Glass shelves

[semenza]

    Thoughts on glass shelves? These will be inside a closed display case.  Approx. 26" x 30".  Planning supports at four corners plus back center and side center.  Tempered glass.

    Desiring to hold a minimum of 25 pounds. But more would be better to be on the safe side.

    Thickness?  Thinking 3/8" at this time.

    Would prefer just glass, but could probably frame each shelf with wood if needed.

Seth

 

[tjbnwi]

That dimension 3/8" tempered glass with 2' spacing on the supports will only support about 240 pounds.

If you're worried about that load go to 1 foot supports, about 4000 pounds.

Tom

 

[semenza]

That dimension 3/8" tempered glass with 2' spacing on the supports will only support about 240 pounds.

If you're worried about that load go to 1 foot supports, about 4000 pounds.

Tom

Yeah, I've looked at the load calculators, and I believe the numbers but they don't take support points into account. At least not the ones I've found.

If just doing the four corners is enough I would like to omit the center supports.

Also I am planning to use standards with individual supports not long brackets that span all the way across the shelf.

Seth

 

[tjbnwi]

I've used the numbers using just rubber coated shelf supports inserted into the 5 mm holes. Catching just the edge of a 3' span 3/8" thick tempered glass load rating is 360 pounds.

Tom

 

[semenza]

I've used the numbers using just rubber coated shelf supports inserted into the 5 mm holes. Catching just the edge of a 3' span 3/8" thick tempered glass load rating is 360 pounds.

Tom

    Yes, that is what I am planning for supports except probably using standards.  And thanks for the actual real use info. That is the type of thing I am after. Looking for some confirmation of the strength.

      I will have a wide (for glass) span in both directions which is why I am considering the center supports too.

      I have seen mention of glass shelves bowing under weight with out breaking  [eek] That seems like something to be avoided too.

Seth

 

[rst]

http://www.dullesglassandmirror.com/glass-shelf-weight-load-calculator.aspx

 

[Cheese]

FWIW Seth, you could go thinner if aesthetically, it bought you something. I have about 30# of crystal sitting on a 3/16" tempered 28" x 20" glass shelf supported on 2 sides in 2 places.

 

[semenza]

FWIW Seth, you could go thinner if aesthetically, it bought you something. I have about 30# of crystal sitting on a 3/16" tempered 28" x 20" glass shelf supported on 2 sides in 2 places.

OK, that helps. So sitting on four small points of contact?  I had originally figured 1/4" would be enough but figured a little more wouldn't hurt.

Seth

 

[Cheese]

I had originally figured 1/4" would be enough but figured a little more wouldn't hurt.

That's funny [big grin]...that's how we were encouraged to design capital equipment at 3M. Management's mantra was "steel is cheap, use as much as you want". From that comes my favorite expression, "Anything worth doing is worth overdoing". 

Here's a visual reference.

 

[leakyroof]

FWIW Seth, you could go thinner if aesthetically, it bought you something. I have about 30# of crystal sitting on a 3/16" tempered 28" x 20" glass shelf supported on 2 sides in 2 places.

OK, that helps. So sitting on four small points of contact?  I had originally figured 1/4" would be enough but figured a little more wouldn't hurt.

Seth

. My wife broke a 1/4" thick shelf in our Kitchen Cabinet , supported at only the ends on peg hole style supports. Span on that cabinet is 36" or slightly less. I changed all the 1/4" shelves over to 3/8" after that with better metal supports .
I vote for 3/8" shelves if your client stuffs cabinets like my wife... [eek] [embarassed] [embarassed]

 

[semenza]

FWIW Seth, you could go thinner if aesthetically, it bought you something. I have about 30# of crystal sitting on a 3/16" tempered 28" x 20" glass shelf supported on 2 sides in 2 places.

OK, that helps. So sitting on four small points of contact?  I had originally figured 1/4" would be enough but figured a little more wouldn't hurt.

Seth

. My wife broke a 1/4" thick shelf in our Kitchen Cabinet , supported at only the ends on peg hole style supports. Span on that cabinet is 36" or slightly less. I changed all the 1/4" shelves over to 3/8" after that with better metal supports .
I vote for 3/8" shelves if your client stuffs cabinets like my wife... [eek] [embarassed] [embarassed]

Was the 1/4" Tempered?

Seth

 

[rst]

Tempered glass is harder to break, it requires a sharp concentrated blow.  Years a go we used to pitch old tempered door glass down a stone side embankment and often it would clatter it's way to the bottom without breaking. That being said, automatic door operators used to be low pressure hydraulic.  The door had an arm on the pivot side that had a slot engaging a spindle on the piston.  Often these would be on the door for years and the arm would be difficult to come off the piston.  In practice I would lift the door and bump the out board end to pop the arm off.  I did this in a supermarket on a Friday late afternoon, the arm came off but the door glass popped, I and the entrance were promptly covered with small glass shards.  Ended up with small cuts and a mess keeping customers from leaving for about five minutes.  Worse part was having to drive an hour back to the shop and cut a piece of laminated and returning to install in the door.  Think I finished the door 10:30 ish and still had to drive home.  [crying]

 

[leakyroof]

FWIW Seth, you could go thinner if aesthetically, it bought you something. I have about 30# of crystal sitting on a 3/16" tempered 28" x 20" glass shelf supported on 2 sides in 2 places.

OK, that helps. So sitting on four small points of contact?  I had originally figured 1/4" would be enough but figured a little more wouldn't hurt.

Seth

. My wife broke a 1/4" thick shelf in our Kitchen Cabinet , supported at only the ends on peg hole style supports. Span on that cabinet is 36" or slightly less. I changed all the 1/4" shelves over to 3/8" after that with better metal supports .
I vote for 3/8" shelves if your client stuffs cabinets like my wife... [eek] [embarassed] [embarassed]

Was the 1/4" Tempered?

Seth

. Not sure.  The shelf broke neatly in the middle . No fragments that I remember, so maybe it was.... [huh]

 

[Cheese]

Not sure.  The shelf broke neatly in the middle . No fragments that I remember, so maybe it was.... [huh]

If it was tempered, it would have broken into thousands of small shards that tend not to have very sharp edges. If it broke neatly into several large pieces it was not tempered. Tempered glass is 4-5 times stronger than conventional glass, that's the reason you can get by with thinner glass shelves.

I gave my neighbor a 3' x 4' x 3/8" piece of tempered glass (originally an industrial awning) to place over his in-ground Koi pond. He used to use it as a bridge when he wanted to walk over the pond.  [eek]

 

[Tinker]

Way back before I was 39, I always wore safety glasses.  That was before I got rid of my cadilacs. If I was on my feet, I had my glasses hanging onto my face. One day I was playing with a couple of little kids at a friend's house.  They had a doll that the three of us were playing catch with.  All of a sudden, the doll colided with my glasses.  The lense disappeared into pieces the size of granules of sugar.  Most of the pieces ended up in my eye.  A short session under a water faucet removed all the debris from my eye and I told the kids I was a "one eyed sailor"  They had been real worried that I would lose my eye, but then i told them I was "a drunken one eyed sailor," they were right back to playing as before.  Before that little accident, I had not known how safety glass would disintegrate like that, but I sure was thankfull.
Tinker

 

[Daver]

Seth,

When you get to the build, I'd love it if you would post a couple of shots along with the dimension you decided to go with and bracket solution. I am probably going to build 2 glass-shelved cabinets this year and it would be nice to have more info on what worked well for your job.

Thanks,
Dave