Replies

1. 
   mikegagne | Jul 07, 2005 08:12am | #1

   Redhen, your glazer knows best. My guess is thats a little wide as you dont know the weight of the knick knacks. Tempered is stronger but has a moment where it will let go suddenly with a load or when struck on the edge. 3/8 or 1/2 inch is probaly overkill but will certainly do the job. I would guess at that size its not too expensive but be sure to figure in the edge seaming or whatever treatment it needs. Aloha, mike

2. 
   dondownunder | Jul 07, 2005 09:16am | #2

   Redhen

   When I need the same info I call my glass wholesaler & ask. I assume they have a reference because the replies are pretty consistent.

   I think you may find laminated a better option than toughened, however I have only ever fitted plate based on the glass company's advice. You will also likey find that polishing edges will add substantially to the price so get that factored in too.

   Don

3. 
   Steinmetz | Jul 07, 2005 12:25pm | #3

   Red, Plan on either a small triangular or 1/4round'ledger board' to support the back edge of the glass between the end supports.
   Or,just a tiny clear plastic support at the center?
   Steinmetz

4. 
   papanick | Jul 07, 2005 04:43pm | #4

   You can span that okay with 3/8 glass. not 1/4.

   I just went though this whole thing a month ago when my detailer drew 48" shelves on my project. I made an ugly Excel sheet that calculates sag. I deal a lot with glass components, so I have a bit of experience.

   You have to detemine the load/inch including weight of glass, the span, width, modulus of elasticity of the material, etc.

   Bottom line, tempered is the way to go, since the surface stresses hold the glass more rigid. Also it is safer, since it cubes when it breaks. Laminated glass can still fragment, depending on the film they used, and how old it is. It's also the same price.

   You can only have max 0.4% deflection of the glass. With 1/4" glass, you'll have .32" deflection (0.94%); with 3/8" glass you only have 0.09" (0.28%)

   3/8 tempered glass costs about CDN$9-10/sqft, weighs about 5lbs/sqft, and would only need one long edge "polished" other edges "arrissed".

   Expect a week for frabrication in most cases, and BE EXACT ABOUT YOUR SIZES WHEN YOU ORDER. Tempered glass is inviolate once it comes out of the kiln. no drilling, cutting, nothing.

    

   The older I get, the better I was....

1. 
   jackplane | Jul 08, 2005 08:19pm | #7

   good info,thanks for posting. 

5. 
   sharpblade | Jul 08, 2005 12:41am | #5

   A similar question was posed on Breaktime, about a month ago, depth was 5 in instead of 4. It wasn't you, now was it? You may want to do a search there, a lot of info was shared by all.

6. 
   eddiefromaustralia | Jul 08, 2005 02:00am | #6

   I have an old table giving safe loads scanned and saved somewhere.  If I find it I'll post it later.

   A google search brought up the following useful links:

   http://www.aaamsa.com/Documents/ Selection%20Guide%20for%20Glass%20in%20Furniture%20New.doc

   http://www.nationalglass.com.au/products/pdf/11.pdf

   http://www.pilkington.com/resources/glassandsafety.pdf

   Cheers,

   eddie

   Edit:  I do the same as Don - if I need glass, I tell my supplier the application and let them suggest what's appropriate.

    

    

    

   
   

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   Edited 7/7/2005 7:14 pm ET by eddie (aust)