What is a cold weld?
A. A Cold Weld is the appearance of a properly welded seam that in fact is not bonded. This may result in a seam separation. Cold Welds are the result of poor heat penetration during the welding process. Most fuel tanks use thermal welding, which is done by a hot air or hot bar process. Both only heat up a thin layer of surface of the top coating. Cold Welds may occur because of seam separation during the cooling cycle. Thermal welders do not provide any pressure during the cooling process.
