Soapy water is used to repair armor and tools, and is used in the Washing Machine and Dishwasher. It is useful if you are starting out and don't want/can't afford Super Soapy Water, it is also used in the crafting recipe for Super Soapy Water.
Crafting Recipe EditSoap above a bucket of water.
and the crafting recipe for the soap just click the red soap thing up there so just click and recipe for soap! thanks fo coming here :D