Tempered or Not???

[Ratkiller]

Is there a way to tell if a tank has tempered glass?

I picked up a used 90gal over the weekend and want to drill it for an overflow. Weither it's drilling the back, bottom, or side I don't care. I just don't want this thing to shatter. Any help would be appreciated.

[james3370]

bright light source (sun, laptop w/ white page on screen) shining thru pane of glass you are checking + polarized sunglasses from wal-mart etc is the easiest way to tell.

look at the side/rear windows of your car in the sun & thru the polarized sunglasses you will see kinda a "waffle" pattern....that is what you are looking for on the tank panes. if you see that it IS TEMPERED & can't be drilled

[TheH]

You can also contact the manufacturer.

[seashark]

^^^ +1 i would contact the manufactorer

[newbuthandy]

+1 on the polarized sunlasses. It works fine

[Ratkiller]

There is no markings as to who the manufacture is. I tried the polarized sunglasses technique and didn't notice anything change in the effects on the glass. I know what you mean about the "waffleing" patteren but I didn't see anything not even on the bottom. I would think on a 90gal with 3/8in think glass, at least the bottom would be tempered. Or am I wrong?

[reefman5511]

Most tank bottoms are tempered. Side panels are another thing. If you go the websites of the various manufacturers you should find a page that gives dimesnions & whether tempered or not.

[james3370]

There is no markings as to who the manufacture is. I tried the polarized sunglasses technique and didn't notice anything change in the effects on the glass. I know what you mean about the "waffleing" patteren but I didn't see anything not even on the bottom. I would think on a 90gal with 3/8in think glass, at least the bottom would be tempered. Or am I wrong?

not necessarily.....3/8 is what the garf site recommends for a 48x18x24 tank (w/ eurobracing) so 3/8 would be in spec for that size. typically, manufacturers will temper it if they make it out of thinner material (since thinner is lighter & lighter=cheaper shipping...especially true of "wal-mart" 55 tanks)

since it isn't thinner than recommended for those dimensions, it might all be untempered....they might have saved the price of tempering the glass

[uncleof6]

not necessarily.....3/8 is what the garf site recommends for a 48x18x24 tank (w/ eurobracing) so 3/8 would be in spec for that size. typically, manufacturers will temper it if they make it out of thinner material (since thinner is lighter & lighter=cheaper shipping...especially true of "wal-mart" 55 tanks)

since it isn't thinner than recommended for those dimensions, it might all be untempered....they might have saved the price of tempering the glass

http://www.freesmileys.org/smileys/smiley-fc/popcorn.gif (http://www.freesmileys.org/smileys.php)

[uncleof6]

:lol:

12mm with euro for that size tank (safety factor 3.8), I like GARF for many reasons, but on this stuff I believe they are out of their tree. Do not take anyone's word or assumptions on whether or not a tank is tempered. That is a whole lot of glass to clean up if it is. Even talking to the manufacturer is not 100% certain, just saw a thread on that, unless I am batty (may be.) Some glass shops do have the equipment to determine whether a sheet of glass is tempered or not, and this equipment does use polarized light.

Along with the sunglasses thing, another one is the LED screen/glass/polarizing camera filter.

Jim

[BeanAnimal]

GARF... I almost forgot about them... yeah some of their recommendations are far from realistic though the website has a lot of good information if you can find it in the quagmire of broken links, widgets and poorly written code.

Now that I think about it, that site is one of the biggest disasters I think I have ever had the pleasure of browsing... to think this is the NEW version. I have blocked the old site out of my memory it was so bad. If I remember it was pink and blue and looked looked like it was barfed out of FrontPage.

Anyway... the sunglasses trick work fairly well. If you are still not sure, for a 90.... I may just try and if it pops... ohh well :)

[uncleof6]

GARF... I almost forgot about them... yeah some of their recommendations are far from realistic though the website has a lot of good information if you can find it in the quagmire of broken links, widgets and poorly written code.

Now that I think about it, that site is one of the biggest disasters I think I have ever had the pleasure of browsing... to think this is the NEW version. I have blocked the old site out of my memory it was so bad. If I remember it was pink and blue and looked looked like it was barfed out of FrontPage.

Anyway... the sunglasses trick work fairly well. If you are still not sure, for a 90.... I may just try and if it pops... ohh well :)

IIRC, the new website was done gratis, I may be wrong. You get what you pay for. A good website can be upwards of 5 grand (not in ALL cases.)

I have web developer tools in my browser, and I can tell at a glance why a website is lagging, or not quite working right. GARF's home page is invalid HTML 4.01 Transitional, with 57 errors, and 9 warnings, and runs browsers in quirks mode.

RC's home page is invalid XHTML 1.0 Transitional, with 79 errors, and 11 warnings. However it runs the browsers in standards compliance mode. (Very common for xhtml code, if the mime type is incorrect, and the code does not include a special check, and the user agent sends the mime type in the page's header to the W3C validator. (text/html in this case, rather than xhtml's mime type which is application/xhtml + xml)

This is done (incorrect mime type in header) because the most popular browser is the least intelligent, and presents xhtml documents as tag soup.

OH dang...... yeah I agree if it shatters it's tempered....

Jim

[newbuthandy]

Did you look at your car windows? If you saw the pattern then you know your glasses are polarized. So if you didn't see the waffle on your tank it is not tempered. It is that simple. Drill it. Put it on film though, just in case. Then you can show the rest of us

[james3370]

Did you look at your car windows? If you saw the pattern then you know your glasses are polarized. So if you didn't see the waffle on your tank it is not tempered. It is that simple. Drill it. Put it on film though, just in case. Then you can show the rest of us

my point exactly for saying to look at the car window first

1) to know what to look for
2) to make sure your glasses are indeed polarized

....so if ya see it in the car windows (which you know are tempered) & not in the tank, then the tank isn't tempered & drill to your heart's content
:bounce3:

[BeanAnimal]

IIRC, the new website was done gratis, I may be wrong. You get what you pay for. A good website can be upwards of 5 grand (not in ALL cases.) In some ways yes... in some no. A bad website is a bad website, free or not :) The GARF website has been a disaster since its inception...

The problem is not speed or XHTML validation errors... the layout and organization and intersite links are a mess and the CSS theme is broken. It is better than last time around but it still...

As for XHTML validation... BeanAnimal.com is valid XHTML TRANSITIONAL on all pages but one with an embedded flash script. (as are most of teh sites I develop) The site would pass as STRICT, but I have external links open in a NEW window use rel="_blank" and that is not allowed in STRICT and refuse to change it just to pass as STRICT.

As for tempered glass and polarized glass....

Guys you need to be careful, sometimes the effect is very hard to see and depends on the light and angle you are viewing from.

[DaveBien]

In general, and I stress IN GENERAL, the best way to use polarization, ie: the glasses, is in increments of 90 degrees. In this case look at the tank straight on then rotate the GLASSES 90 degrees and look thru. Continue to rotate thru 360 degrees while looking thru the glasses' lens. This is the way polarized lenes word on a camera.

PS: The car window trick works pretty good too !!! LOL

[Ratkiller]

My sunglasses are polarized and I do see the patterens in car windows but nothing in the tank. I looked at all different angles still nothing. I'll be draining it this weekend but before I drill I'll do a close inspection at multipule angles again just to make sure.

[james3370]

i would also take it outside in the bright sun so you have light coming at it from alot of angles to make sure you aren't missing the tempering "pattern"

[Mike31154]

Make sure you have a notebook computer with LCD screen and white screen on the other side of the glass when you're looking through it. When I checked the tank I drilled last summer, I knew the bottom was tempered since it was marked as such. So when I checked the side I wanted to drill, I made sure I knew what I was looking for by first looking through the bottom pane at a white screen on my notebook while wearing the polarized glasses. I had to tilt my head 90 degrees or maybe more to see the pattern. It was not a waffle pattern as seen in car windows, but horizontal black lines. The reason for using a notebook computer or other LCD screen is because virtually all of them also have a polarized filter over them to reduce glare when in bright conditions or sunlight. Even your cell phone LCD screen should work. Just get a white screen on there to make the pattern easier to discern. The key to this is two polarizing filters, the glasses being one and the LCD screen the other.