I have been looking all over the net to try and find if anyone has turned a regular tank into a rimless. Well just the top rim anyway. I have several 20g high tanks and I am going to take the upper rim off very carefully. What do ya guys think? I dont think it would hurt the structural integrity to much. Or do you think other wise??
Yes this can and has been done. I did a 20gal high a while ago. I suggest lots of fresh razor blades to get all the silicon scum off. The top edge of the glass may be somewhat jagged so I suggest using a whetstone to smooth it out.
you do need to be careful that the top of the tank does not bow out when filled. the black rim acts as a support to prevent this from happening. if the tank is over 19" tall, you could have issues depending on how thick the glass is.
I asked my statics professor today after class and the actual pressure at the top of the tank is not relevant to the mid to lower part of the tank. Meaning that the weight of the water at the top of the tank is nowhere near the pressure at the bottom of the tank. Therefore if I did take the lower rim off the tank I could run into structural integrity problems.
Again I don't think a 20gal high tank will bow, mine doesn't. This is all dependent on the thickness of the glass. If you get a name brand tank I don't think you will have problems. I have both the top and bottom rims off. Mine has only been running for ~6 months but when I was reading up on this I found several people that have had theirs going for several years with no problems.