Glass doors on Library shelves -HELP PLEASE

[Thomas Canfield]

I have been asked to volunteer to put some glass doors on a section of built-in library shelves that can be locked to keep some of the more valuable books secure. The current shelves are built with 3/4" plywood frame with 1 1/4" x 3/4" Ash trim nailed to plywood and peg supports for shelves, and have opening of about 83" high x 33" wide. The original thoughts are making 2 doors that would be 83" high x 17" wide using 2" x 3/4" ash vertical and 3" x 3/4" top, middle, and bottom frame and then have 2 glass panes per door that would set in rabbet on back side and held in place by 1/8" or 3/16" strips screwed to back. Each door would be hinged on 4 surface mount hinge so that the door would overlap the existing trim by 1/2", and the surface hinge would allow hiding a long screw to better attach the 1" wide trim to the plywood frame. All the existing shelves are adjustable, but plan is to fix the one in middle to help lock doors.

Comments on above design, or would 2 full width doors, about 34" wide by 42+/- high be better? I think the concept of surface mount hinges and hiding strength screws will be required to make a stable mounting surface.

[Charles Wiggins]

Given what you've described, I would go with the two side-by-side, full-height doors. The wider doors would be more prone to sagging or racking and would require a lot of swing clearance to open.

[Sam Murdoch]

I agree with Charles and your first instinct that 2 doors will be better than one - in all respects. From a design standpoint I think that a door that tall would be better with 2-3/4" to 3-1/4" wide stiles, 7/8" thick would be better than 3/4" (might mess up your hinge plans). Also I would make the top and middle rail match the stile dimensions but would be inclined to add an 1" or 2" to the height of the bottom rail. These are all considerations that would improve the look as well as add some racking strength to the doors supporting those pieces of glass. Another idea would be to lower the fixed "middle" shelf so that it visually favors the bottom of the cabinet. The top glass section would be taller than the bottom - maybe enough just to have the top of the mid rail be below center.
Great idea to fix at least that one shelf.

All these suggestions to be considered knowing that I only have a description of the cabinet. A photo might lead me to other conclusions. I am just responding to the described size of your unit.

Two more thoughts:

1) The surface mount screws will kind of defeat the idea of securing valuable books.

2) I hope that the ash face frame is also glued to the plywood sides. Otherwise, yes, do add screws where you can at each hinge location. Those might be essential.

Regards, Sam

[Thomas Canfield]

Thanks Sam - those are good suggestions and what I was hoping to get. It is hoped that the ash material can be obtained through a local cabinet shop and thicker than 3/4" obtained. Semi-concealed hinges will allow a lip to cover the cabinet frame face and work with thicker material. I am almost certain that the ash face strip over the plywood is only nailed and will look to add some #8 or 10 x 3" FH screws under the hinges.

Concerning the surface mount hinges, the screws could be removed, but then this is a church and a lock only keeps an honest man honest. The main thought is to limit handling and provide some appearance of security.

Any suggestions for glass about 36" x 14"? It will be special in any case, and tempered might be prudent?

[Sam Murdoch]

Public space glass should be tempered glass.

The thickness of the undimensioned lumber should be no less than 5/4 in order to be able to joint it flat to a 7/8" to 3/4" thickness. Don't skimp here in order to save a few bucks. Doors of this size (height especially) will only be successful if you have truly straight - in all dimensions - stiles. Rails too, of course, but not so critical in that width. Yuo need to start thick enough to be able to joint and then thickness plane to flatness. You cannot depend on buying predimensioned lumber. Sorry if you know all this. Just being cautious for you.

Sam

[Thomas Canfield]

Sam, Thanks again. I agree with all you said. I am presently without a jointer so will have to work around that problem and get that step done somewhere. Planning for something like this really pays off in avoiding problems later. I have been checking out hinges and locks and will get a better feel for what the "committee" wants and then make final plans.

[Sam Murdoch]

Hi Thomas - there have been quite a few recent threads on this forum about how to make up a sled that rides through the thickness planer for straightening stock when you don't have a jointer. You can search to find those threads but at least one led me to see this:http://www.finewoodworking.com/skillsandtechniques/skillsandtechniquesarticle.aspx?id=5245.

Interesting, though I am quite fond of my jointer.