Oh, sorry, I forgot when the Beenades got added. In that case you could try using dynamite, though you have to properly time it. If you get the correct timing, you can deal a lot of damage to it, but it's also more risky, for obvious reasons.
You may want to obtain the Phoenix Blaster, the best ranged weapon you can get before the start of hardmode. Be sure to use Ironskin and Regeneration Potions to increase survivability fighting the WoF. If you need extra defense, trying using the Molten Armor and reforge your accessories to Warding or similar defensive modifiers.