A Certified Woman Owned Business Enterprise (WBE)

Issue 30

Publisher:  Jack Burlin                                Editor:  Patti Hammonds

December 3, 2007

IN THIS ISSUE
Your success story            Monthly featured product            Kevinisms            Trivia         

Articles of Interest:  Whiskers in the Data Center                      The 50 Cent Watch

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Your Success Story

Monthly Featured Product

Whiskers In The Data Center
What You Need To Know About Zinc Whiskers
 

July 27, 2007 • Vol.29 Issue 30

Whiskers—they’re supposed to grow on cats and men’s faces. Unfortunately, they also grow in the data center where, when left unchecked, they can wreak havoc with sensitive electronics.

First identified in the late 1940s by Bell Labs, these tiny, hair-like filaments grow out of zinc-electroplated surfaces (galvanized) commonly found in data centers’ physical infrastructure, with the most common culprit being wood or composite floor tiles with flat metal sheeted undersides. Zinc electroplating is still in use today and may very well end up in the data center, especially in equipment manufactured overseas, particularly in China.  However, the electroplating process is different today—a rolled process—that is believed to reduce whiskering.

According to Jay Brusse, who studies metal whisker formation on metal surfaces for NASA, zinc whiskers can remain dormant for years and then suddenly become active, growing as much as 1mm each year. While that may not sound like a huge problem, zinc whisker contamination can result in intermittent and outright failure of electrical circuitry. IBM (www.ibm.com) has long identified zinc whiskers as the cause for operational problems in its AS/400 Physical Planning Reference handbook.

Powerful Stubble

Despite their minuscule size, zinc whiskers are metal and, therefore, conduct electricity. Easily dislodged and dispersed into the air when disturbed by normal actions, such as moving floor tiles or equipment, these tiny particles are easily drawn into equipment that has powerful cooling fans.

When airborne zinc whiskers settle on integrated microcircuit boards, the most likely result is an intermittent short, a temporary variance in voltage or signal disturbance. In severe contamination situations, catastrophic equipment failure can occur.

Failures due to zinc whiskers are difficult to identify. During the short, the micron-thin zinc particles are often vaporized by the current. Also due to their nearly microscopic size, when the affected equipment is opened or moved for repair, the offending whisker can easily become dislodged, leaving no trace of the problem. As more professionals become aware of the threat from zinc whiskers, they are taking a closer look at their data center environments.

Understanding what to look for is critical when assessing the data center for zinc whisker risk. Data Clean (www.dataclean.com), a company that offers zinc whisker remediation services, advises to first check to see if there are any flat-bottomed access panels that are wood-core, composite-core, or concrete-core, as well as ferrous metal pedestals and stringers. Dimpled-bottomed panels and aluminum pedestals and stringers are not at risk. Next, examine the finish of any exposed metal. If the metal is a uniform dull gray with a slightly shiny finish, it could be at risk for zinc whiskers. If the surface is a mottled finish, the zinc plating was applied using the hot-dip galvanization process, and there is no risk of zinc whisker formation, even on flat-bottomed access panels.

If there is sufficient evidence of risk, there are a number of methods to see if zinc whiskers are actively forming on a surface. The quickest method is to visually inspect the surface from the side using a flashlight. Whiskers range in size from 1 to 10mm and appear as shiny hairs protruding from the metal’s surface. It is important to be cautious when handling possibly contaminated floor tiles, as whiskers can easily break off.

Even if whiskers aren’t visibly apparent, that doesn’t mean they aren’t there. If a zinc whisker contamination is suspected, another method that can easily be performed by data center personnel is wiping a number of surfaces throughout the data center with a specialized wet wipe. The wipe is then sealed in a plastic bag and examined by a professional environmental lab which will then test the wipe for zinc. If the lab determines the presence of zinc on the wipe, the next step would be to turn to a company offering professional zinc remediation services, such as Data Clean or Sterile Environment Technologies (www.set3.com), which routinely turn to Scanning Electron Microscopy examinations prior to instituting remediation measures.

Decontamination

When zinc whisker contamination has been confirmed and professional services have been engaged, there will be a lot of unplanned activity occurring in the data center. It is essential to work closely with remediation service personnel in order to ensure success. Although professional zinc whisker remediation is an expensive undertaking, compared to the downtime and instability within the data center due to contamination, it’s well worth the cost.

Be prepared to power down the room and possibly the entire data center, as the cooling system will need to be shut down to reduce airflow. If equipment cannot be removed, it should be tented and sealed with plastic sheeting. Affected access panels, pedestals, and stringers will need to be carefully removed and sealed into individual plastic bags prior to removal from the premises. Using HEPA vacuums and wet wipes, clean all surfaces, including the plenum, remaining floor areas, walls, ceilings, and any equipment left in the room prior to installing new, uncontaminated infrastructure.

Mitigation

There are no environmental controls such as temperature and humidity to reduce or eliminate the growth of zinc whiskers on zinc-plated metals. Due to their size, normal dust filters in cooling systems fail to remove whiskers from the air. HP (www.hp.com) has been working on an electrostatic precipitator that would remove airborne zinc particles in the cooling systems using an electrostatic charge. The Uptime Institute recommends replacing all tiles capable of producing zinc whiskers and cleaning the affected room.
 

by Sandra Kay Miller

     They say you can tell a fighter pilot by the size and complexity of his watch.  True to form, I had a watch that I bought as a senior in college.  This watch had a stop watch function, had markings on the dial to allow you to calculate speeds up to 600mph, and a few other nice features.  I wore this watch throughout my Air Force career, but it was a bit sensitive, and certain functions seemed to fail pretty regularly.  The last time the stop watch function failed, I decided to retire the watch rather than pay $100+ to have it fixed again.  Since I wasn’t flying any longer, I did not really need the impressive watch any more. 

     At a garage sale in Stamford, CT I happened to see a watch that looked interesting.  It was a rectangular face and body, with a small set of hands in the center.  It was gold color with a white face.  Since I needed a watch, I purchased it for 50 cents, and put a new leather band on it.  It worked fine and looked pretty nice.  A couple of weeks later I was enroute to Islamabad. 

     As a Systems Manager for a large Aerospace company, I made frequent trips to visit the Pakistani Air Force and Army.  Most visits were to the capital in Islamabad, but I also got to visit Karachi and some other cities. 

     On this particular trip, I stayed at the Intercontinental Hotel in Rawalpindi.  Rawalpindi is the twin city of Islamabad, and was the capital of Pakistan before the government built all their offices and other buildings nearby, naming the new city Islamabad. 

     The trip was pretty successful, with visits to the Army Chief of Staff, the US Embassy, and a couple of other places.  In between appointments, I visited the various gift shops in the hotel.  One store in particular attracted my attention.  This store sold semi-precious stones and various carvings made from the stones.  I had my eye on some Lapis Lazuli and some Malachite. 

     As the time for my return to the US neared, I went down to see what might be within my price range.  There was a spectacular carving of a hippo in Lapis, but they wanted $400 for it.  There were raw pieces of Sodalite, Lapis, Malachite, Rhodonite, and a few other things.  I had gotten friendly with the man running the shop, and started to negotiate over what I wanted.  As we were talking he noticed my watch.

     I was making offers for various items, but he was fascinated by the watch.  He asked me how much I wanted for the watch.  I told him it was not really worth much, and that if I gave it to him, how would I tell time on my way back?  He persisted.  He wanted to know how much I would take for the watch.  I explained it only cost me 50 cents, and that it really was not worth trading for.  He insisted, "How much do you want for the watch?"

     Not wanting to take too much advantage of the situation, I finally said $50.  He said that was fine.  I could have $50 worth of stones in exchange for the watch.  This seemed like a great deal to me, so I got a few large pieces of different things.  Lapis, Malachite, Sodalite, and Rhodonite (see pictures below)  all got stowed safely in the luggage and made it back to Stamford with me.

     I am not sure what made this man so interested in my watch.  Maybe he was a better judge of its value than I was.  It seemed to me that watches were readily available in Pakistan, so I still can’t figure out why he wanted it so badly.

     I felt I made out well, but then I started to wonder how much value I could have gotten for a fighter pilot’s watch.  It should easily have been worth a $400 carved hippo.

 Thanks for reading, and I hope you enjoyed this month's newsletter. 
Please direct your comments to Jack Burlin.

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