Replies

1. 
   HowardAcheson | Jan 11, 2004 10:34pm | #1

   Go to a commercial glass supplier. They will answer all your questions. Be very careful, I have been involved with one lawsuit regarding a display case where the glass failed.

1. 
   mrearl | Jan 11, 2004 10:44pm | #2

   If "Tempered Glass" is used, what thickness? 

   There were some old messages the tempered glass is the best.

   Earl

1. 
   robkelly1 | Jan 12, 2004 01:01am | #5

   I built a display case that size and used 1/4" tempered glass bevelled 1-1/4" all around. The bevel gives a nice look, but almost doubles the price of the glass. The case has survived for 5 yrs so far, but it's in a private home, not a museum or shop where people lean on it.

2. 
   makita | Jan 12, 2004 02:17am | #8

     Mr.Earl,

           Although 3/16" tempered would be more than adequate for a36x24 top, for just a little more money, you could get nominal 1/4" [actually 6mm] and have a very substantial piece. If you decide to go with tempered, order it well before you need it, as only very large glass shops temper in house so there may be a significant lead time.

           chris

2. 
   Scrit | Jan 11, 2004 11:01pm | #3

   A safety alternative may be laminated glass which is available in thicknesses from 3mm (1/8in) upwards (you may need to check for safety codes on this). If you are allowed to use it it has the advantage that you can cut it to size - tempered (toughened) glass has to be cut to size before treatment, a job for the specialists.

   Scrit

1. 
   mrearl | Jan 12, 2004 01:46am | #6

   Thanks for the quick response.  The 1/8" laminated glass sounds best because it would be less weight.   I'll check on availability.  My glass dealer specializes in shower doors and other large applications but I wanted to be sure to know other alternatives. 

   'Enery the Eighth gave some good comments also.  I guess a glass that shatters into small pieces would be better than glass that breaks into large and sharp pieces.

   Earl

1. 
   Scrit | Jan 12, 2004 01:59am | #7

   My experience of laminated is that the Mylar layer in the midde means that it doesn't shatter at all, but you do have to check for codes. I've used it in shop display cases before now (6mm - 1/4in) because it more easily meets insurance requirements.

   Scrit

2. 
   JBD | Jan 12, 2004 05:55am | #9

   Hi Mr. Earl,

   I laminate glass for a living, and you don't want 1/8" laminated glass.  I assume you mean 1/8" total thickness cuz you mentioned less weight.  Laminated glass is not near as strong/break resistant as glass of identical thickness, because the thinner glass used in the sandwich can break at pressure points, like the its mounting locations.  Cutting it yourself is NOT easy - best done by a pro.  You are better off with ordering a pc of tempered in 3/16" or 1/4".  Very little difference as 3/16" is almost exaclty 3/16", but 1/4" is actually 1/32" thicker than 3/16" for some reason - not truly 1/4" - I have no idea why. 

   All my glass suppliers have very fast turnaraounds on simple sized tempered lites - like 2 days max, so order thru your local glass shop.  Tempered glass according to a custom template is ten times that long. 

   - JB   http://www.johnblazydesigns.com  

   "The furniture designer is an architect." - Maurice DuFrenes (French Art Deco furniture designer, contemporary of Ruhlmann)

   http://www.pbase.com/dr_dichro

3. 
   JohnWW | Jan 12, 2004 11:12pm | #10

   Laminated glass has an unattractive edge because you can see the plastic layer, it also has a problem with the plastic and glass separating inward for a fraction of an inch along the edge, the separation will be visible as a wavy line when looking through the glass.  For both of these reasons laminated glass is usually fully enclosed with a frame around its edges. 

   1/8 inch thick laminated glass would be way too thin for your application, I would use 1/4 inch thick for a good sized counter top, but my first choice would be 1/4 inch tempered because it is harder to break.

   Other things to consider:

   1.  Eventually the glass will need to be replaced, either because of breakage or because it will scratched up over time, try to design the piece to make replacement easy. 

   2. Glass is quite soft, it doesn't hold up well in high traffic areas such as a store counter near the cash register, where it will quickly become scratched badly.

   2.  The ammonia and other solvents in glass cleaners can soften and craze many wood finishes or stain lightly protected wood.  Glass cleaner and dirt will work their way around the edge of the glass, if it is in a rabbet rather than fully enclosed, the glass will have to be lifted out occasionally to clean out the visible grunge that builds up. 

   John W.  

   Edited 1/12/2004 3:38:00 PM ET by JohnW

3. 
   HenryVIII | Jan 12, 2004 12:15am | #4

   Actually, you want it to "shatter" if it fails.  If it breaks into large pieces, those are the ones that can either damage the stuff in the case or hurt someone.

   Tempered glass is made to either stay whole or shatter into pieces about as big as a grain of rice -- all at once.  But as a later poster points out, it must be cut to size first and then tempered.  Note also that whoever does the tempering is supposed to etch a little sign in one corner saying that it is tempered, and who did the tempering.

   Laminated glass is similar to auto glass, in that it is a sandwich of plastic between two pieces of glass.  It can be cut, and is designed to hold onto the large pieces when it breaks, rather than let them fall on someone/something.

   Annealed glass is the third type.  Most places it is illegal to have a window above a certain size or a glass door panel made of annealed glass.  Depends on the code where you live, but hereabouts, sidelights on doors have to be tempered if they are below 24 in. from ground level.

   Hope this helps