i love doing things myself. but would it be smart to make my own tank?

i heard you should never use metal as a base or trim.because it rusts.

A lot of people make their own tanks out of panes of glass (This is usually for those that would like to make custom fit ones for a corner or their house or usually large 100+ show aquariums.  If you are interested here is a site that you can check out:

http://saltaquarium.about.com/cs/aquariumdiy/a/aa120897diyaq.htm

I used to make my own tanks as terrariums for my tarantulas. For that is was fairly easy because I didn't have to consider the weight bearing of a large volume of water, but we did have to think about pressure points and where the tank would be situated so that we didn't end up with cracks in the glass.