leveling glass

HELP!!!
Guy's I have been trying to get a piece of plate glass leveled to do some building on and it will not cooperate !!
It's a piece of glass used in a store front so it is safety glass.
It is sitting on a piece of counter top from Home Depot or abuilding center, and when I lay my straight edge on it and see the low spots, then use card stock th bring it up too level it will continue to show low in the same spot !!
Makes me wonder if the glass has a bow in it that will not lay flat ?
The glass is about 1/4" thick... Any help sure would be good...

What happens when you turn it over? do the low spots turn high? Glass is pretty stiff but is is really just a very thick liquid so it will flow although it would take years to show a measurable movement.

If the low spot turns high then it is the glass that is bent. If it remains low then the fault lies with what it is resting on, the straight edge, or the method you are using to check it.

Your glass is to thin, try at least 3/8" thick.

Not only is your glass thin but it is used. Your glass is no longer flat and will slowly take a new set as time goes by.

Thats why I spent $40.00 on a new piece whenI set my table up.

I think BIGS has the key - the glass is both thin AND old. I got a slab of ½" Plate from a mis-cut which cost only $45. It's 2' x 6' and I have no idea what it weighs, but I can't pick it up (maybe when I was 25 . . .)

This GLASS TABLE idea works great. However, nobody would tell where to get the glass magnets and glass pins. I just gave up and used a hot-melt glue gun.

Leveling the glass is no prob-lem!! Just use old issues of National Geographic. Quit kidding yourselves !!! A plain old storm window is plenty flat-enough to build a model airplane.

My new Stuntmaser is the flattest-ever.

I tend to think that the glass and shims are diflecting the door beneath...after enough shimming, that will stp...
You should be okay if you level the glass...and check it as you undertake new projects.
Have fun.

See Ya

Peabody, you are wrong on this one and Bigs is right. Chances are that glass is bowed and it is TOO THIN!