derimming a 20 long

[Hybridfish7]

Is it safe, and how should I do it properly?
I was thinking I'd just be able to reseal it and get a glass brace on it and it should be fine, but you tell me
I just tried derimming one of my empty 20 longs from the last DPG sale and it cracked because I rushed trying to pull off the top rim. Bottom rim came off pretty quick and easy. I think I'll try sawing the corners of the top rim first next time, if there is a next time.

 

[Hybridfish7]

Nevermind I figured out how to fix this, I can just take the tank apart, cut the glass to the lowest point of the crack and put the rest back together
And maybe save some of the glass for bracing
Only thing I haven't figured out with rimless tanks is keeping the fish from jumping out