Trials and Tribulations of a Trouble Shooter
by Dr. Jerome Marks
July 1, 2009
Quality control chemists, technical service
chemists and anyone else, regardless of title, who is responsible for handling
customer complaints, requires much more than just a degree in chemistry to
solve problems. In many instances, a deer stalker hat and a magnifying glass
are necessary, in addition to an intimate knowledge of the products, their
properties and application procedures, and the conditions under which they were
applied. Needless to say, the ability to bite one’s tongue and smile when the
complaint has been proven to have absolutely no basis in either fact or common
sense is a strong plus.
Case One
On one occasion, a customer complained that a
water-based weatherproofing mastic, applied over glass fiber insulation on an
outdoor tank, had failed. Off we went to upstate New York to view the tank.
What we saw was a cylindrical tank, perhaps 30 feet high by 10 feet in
diameter. About four feet from the bottom of the tank it expanded into a
pregnant bulge.
The plant manager cut the mastic and glass cloth reinforcement, and water
poured out of the bulge. “See”, he said, “your coating allowed moisture in the
atmosphere to get into the insulation.” Despite our attempts at explaining that
if the coating had, in fact, allowed moisture in the air, under no pressure,
through to the insulation, it could not possibly retain the water at the
bottom, under a head of pressure. The plant manager was adamant – the coating
had failed.
When we asked to look at the specifications, the plant manager became highly
indignant, saying that we were not there to question his specifications, but
rather to explain why our coating had failed.
When he finally relented and showed us the specifications, cursory examination
revealed that scaffolding had been erected to a convenient height. The tank was
insulated, and the mastic applied over the insulation, to that height. No
attempt had been made to protect the open, exposed top surface of the
insulation from the elements at the end of the workday. The next day, the
scaffolding was extended, and the same procedures were followed. This was done,
one section at a time, until the tank was completed.
Whatever rainwater got into the insulation through the unprotected top went
right to the bottom, where it was retained by the weatherproofing coating. The
coating was doing what it was supposed to do – preventing the passage of water.
Only here, instead of keeping the water out, it was keeping it
in.
We then had to explain to the plant manager, supposedly a well-experienced
individual, that, even though not spelled out in the literature,
state-of-the-art decrees that insulation is applied from bottom to top, but weatherproofing
is applied from top to bottom to allow any moisture accumulation to drain out
before the system is sealed.
Case Two
One very upset customer in Texas complained that
a water-based weatherproofing mastic was “turning white and falling off the
pipe as quickly as it was being applied.” He admitted that it looked good in
the pail and “it even looks pretty good over the insulation, but as it reaches
the hot pipe it turns white and falls off”. When asked how hot the pipe was, he
blithely responded, “1,200 °F,”
A long conversation followed, in which the customer was politely requested to
reread the Technical Data Sheet in his possession, which specifically
recommended service temperature limitations of 180 °F constant, and 250 °F intermittent. In this instance, the coating was
being ashed as it was being applied.
Case Three
On another occasion, a customer was building an
addition onto an existing frozen food warehouse, which could not be taken out
of service. He was advised to put the cinder block walls of the addition in
place, insulate them and apply a xylene-based vapor retarder coating over the
spray-applied polyurethane insulation. He was further advised to leave all
walls of the existing warehouse in place until the addition was totally odor
free of the xylene from the coating. He could then break through the wall from
the existing warehouse to the addition and complete the job.
Unfortunately, this recommended procedure was considered too slow by the
contractor. He broke through the wall of the existing freezer, hung
polyethylene sheeting in the opening thus created, and then applied both the
polyurethane insulation and the xylene containing coating.
Since the vapor drive is always from the area of high pressure (high
temperature) to the area of low pressure (low temperature), and nothing was in
place other than a sheet of polyethylene to prevent the flow of solvent vapor,
someone had to “buy” a warehouse full of xylene flavored frozen food.
Case Four
One spring, a very good Canadian customer
complained that the stainless steel strapping we had provided the previous fall
was out of specification and was snapping, leaving loose jacketing over the
insulation.
A quick trip to Canada, and a few well-directed questions, determined that the
installation was subterranean, and the area had had an inordinately heavy
snowfall over the course of the winter. Lots of salt had been used to rid the
streets of snow, and the salt-laden water flowed through the sewer grates,
cascading over the insulated pipes (and the jacketing and
strapping).
The strapping, as supplied, met the required specifications but, being made of
austenitic stainless steels, was highly susceptible to stress corrosion in the
presence of chlorides, resulting in failure.
Case Five
An Oklahoma customer complained that a
spray-applied solvent-based vapor-retarder coating had lumps in the drums, and
that the solvent was dissolving the spray hoses. On arriving at the customer’s
plant, he was requested to open a fresh 55-gal drum of the product. No lumps
were detected upon close examination of the contents. There was, however, an
odor in the warehouse of a solvent, which should not have been
present.
When questioned on this, the customer advised that he had a “painter”
(translation: spray applicator) who used his own “special” solvent to dilute
the coating. This solvent, he admitted when asked, was also used to soak the
hoses overnight, in preparation for the next day’s
spraying.
It was pointed out that the “special” solvent was MEK, which was not compatible
with the base resin in the coating. This caused the resin to “kick out”,
resulting in the lumps that initially generated the complaint. The MEK was also
responsible for the solvating effect on the spray hoses. Needless to say, the
customer was advised to find another “painter”.
Case Six
One very unusual complaint was from a California
customer who claimed that a shipment of five-gallon pails of a water-based
weatherproofing mastic coating had partially solidified en route by truck. The
unusual aspect was that material in some pails had solidified on the bottom
portion of the container, while the material on top was workable. Other pails
were solid vertically, from top to bottom, but only on one side, the other side
being workable.
Sample pails of both types were returned, and the laboratory claimed that the
material had been frozen. The customer disputed this, as the truck route to
California at that time of year would not normally encounter freezing
temperatures.
Investigation of the trucker’s log, however, indicated that he had taken a
detour and spent the weekend with a girlfriend in a location where overnight
temperatures had in fact dipped below freezing.
The pails on the truck floor had frozen from the bottom up, while those on the
outside perimeter had frozen vertically, from the outside to the inside. The
coating, being self insulating, protected a portion of each pail from freezing,
and totally protected those pails positioned away from wall or floor contact.
Case Seven
The foreman of one of our very large contractor
customers ordered 60 55-gallon drums of a solvent-based interior vapor retarder
coating. When asked about the application, he disclosed that it was actually
for an exterior application, and that he preferred the application properties
of this product to those of its UV-resistant counterpart.
The foreman was advised that the product he was ordering would show signs of UV
degradation in a relatively short period of time, and that the exterior-grade
product should be ordered and used. The foreman was adamant. Either we supply
the product he requested or he would purchase it elsewhere. The order was
filled as placed.
Approximately six months later, while on vacation, I received an emergency call
from my office. The foreman had been trying to reach me on a “matter of life or
death”. I immediately placed a call to the foreman, only to have him inform me
that he was on his lunch hour, and ask whether I could call back in an hour as
it was “urgent that he speak with me”.
It appeared that, as predicted, the interior-grade coating was cracking in the
exterior application, and the foreman, who was adamant in its purchase and use,
was now requesting a letter of certification that the product could be used in
exterior applications. This, despite the fact that every piece of literature on
the product contained a caveat against exterior use. Naturally, we could not
comply. The end result was not pleasant. The entire job had to be redone with a
topcoat of the correct, originally recommended product and the foreman was
terminated.
Case Eight
A well-recognized and well-accepted marine
coating, listed on the Qualified Products List of MIL-A-3316B, supposedly
contributed to a fire at a naval base in Virginia. The flame retardant
properties of the coating were in question and samples submitted to a Naval
Ship Test Center reportedly failed the mil spec fire test placing the QPL
listing in jeopardy.
Tests run, in our laboratory, on retained samples of the batches in question,
showed far different results, each easily passing the stringent requirements.
Contacting the head of the Naval Test Center having run the tests, I suggested
the following:
1. We would supply wet samples
of each of the batches in question.
2. Both the Test Center and
our laboratory would prepare samples for flame testing per the military
specifications.
3. All samples would be flame
tested at the Test Center, with our personnel in attendance, as well as
theirs.
All of this was agreed to.
On the date the tests were to be performed, we arrived at the Test Center with
our samples only to find that:
1. The Test Center samples
were way out of thickness specification, on the high side, potentially
contributing more fuel to the flame test.
2. Each of the samples had a
layer of cardboard and/or paper adhered to one surface, adding combustible
material to a flame test sample.
Note: The “explanation” for this was that drawdowns had
been made on one surface of the specified glass fabric substrate, and in order
to coat the second surface, the sample was flipped over before the first side
was totally dry. The cardboard, upon which the fabric was resting when it was
coated, adhered to the first surface, tearing off and remaining with the sample
when it was lifted. We then had to instruct Test Center personnel on how to
simultaneously coat both sides of a sample using a coating box and two
stainless steel rods. The samples were air dried by hanging them from a horizontal
line with spring-type clothespins.
3. The Terrell burner at the
Test Center was not of the correct dimensions as called for in the
specification.
4. The Test Center personnel
who had performed the previous tests (which failed) had no prior experience
with flame testing procedures under this specification.
There were many other questionable aspects of the test procedures, none of
which was contested by Test Center personnel when pointed out. It was a
learning experience for all concerned. We learned how necessary it is to be in
attendance when tests are being performed on your products, regardless of who
is doing the testing. Test Center personnel learned from our experience how to
properly prepare and accurately flame test samples under this particular
military specification.
Conclusion
Each of the above stories is true and can be
documented. In most instances, there is a single, common theme – rely upon your
supplier. No one has better technical information on any product than the
manufacturer. Question him on all aspects of the use of his product. Ask his
advice and then, by all means, FOLLOW IT!!
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