Vacuum Furnaces, Water Leaks and Bill Clinton

Major Mike

I got called into work at 0730 Saturday morning. I hate getting called into work, but it comes with the territory of being a Maintenance Manager.

First a little background on Titanium vacuum furnaces.

Vacuum furnaces are used in many casting applications to eliminate contaminates from the castings. Low vacuum…low amount of oxidants…low levels of contaminations…better parts. But melting metals in induction furnaces requires significant amounts of heat…heat generated by inducted electricity. In this particular furnace an enormous “stinger,” via a 20’ hollow metal tube, cooled internally by flowing water, holds an “electrode” of solid titanium. The electrode is lowered into a crucible that has an electrical coil wrapped about it, and the titanium is melted, much like the activity that would take place at the end of an enormous welding rod. The molten titanium is then poured into the ceramic mold. An aircraft engine part is made.

I was called into work, because over the course of Friday night we had to replace the stinger…a water leak outside of the vacuum areas of the furnace, but a water leak that, upon further investigation revealed a couple of fissures at the mount point of the stinger. The stinger was removed, the replacement was prepared.

I was called in.

At a critical point at the end of the “stinger” purified copper is “welded” to the steel “stinger.” This allows for a better flow of electricity into the business end of the “stinger.” The integrity of this weld is critical in keeping “stinger” cooling water out of the furnace. A failed weld leads to water into the furnace.

Water poses a couple of problems in vacuum furnaces. The first is…water will wreck vacuum, and degrade quality. H2O…Hydrogen, and Oxygen will be detected by the vacuum gauges, and potentially interrupt the pouring sequence as contaminate limits are exceeded. Fairly minor, but a quality problem nonetheless.

The second potential problem…explosions. If a large enough stream of water is able to make contact with, and penetrate the molten metal in the crucible…the hydrogen molecules will be separated from the oxygen molecules…and then, with the residual heat/spark provide the conditions needed to sustain combustion. Large and rapid combustion...a.k.a. explosion.

A few years ago…while I was working at another place…water and molten titanium met, and blew the roof off of the plant…sending pieces of the furnace and the plant into the surrounding neighborhoods. Employees are understandably sensitive about the condition of the stingers and the potential introduction of water into vacuum furnaces.

As my experienced team began to install the replacement stinger, they noticed some potential defects in the facing of the stinger…in the area where the copper is welded to the steel. I was called in to make “the call.”

We called in the vendor who had done the difficult welding (brazing actually). I paged my most experienced technicians. We got as much info as possible.

The vendor showed up…with the welder that had actually completed the work. Both could clearly recall the previous repair. Both could outline their procedures, and the depth of effort of which they had undertaken to met our complex need. They had contacted experts, detailed their procedures, and double-checked themselves along the way. They assured us that the weld was good, and the defects we were seeing, were very minor pass (welding passes) defects, that were exposed in the final machining of the stinger end.

My team and I moved on to the details of passing electricity through the minor defects and into the cooper end that ultimately transfers electricity into the titanium electrode. We felt that these defects would not noticeably affect the transfer of 40,000 amps of electricity into the electrode.

I…me…myself…the one and only…made the decision to install the stinger, and to resume production.

I was more than a little disappointed to have to pull that stinger today, as it was leaking small amounts of water into the furnace. There was a water leak, not along the areas of our concern, but no doubt along the weld line.

But, I didn’t blow a gasket…get a throbbing vein in my head…ramble on about the last person that blew up the furnace…or, trash a vendor who had made an honest effort at making a difficult repair.

I calmly explained to the department manager all that we had done, and where the new failure was actually located. This calm reassurance, let the manager know that we had done our utmost in resolving his initial problem.

We analyzed the situation, took in all the evidence, assembled a talented team, reviewed production requirements, and I made the call. I would make the same call again, and defend it…and I wouldn’t have to get red in the face in my defense. Sometimes, when presented with the best evidence, and given the best advice of experts, the cards still don’t fall where they are expected to.

But one thing that the Marine Corps taught me, and Bill Clinton should know as a former Commander-in-Chief, you MUST take responsibility for your command decisions, and that blaming others, shifting focus, lashing out, and spittling oblique accusations onto others, is not the way of a leader…but more the way of a self-centered, egotistical, legacy defender…and not the stuff that officers are made of…let alone Presidents.

We are changing out the stinger again this evening…I have not had to provide a red-faced, spittle-laced defense for my actions. It was recognized by all as the “command decision” it was. We may change our repair techniques, and/or our certification of stingers after repair, but I did not feel compelled to lash out at the department manager who is asked why he lost a day of production, I merely explained in calm detail what we had done. He simply asked for the fastest turnaround possible.

Our vendor is working through the night…my team is ready for the re-install, and no one lost their temper…let alone their dignity or their stature.