Basic Information Edit
How to proceed Edit
Tar has a base temperature of 86°F, so it can currently only become cold enough to freeze if Freeze Bombs are thrown at Tar. Arranging Snow Blowers (-22°F) and/or blocks of Ice (-5°F) around a unit of Tar, even on high altitudes with a base temperature of 5°F, is not sufficient to cool Tar down to its freezing mark.
Some players prefer to use up all of the basic and Advanced Extractors that they have found in Treasure Chests, but others will craft Super Extractors from the according rare Recipe that can only be obtained from the Thing, in order to receive the maximum output.
Tips for efficiency Edit
Before using Freeze Bombs, it is advised to create Tar-cataracts and/or deep lakes of Tar at first so you won't waste too many Freeze Bombs and get a maximum of Coal Nodes.
Since one Freeze Bomb can freeze up to 7x7 portions/"blocks" of liquid in width and usually 3-4 in depth (the maximum would be 7 again, but this is really hard to accomplish), you could dig a 7x7 wide hole 4-7 blocks deep and fill it with Tar to optimize the amount of Coal Nodes created.
To fill a hole properly without leaving any empty spaces you might want to build bridges over the hole one after another and place the Tar on each block of the sides of the bridge, or create a "roof" where you can place the Tar on from down below. Or you can create a "ceiling" of 7x7 blocks and stick Tar to it from below.
Throwing Freeze Bombs directly down usually yields the best results, since Explosives can only be thrown in an arc; so any auxiliary constructions like ceilings or bridges should be removed before using Freeze Bombs on the Tar pool or cataract.
How to proceed further Edit
Coal Nodes can be made into Diamond Nodes by throwing Fire Bombs or Flaming Skulls at the Coal Nodes, see: Making Diamond. Again, one Fire Bomb or Flaming Skull can usually only turn 7x7x3 or 7x7x4 blocks of Coal Nodes into Diamond Nodes, the theoretical maximum would be 7x7x7.
Before throwing these Explosives, please make sure that the option "Disable Fire Spread" is deactivated on the game world, and "Fire Sim Enabled" is activated on the according player claim. These options can otherwise both completely negate the effects of Fire Bombs and Flaming Skulls, together with preventing flames to spread to any nearby flammable material/blocks.
With update R26 in December 2015, the balance for creating infinite amounts of Coal (and Diamond Ore) was changed significantly. "Coal Towers" that could be simply made from Ice before that date will not produce Coal any longer, since Tar now flows significantly slower and fills one block after another with a new Tar-source each that does not cool down deep enough by being surrounded by Ice blocks. Tar can now only be made into Coal Nodes by using Freeze Bombs.
Since update R34 in September 2016 the crafting recipe for Freeze Bombs also requires to craft Iron Mining Cells and Armor-Piercing Bombs to be unlocked, while the Freeze Bombs themselves need to be made with Rambeau Tufts and Blizzard Chizzard Gizzards as ingredients, which makes them rather "expensive".