there is, but it might be easier to just make a new tank yourself. you would need to first separate one side from each tank(rremove the glass), and then figure out a way to connect the 2 tanks together, without leaving any gap in between....
You could also look at stacking the two on top of each other. Just invert one and hinge them on the back. I've never done it before but have seen a couple of tanks like it. if your looking for a taller tank that is.
I think Klik did combine 2 10 gallons together. I believe he put one on top of the other. Why don't you ask him if he doesn't catch this thread.
I think it would just be easier to build yourself a custom new enclosure. Turning Two tanks into one could be a real chore.
Unless you like to display your animals, Rubbermaid & Sterlite tubs are always an option. I currently have my ball pythons in separate 74 qt. Sterlite tubs. They measure about 44x20x6.5 inches, & ran me about $12.99 each at Target. Of course, this is no way to display your ball python, but it tends to make the best use of space, & it's much easier to keep clean. Good luck w/ your enclosure. -Prttyhtmchn