I have used super glue on many different occasions on a few of my tanks and it appears to be non-toxic as far as the fishes' health is concerned. However, as far as the structural ability goes, I am not sure it could withstand the seperation force of a top brace...
true original super glue yes it will hold and then some. Most super glues today are not the original formula. the original formula can hold i believe it is 1000 pounds per square inch of glue. fish safe i dunno but if u can get a good glue and a good bond then it will more than hold
I originally wanted to use this method, but i can't drill into the bracing without risk breaking it off completely because obviously I'd have to push down on the brace with the drill and the plastic brace will likely just snap off.
I ended up going to Lowes and picked up this super bonding solvent that bonds all plastics.
I used super glue to repair a crack in the housing of my AquaClear 110. Worked fine and no fished died.
Do you still have the (broken) center brace connected to the tank?
I've repaired 2 broken center braces by using a piece of acrylic to fix it. I cut a sheet of acrylic (about a 8 inches wide, 1/4 inch thick) to the width of the tank (can buy at Home Depot). I drill holes in the center brace (or if you have enough room, you can drill the holes in the top bracing). Drill holes in center brace and acrylic sheet (you can use small or large holes) and line em up. Use stainless steel bolts or galvanized bolts to adhere the two pieces together.
My 60 gallon was fixed 2 years ago and is going strong. You say you can't use a drill because you'd have to push down. Not True! If you have a good drill bit and a good drill, you shouldn't have to add any pressure at all (let the machine do the work!!!!).