There does not seem to be a clear and reasonable distinction between moldmaking and mold repair. Applicants for in-house mold repair shops are quizzed about their moldmaking experience with the obligatory “Do you have any experience doing repair work?” question tagged on.

Though mold building and mold repair employ some of the same basic skills, they are two separate and distinct job classifications. Following are just two factors that contribute to the lack of clear distinction.
1. Molds being one-off and unique cannot by virtue of scale support the specialties required to deal with ongoing issues during the useful life of a tool. If molds were as numerous as cars there would be separate classes of technicians to deal with gating issues, cooling issues, cavity damage, mold action problems (with a sub-category of specialist to deal with hydraulic actions) and hot runner specialists.

Obviously there are isolated individuals who specialize in each of these areas and they provide an invaluable service to the molding industry. The problem is that not every molder has ready access to these specialists. Though the requisite specialties cannot be supported by virtue of scale, molders must by virtue of necessity staff their in-house repair shops with people they hope turn out to be multi-specialists.

2. Economic investment. A mold builder has to make significant investments in software and machine tools—the cost of which can be distributed over many molds. In contrast, most mold repairs do not require engineering software and expensive machine tools, and the relatively few times such equipment is required makes it difficult to justify the investment. So, those types of repairs by default remain largely the responsibility of the mold builder.

It’s probably safe to say that most mold builders do repairs to keep customers happy rather than any real desire to be involved in that line of work. It’s never convenient to break into a shop schedule to expedite an urgent repair.