I have a tool and its welded (improperly i guess?) but every time you take it out it works good. Then when you unequip it then reequip it it'll act like it's not welded. Do I need a script for the weld?
Go play water polo
Yes. Whenever welded parts are taken out of the workspace, all welds on them are destroyed. That's why all multi-part tools have a weld script in them that re-creates the welds every time the tool is equipped and unequipped.