Obsidian farm

In order to make Hellstone bars, not only do you need a hellforge but you also will need Obsidian.

 You can either collect obsidian by taking a few buckets of water or lava and placing it on the opposite liquid. It would be safer to buckets of lava and place them on water. Or you can just make a small obsidian generator which is what I do.

To duplicate water and lava, make a small hook out of the blocks you desire for your small "farm". Click on the raised block in your "hook" and the 1 tile opening will catch a buckets worth of lava or water.

You will need to different sides, one for water and the other for lava. Once you get both of those filled you can start farming obsidian! Block of both sides those before filling them so you can fill both sides with the separate liquids.