Combine the potatoes, Creole seasoning, thyme, bay leaves, garlic, lemons, boil seasonings bag and onion with 6 quarts cold water in a 14-quart or larger pot with a colander insert. Cover and bring to a boil; reduce to a simmer and cook 10 minutes.
Add the andouille and corn to the pot. Cover and simmer an additional 15 minutes. Add the crawfish, cover again and cook 10 minutes. Add the shrimp and stir to combine. Cover and cook for 4 to 5 minutes more. Carefully strain the seafood, sausage and vegetables and serve on a large table covered with newspaper. Season with salt or additional Creole seasoning.