Here are a couple pictures of my metal frame tank. I think its a 29g (30"x16"x16") These were how all aquariums were built back before silicone was used to seal tanks. They used to seal with a waterproof putty that would dry out and crack in about 10 years. After my grandpa gave it to me about a year ago, I applied silicone cauk to all the outside parts and it still works to this day!
Let me know what you think!
P.S. I have a cover and lights but I took them off so you can see the top lip.

P.S. I have a cover and lights but I took them off so you can see the top lip.