[South Florida DX Association] Corrosion Control Even With Gold Connectors
[email protected]
[email protected]
Tue, 11 Nov 2003 19:48:18 EST
The following material sounds very good, also check the web site out (Tampa
location - http://www.lektro-tech.com/pages/2/index.htm) for more specifics.
If the club is interested, it may be a good idea to do a "club" purchase to
take advantage of standard "box" prices. I don't have any costs as yet, but I
would like to know if anyone would like to participate. Based on the response I
will get more info.
See comments below -
Norm W4QN
---------------
> From: "Horne David H Civ OO-ALC/YPVS" <[email protected]>
> To: <[email protected]>; "Collins" <[email protected]>; "Rocco
> Lardiere" <[email protected]>
> Sent: Monday, November 10, 2003 12:01 PM
> Subject: {Collins} Corrosion Control Even With Gold Connectors
>
>
> > Scott, Rocco, Dennis:
> > The experience and learning the Air Force has accomplished in the last
> > 15 years about corrosion in electrical connectors may be of interest and
> > substantial benefit to all of you. The F-16 fighter is a marvelous
> machine,
> > but it has significant corrosion problems with electrical connectors even
> > with Mil-Spec hard gold/gold plated connector contacts. In addition there
> > are both fretting and galvanic corrosion with connector sets with tin
> plated
> > pins matching to gold plated sockets. One aircraft crash cited short
> > circuits in an electrical connector as the probable cause. There is
> > persuasive evidence that more mishaps have been due to corrosion and short
> > circuits or high resistances in connectors. In fact, there is persuasive
> > evidence that other USAF aircraft have had multiple mishaps due to
> connector
> > corrosion. The AF has contracted with Battelle Memorial Institute in
> > Columbus to study the problem, and the results of considerable testing
> > reveals all electrical connectors may be at hazard for corrosion. And
> they
> > identified an inexpensive, easy, and long lasting solution.
> > This started in 1986 when an aircraft was on final approach into a
> > Texas air base, and the engine flamed out. The most dangerous times in
> > flight include takeoff and landing, but the pilot was able to glide far
> > enough to land on the runway overrun and roll to a stop. That started an
> > expensive but very profitable research program that the AF now is nearly
> > prepared to implement treatment of F-16 connectors and already has begun
> to
> > implement on some other aircraft. The connector treatment implementation
> is
> > expected not only to significantly improve safety, improve the aircraft
> > reliability, increase the mission capable status of the aircraft on the
> ramp
> > but also reduce number of computers, radar, communications and other boxes
> > that are sent to be overhauled. That reduction in sending boxes to be
> > overhauled in a 2.5 year study resulted in the cost savings averaging
> about
> > $600,000. per aircraft per year at one base where that data were analyzed.
> > It also reduced the maintenance man-hours about half for those aircraft
> > treated.
> > Battelle found that half of the products being sold to the DOD to
> prevent
> > corrosion in electrical connectors actually accelerated corrosion in some
> > tests all of which (except one) were qualified under the Navy's
> > specification MIL-C-81309. Battelle contacted all the companies that
> claimed
> > their products were corrosion inhibitors but caused corrosion, and none of
> > them had done any testing to substantiate their outrageous claims.
> However,
> > Battelle identified MIL-L-87177A Grade B (invented by the Bell Labs for
> > their own use) as an excellent corrosion inhibitor for connectors that
> > lasted for a full two years. Fred Meyer at the AF Materials Lab heard
> about
> > it and wrote a specification to describe it. In fact, that 2.5 year study
> > was done on gold to gold connectors only, and the mean time between
> failures
> > of black boxes (called line replaceable units = LRUs) was extended as much
> > as fifteen times (on the flight control computer). That is a spectacular
> > improvement, and the mission capable status was improved 15%, also
> > spectacular. Not known to the AF at the time the Dept of Energy that has
> > some association with ICBMs tasked the Sandia Labs to study so called
> > corrosion preventive compounds and came to a similar conclusion as the
> > Battelle Labs. On the Sandia team was the former Bell Labs scientist
> James
> > T. Hanlon, an Extra Class Operator, W8KGI. The final report of their
> study
> > was entitled, "MIL-L-87177 Lubricant Bulletproofs Connectors Against
> > Chemical and Fretting Corrosion."
> > The following characteristics show why it is such a super corrosion
> > preventive compound (CPC). It has a very low vapor pressure so that
> flying
> > up to 70,000-feet will not cause it to evaporate and disappear. It is
> > liquid from -70-deg F to 550-deg F. The surface tension of water (moisture
> > from the air, too,) is high so H2O tries to go into a sphere, but the
> > MIL-L-87177A Grade B has a low enough surface tension that it can go right
> > under the water where there is a slight void and expel the moisture in
> > cracks and holes in the metal. It is not miscible with water so
> thereafter
> > the moisture from the air cannot penetrate it and get to the metal. The
> > Royal Navy has found that even electrical connectors in their salt water
> > "bilge" tanks that are emptied to surface and filled to dive are
> unaffected
> > by the salt water; they love this stuff. Also, some of the F-16 users who
> > participated in the test program still are using the material although the
> > test program is over, because they saved so much time, improved their
> > mission capable rate so much, and saved so much money. No damage to
> > connector materials has been seen, and the chemicals all have been tested
> to
> > assure no hazardous effects to the users.
> > I recommend NASA look at using this CPC, because it promises to reduce
> > their corrosion problems significantly and perhaps end the corrosion
> > connector problems altogether. The same goes for all of your amateur
> radio
> > connectors. I buy it for my coax outside and treat all the connectors in
> my
> > shack and my computer connectors and card edges. It not only acts as a
> fail
> > lubricant to prevent gold smearing but also prevents the gold and all
> other
> > metals from corrosion. Battelle found that enough corrosion occurred with
> > gold to gold connectors to cause intermittents and shorts in only six
> > months. What really happens is that the copper or the nickel under the
> gold
> > sees the gold as a dissimilar metal and is corroded by the more noble
> gold. The gold probably does not corrode.
> >
The National Stock Number for the MIL-L-87177A Grade B is
>
> > 6850-01-328-3617, and the two qualified vendors are
Lektro-Tech, Inc,
4302 > Henderson Blvd,
P.O. Box 18566, Tampa, FL 33679, 813-254-1380e-mail:
> [email protected], and
> LFC, International Lubrication and Fuels Consultants,
521 Quantum Road, Rio Rancho, NM 87124, 505-892-1666,
> [email protected], www.ilfc.com.
> It is a little expensive, but we calculate we are saving in the realm $500.
> to a $1000 for each penny spent on the CPC.
>
> > David H. Horne, P.E., WA7LJU
> >
> > -----Original Message-----
> > From: Scott Johnson [mailto:[email protected]]
> > Sent: Saturday, November 08, 2003 9:33 AM
> > To: Collins; Rocco Lardiere
> > Subject: {Collins} Re: gold connectors
> >
> >
> > the problem is that the gold flash on the cheap connectors is not thick
> > enough to server as a barrier coating, and in many instances it is not
> even gold, it id titanium nitride which is a crappy conductor
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