Keeping a glass-front door from sagging

[Josko Catipovic]

I'm making 32"x48" glass-front doors for display cabinets. Esthetically, I'd like rails and stiles as narrow as possible, but am worried about the door sagging (pulled into a parallelogram shape) over time and eventually binding on the bottom of the case. Door frame is cherry, ~3/4" thick. I'm thinking of mortise and tenon, but am wondering if laminating out of 1/4" stock would produce stronger corner joints. Glass is likely 1/8", one large pane. Are there guidelines for min. rail/stile dimensions given door size? Diagonal stiffeners are not an option. Any advice or experience would be welcome, and thanks in advance.

[Jamie Buxton]

If you fit the pane tightly in the frame, it will act as a diagonal brace.

With narrow stiles, put the hinges near the top and bottom of the door. If they’re near the middle of the door, the weight of the door will bend the hinge-side stile.

[Lee Schierer]

For doors that large you might want to think about tempered glass for safety reason.

[Mel Fulks]

For doors that large you might want to think about tempered glass for safety reason.

Yeah , the law takes that stuff seriously. Liability stays with home owner who cheaped out after he has moved out.

[Wayne Lomman]

C
Based on experience, consider making the door lift up rather than swing from the side. Gravity always wins in the end. A good mortise and tenon joint will work. There is no set rule as to size but you can calculate the engineering required to do the job if you are so inclined. Another option is to use polycarbonate sheet rather than glass. Its light and will keep the liability issues away but is a bit more delicate to clean without scratching.

Mel, are you serious that you can get sued for stuff like this after you have sold your house? Here it is caveat emptor. Cheers

[Paul Girouard]

I'm making 32"x48" glass-front doors for display cabinets. Esthetically, I'd like rails and stiles as narrow as possible, but am worried about the door sagging (pulled into a parallelogram shape) over time and eventually binding on the bottom of the case. Door frame is cherry, ~3/4" thick. I'm thinking of mortise and tenon, but am wondering if laminating out of 1/4" stock would produce stronger corner joints. Glass is likely 1/8", one large pane. Are there guidelines for min. rail/stile dimensions given door size? Diagonal stiffeners are not an option. Any advice or experience would be welcome, and thanks in advance.

I’d suggest beefing up to 13/16 “ or 7/8” for thickness.

I’d use Blum hinges , and I’d make the styles 2 1/2” wide. The rails could match , or a nice look on cabinet doors is the bottom rail being wider say 3” or even 3 1/4”.

To further strengthen the door frame I’d glue the glass in with clear silicone.

Generally cabinet door glass isn’t required to be tempered , but this is a good sized piece , so having it tempered if it’s in a high traffic location.

[Josko Catipovic]

Thank you, all. We ARE using low-reflectivity laminated glass, as the cabinets are for displaying historic artifacts. They'll be opened rarely, but it would be bad form to have the doors sag. I like the idea of gluing in the glass - is there something that would creep less than I'd expect silicone sealant to, and still allow glass removal in case of breakage?

[Mark Bolton]

We set our glass with RTV. I would agree with Paul that a bit thicker would be nice but perhaps not essential. Laminated is fine for safety. I personally wouldnt have any problem making the rails and stiles as narrow as you'd like and as mentioned just fit the glass tightly into the door and bed it in with RTV or silicone. The main issue you will find the narrower you go will be that the door may be a bit be wobbly in use but as you mention its a display case and if its rarely opened it shouldnt matter. If you really dont trust the silicone incorporate a rabbet on the back edge of the door that gives the door support from the frame/opening when closed but I wouldnt be concerned with it.

[Tom Bender]

Inset some steel on the inside. 1/4" x 1 1/4" across the bottom and up the hinge side, mitered and welded at the corner should be plenty strong. Drill and tap for hinge screws.

[Mark Bolton]

Inset some steel on the inside. 1/4" x 1 1/4" across the bottom and up the hinge side, mitered and welded at the corner should be plenty strong. Drill and tap for hinge screws.

Gadzukes. Better be a high dollar project. Steel may introduce more weight than it supports lol. We just pulled out a bunch of small window sash that someone tried to "beef up" with this technique. I wish it'd have worked because we wouldnt be pulling them out.

[Gene Davis]

The glass exteriors of highrise buildings are glued on with structural silicone. Use ordinary silicone adhesive, it does not take much, to glue the glass to your frame. You'll have no sagging if you use adequate hinges.