In a large pot, bring the water to a boil over high heat.
Add the Old Bay seasoning and salt to the boiling water. Make sure you stir well to dissolve the seasoning.
Carefully add the potatoes to the pot and cook for about 10 minutes or until they are just a few minutes away from fork tender (they will have more time to cook later).
Add the clams, corn, sliced lemon, minced garlic, and smoked sausage to the pot.
Cover the pot with a lid and cook for 5-7 minutes more or until the clams have opened and the corn is tender. Discard clams that did not open.
Remove the pot from the heat and drain the seafood boil.
Transfer the cooked seafood, corn and potatoes, and sausage to a deep dish or a large serving platter.
Drizzle the melted butter over the seafood boil and sprinkle with fresh parsley. Prepare the extra lemon wedges on the side for squeezing over the dish
Make sure you serve the seafood boil with clams and lemon immediately before the butter gets cold.