drilling a tank?

[johno4]

If the tank already has holes drilled, isnt it safe to assume that at least that peice of glass is not tampered? I have a 135 that has two holes drilled in the back panel. I need more these holes are for 1/2 in bulkheads and I obviously need more larger holes. I bought the tank used with the holes already in it. Since there is already holes drilled I am going to assume that I can drill more holes in the same panel of glass. Is this wrong?

 

[LazyD]

Yes, or at least in some cases it is wrong. Many companies, especially when were talking about the bottom pane of glass drill the holes before they run it through the tempering process. Because were talking about the back pane of glass it is more manufacturer specific.

 

[johno4]

So your telling me that a company would drill only 2, 1/2 in bulkheads in a back pane of glass?

 

[hllywd]

Depends what the customer ordered....

Use a couple of polarizing lenses one on each side of the glass to look for stress patterns that develop during the tempering process to decide for sure. You can test the method on the side window of a car (or other known tempered glass) to see what I'm talking about.

Tim

 

[tptp279]

if you bought it used, ask the person you previously both it from if he personally drilled it. if not, look for the manufacturer and call them.

 

[johno4]

there are no marks indicating whether its tempered or not, not manufacuturer and I cant call the pereson I bought if form b/c I have no clue who I bought it from, it was about 5 years ago out of the new paper.

 

[hllywd]

The physics lab where you teach should have the polarizing lenses...