I'm not too sure how to do this I have try but it wont work.

I suggest you look into ICraftingHandler. Feel free to adapt my Crafting Handler for TFC to your needs

try using some of the code that I already made,

put

GameRegistry.registerCraftingHandler(new NewCraftingHandler());

into your base class PreInit Method

 

Then, you will need to have something check all your inv slots:

public class NewCraftingHandler implements ICraftingHandler {

public NewCraftingHandler() {
}
@Override
public void onCrafting(EntityPlayer player, ItemStack item, IInventory inv) 
{
	for(int i=0; i < inv.getSizeInventory(); i++)
	{
		if(inv.getStackInSlot(i) != null)
		{
			ItemStack j = inv.getStackInSlot(i);
			if(j.getItem() != null && j.getItem() == TestMod.item)
			{
				ItemStack k = new ItemStack(TestMod.item, 2, (j.getItemDamage() + 1));//makes 2 items, 1 that is used and 1 that is damaged
					inv.setInventorySlotContents(i, k);//i is slot, k is Item
				}
			}
		}
	}
}

@Override
public void onSmelting(EntityPlayer player, ItemStack item) {

}

}

then press ctrl + Shift + O, and that will import all needed things

Hope this helps!