Oakum
Oakum can be used to seal cast iron pipe drains. After setting the pipes together, workers pack oakum into the joints, then pour molten lead into the joint to create a permanent seal. The oakum swells and seals the joint, the "tar" in the oakum prevents rot, and the lead keeps the joint physically tight.
Today, modern methods, such as rubber seals (for example, gaskets or o-rings) are more common.
Seam sealant
Seam sealing was already performed manually successfully for preventing perforation corrosion in the 1980s. Today used in the OEM automotive industry primarily for the purpose of seals against air leaks and to waterproof sheetmetal overlaps that occur in the assembly of a vehicle. Such overlaps are typically decorative rather than structurally supportive. Accordingly, they are usually only spot welded and this process results in a closure that is not air or water tight.