NBTTagCompound tag = new NBTTagCompound();
// Smeltery stuff since 1.7.1
/* 
This part adds Smeltery melting. Give it an item, a block to render in the smeltery, the temperature required and the liquid to produce.
   For reference: Iron has temperature 600, Stone has 800, Water has 20.
   Melting duration is directly related to temperature required. 
*/

// the item
item = new NBTTagCompound();
(new ItemStack(TinkerTools.materials, 1, 2)).writeToNBT(item); // seared brick item
tag.setTag("Item", item);

// the block to render
item = new NBTTagCompound();
(new ItemStack(TinkerSmeltery.smeltery, 1, 4)).writeToNBT(item); // seared stone block
tag.setTag("Block", item);

// liquid to produce. This time the amount DOES matter!
(new FluidStack(TinkerSmeltery.moltenStoneFluid, Construct.ingotLiquidValue/4)).writeToNBT(tag); 

// the temperature required
tag.setInteger("Temperature", 850);

FMLInterModComms.sendMessage("TConstruct", "addSmelteryMelting", tag);