anybody ever attempt to build their own tank?

ive taken some interest in making one of my own and read a few write ups online and it doesnt seem like it would be *too* difficult. i cant afford a big tank (i have a 28g and id like to go bigger, maybe 40+) so it seems like a reasonable alternative as long as i take my time and water test it in the garage to make sure it holds up.

edit: had to hit "post" cuz my boss was on his way over.

anyway, im looking for feedback from anybody who has tried and succeeded or failed at making their own tank, also maybe an idea how much you spent, how big you went and if you have any material recommendations.