Set of drawings for a home we are doing from the architect and they have several banks of adjustable shelving in the living areas. These all have interior lighting, pre-wired (by us), in the cabs. The architect is wanting to use tempered in the units to allow the lighting to flood the interior of the space but they are wood faceframe units. They are thinking about applying 3/4" thick x 1 1/2" tall edge band to the glass just as you would to a ply shelf. I havent gotten clarification if this would be via rabbet or dado (lip on the front of the shelf). The edge band would run between the stiles (not completely out to the edge of the glass shelves that project past the stiles). We even kicked around the idea of a slip on option with a rubber weather strip channel but that would never work.

I understand what they are trying to do by hiding the edge of the glass shelf and keeping the unit looking like a conventional wood shelf unit with a transparent shelf.

I floated the idea of a ply shelf with a rabbeted pocket CNC'd for a glass panel to drop in but didnt fly and I could see a ton of flaws in that as well.

We will of course disclaim any option we cant be comfortable with.

I dont see issues with wood movement with a small wood applied face to a glass shelf but I somehow do fear a bit of deflection in a loaded glass shelf overcoming the bond bewteen the glass and the wood (clear RTV?).

Google left me hanging.

Any ideas?

I would put a 1/4 x 5/8 deep dado (you will need to leave a lip sticking above the surface of the glass), and put some silicon in the groove, then push the glass into it.

I wouldn't think deflection would be a problem with the bond as long as the length of the shelves is kept at a reasonable length.

I've done a lot of shelves with 3/4" x 1 1/2" frame all around the glass. The 1 1/2" is the vertical dimension. With the rabbet, there is only 3/8" of wood extending past the glass. You could make the frame a little less and still get a good result. I suggest you make them a couple samples to show there is no light transmission issues through the shelves.

I have never done this, so I do not have a reference for you. However, something I did learn this last year is that when glass is tempered, it warps, and they have no control on how it will warp. That might present a problem. I don't think you have to have tempered for shelves. This is probably a safety precaution.

Silicone is probably your only choice for attaching the wood edge. Silicone is an adhesive. The Crystal Cathedral in southern California, built in the 80's is built with silicone. Some believe silicone is only a sealant, it is also an adhesive.

Thanks guys,
The dado/silicone was my thought but I am going to guess they will want no lip at the edge of the shelf so the rabbet would likely be the option. I wasnt sure if we could trust silicone over the long haul in that situation but it sounds like its worth a go.

Paul, we have seen the warp in tempered. We just brought in a crate of tempered for a job and didnt notice much but it was all for interior window units so any warp was dealt with in the stops.

Our local glass shop never uses tempered for shelves but it seems to always be spec'd as tempered. I do feel much more comfortable with the tempered even just around the shop. In my own house we recently had a large 3/8" thick plate coffee table top that broke and its a wonder someone wasnt cut to ribbons.

We will go the sample route with the dado and the rabbet with disclaimer and see what they choose.

try a PUR adhesive, check with 3M.

You could use a compromise between standard glass and tempered. That is laminated glass. Just like a car windshield. I will crack, but not separated from the film in the center. Only downside is the edge always shows the lamination. Not a big deal when it has a wood edge glued on.

I think the real issue is I would want a square edge to glue to and as a practice the last thing we want to handle is glass without polished or swiped edges.

I think the lack of a square edge to glue to will cause issues we haven't even discussed..

Tempered glass is not only a lot safer, it will carry something like 8X the load of untempered glass. I would want to use a dado, as Jon described. A rabbet relies too much on the glue bond. I made the glass doors in the attached photo, including the curved glass panels. The glass is glued with polyurethane adhesive into dados in the door frame stiles and mid rails. Note, there is no perimeter frame. The adhesive holds the glass. 15 years or so now, no creep, and no problems.

John

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I dont see issues with wood movement with a small wood applied face to a glass shelf but I somehow do fear a bit of deflection in a loaded glass shelf overcoming the bond bewteen the glass and the wood.