If moldmaking and mold repair are indeed two separate entities the question becomes “What are the specific skill sets required for a mold repair technician?” Unfortunately the answer may be largely influenced by the specific repair environment. That is to say, if the in-house toolroom is fully equipped, the level of repairs may be quite a bit more complex than those performed in a bare-bones, band-aid shop.

If the molder has a specialty (i.e. automotive, medical, consumer products, etc.), the repair expectations may be entirely different and so too the attendant skills needed to accomplish them.

Repair Defined
One last major issue to wrestle with is the definition of repair. A repair can be anything from replacing a broken water line to troubleshooting an electrical problem to re-qualifying a damaged cavity.

All caveats considered, let’s agree to be specifically general (oxymoron intended): specific in regards to the distinction between building and repairing; and, general in regards to the variety of environments likely to require repair technicians.

hen speaking of skills almost by default, hard skills are the first to come to mind. These hard skills are those that overlap with mold building. In at least some measure, machining skills are required of a repair technician—at a very minimum, a fairly high degree of facility with the basic machine tools: lathe, mill and grinder. Even in environments with minimal repair expectations, replacing ejector pins, remaking damaged core pins and removing galled tooling are functions that require the use of manual machine tools. In the world of molds, the word welding is almost synonymous with repair. A technician with excellent welding skills is a rare find.

Other skills would include familiarity with measuring tools and practices, the understanding of mechanical functions—specifically the functions of mold actions, a basic comprehension of how molds operate and the need for draft and shrink. Math (trig) skills are high on the list and print reading/sketching skills are also very helpful.

A repair tech needs to be able to do the routine remove-and-replace repairs that entail swapping out worn or damaged components, yet some of the more valuable skills are on the soft end of the scale.
Ability to do root cause analysis—to provide best practices information for improvements in future builds.
Trouble-shooting skills—the systematic elimination of possible causes from simple and easy to complex and difficult.

Diagnostic skills—the ability to read the evidence on the mold surfaces; to judge the shutoffs, gas trails, resin build-up, PL hobs, gate strings etc.
Knowledge base—how plastic flows, conditions that cause flash, gating requirements, venting requirements, temperatures and pressures involved in the molding process and how these affect and are affected by mold design and condition .

These are the types of skills that are developed over time by individuals that are motivated by passion more than a paycheck. People whose normal practice is to analyze situations, compare results, build on experience and brainstorm innovative solutions. In the end, it’s solutions that matter, the requisite skills come full circle where the soft informs the hard and together they produce a repair that gets the mold back in the press doing what it was designed to do.