All welded-up and lined with 'tank liner'. WHAT A RIP! I bought the Summit Racing fuel tank liner system. The package came with three components. First was liquid soap. Just like you would find in the grocery store. Then a quart of M.E.K. for final cleaning. Then the "Magic Super Dupper" liner. It was the exact same stuff used for gluing PVC pipe. The quart can was enough for a 12 gallon fuel tank. (what's with that?!) The kit was over $50. If I bought it from Home Depot it would have been less than $20! Grrr.