts (dowels, plugs) into where the screws for the hinge are and the screw will last much longer. Also, always try to use a hinge plate that uses 2 screws instead of one.
By the way, if any of the hinges fail in the future, as unlikely as that may be (they will most likely replace the actual cabinet by this time), unlike MDF, you can repeat the plug process over and over again without replacing the door. Have to check into that Hafele product contributor T mentioned, though... Sounds interesting.
From contributor S:
I don't build commercial/institutional, but I would do this. Ultralight MDF laminated 2 sides with 5 hinges. Only thing would be to mount 2 hinges right next to each other on top and bottom. All the weight is on the leverage points, which would be the top and bottom. Middle hinges are more for guiding and don't have as much weight leveraged against them. We have done this before on large wood doors or doors with large glass panels. In all reality, for what the cost of a hinge is, why not do 3 top and bottom each and one in middle? That is a pretty big door with heavy usage.
From contributor B:
The institutional hinges are actually very easy to install. After you do a few doors, they're almost as simple as euro hinges. All of them have a few screw holes elongated so you can adjust the door if necessary. Just install those before drilling for the holes for the other screws. Also, Hafele makes one - I think it's called the Advantage 5K (p. 555 of the new catalog) - that is set up so you can put a screw in your system holes in the carcass, then slide the hinge over it. No need to try to hold the door in place while you try to get a screw or two in. Makes hanging the door very easy. Then adjust and set the screws. These hinges require different reveals and such than Euro hinges, but this is what they were made for, and the weight will be no problem at all for them.
From contributor L:
Whoever made the original doors had no clue! Unbalanced construction, wrong hinges (won't pass any hospital grade requirements), too few hinges. Easy fix: balanced construction (same lam 2 sides, same direction of grain), institutional hinges, correct number. I've never seen plywood that will stay flat, especially at that size. You may get some resistance from decorator types, since institutional hinges have a small hinge pin area that shows. Institutional hinges will also have a wide swing without the limits of typical Euro hinges.
From contributor C:
Trupan Ultralight MDF is the way to go. 1/2 the weight, only a small premium on the price. Definitely laminate both sides after the edging. This is a good money maker. I hope the hospital is huge.
From contributor E:
PVC board. Great stuff. Cheap, light, won't warp or expand. Canít burn and it takes well to contact cement and even edge banding, so it can be laminated and banded just like the MDF. Messy to cut, though. Seriously, you land lubbers need to start looking into the stuff we are using on boats already.
From the original questioner:
I wanted to get back with you about how this went. I ended up using MDF laminated with HPL on both sides and edgebanded. I used four institutional hinges and bolted them through the door with 1/4" machine screws and lock nuts. Maybe a bit overkill, but a full length jig made it quick and easy. The hospital administrator and the maintenance guys loved them. They called today and ordered 40 more.