# Changing Broken Panes



## bunafireman825 (Dec 7, 2014)

I have a 125 gallon aquarium that I loaned out and it was returned with a broken bottom glass. The good people used it for a snake cage and placed the heating rock directly on the bottom pane, FYI glass and heat are not a good combination. Since I have a few years background in the glass industry I've decided to take on changing the pane myself.

*Getting started-Removing the trim.*
*Tools Used-Putty Knife, Long BladeRazor*










Start with removing the silicon inside the tank that sills the bottom to the slides, cut along the bottom then the sides to remove the wedge of silicon. This is best done before flipping the tank to start the trim, it keeps from having to flip the tank multiple times. I had already removed the silicon before snapping the picture.










With assistance of a friend i flipped the tank over to start removing the trim.

Start with finding a place to insert the putty knife to hold the trim up so the razor knife can be inserted. Begin cutting the silicon and moving the putty knife behind the razor to keep the trim up. 

The edges were siliconed firmly down and i couldn't insert the razor knife there. The trim going across the middle wasn't siliconed down making the putty knife easy to insert there. 










The trim should lift easily after all the silicon is cut, I had to slide the putty knife in between the side glass and the trim to cut the silicon that went up the side in the corners.










*Removing the glass*

*NOTE: Kevlar or other cut resistance gloves should be used when handling sharp glass.*

A good look at why the glass needs changing.










Here comes the tricky part, getting the glass to lift off the sides without breaking or oystering the sides. I found a spot next to the crack where I found start cutting the silicon between the panes. Then carefully preyed the glass up with the putty knife to open it up so the silicon could be cut deeper. Cutting pressure should be applied to the broken pane to avoid damage to the other panes.










A glass cutter may be necessary to finish removing the glass, these can be bought from most hardware stores for around $5. Make sure the glass is clean where you plan to cut, dirt and grim and cause the cutter to skip. Using a straight edge that the cutter can slide down score the glass from one end to the other. Then a tap from the other side if the glass from the score with a hammer will get the glass to break on the score and follow the score. Then a score from the corners to the lengthwise cut will help the corner pieces lift. Continue removing like the previous pieces.










The glass removed.










That's as far as I made it today and will order the glass Friday. The sides of the 125 gallon are made of 3/8" and the bottom is 1/2" so that'll raise the price a bit. Depending on that factor will decide if I continue this project or buy another tank.


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## discusbreeder (Oct 7, 2014)

To prevent the sides from oystering make a snug fitting wooden frame and screw it around tank before you remove bottom. two diagonal braces inside the tank will also prove useful in maintaining rigidity and squareness. The other big tip that most people do not know is spacers. If you check closely in the ends of the removed silicone you will find paper spacers. These spacers are required to keep silicone in the joint so that you get a good seal. they are just small pieces of thin posterboard.


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