There are 8, 180 gallon tanks that I assisted in making, about 5 years ago. The guy who was the lead on project owed me some $, he also owned a acrylic fabrication company. We used a $140,000 CNC router table to cut the pieces to an extreme tolerance. Everything was 100% square and true. Made it easy. We actually bonded all of the tanks at one time - just moved from table to table. We used right angle jigs to hold pieces and we really blew through it.
We had 8, 10 by 4 foot tables to work on, the jigs and the router table - made it all easy. Realistically, we could have made another 100 of them, if we chose.
My point - it was easy with the right equipment. If you want to make something tiny - a sump, small tank, etc. it is pretty easy to do. When you get into the 6 foot long tanks, you need a lot of clearance and muscle to move them around.
By the time you are done, you may be better off finding a used one on craigslist.
It takes a lot of care and patience. If you had the time and could focus on doing one side per night, by the end of the week, you would have a very nice looking tank. The trick is the polishing. the rough corners need to be dulled back and polished and any extra weldon needs to be removed.
Good luck.
