CH 16 - Equipment Usage Beyond Design Parameters / A Mysterious Disappearance from a Ring Box
Apr 15, 2009

CH 17 - Identifications from Video Surveillance Cameras / Exploding Microwaves
Apr 15, 2009

CH 18 - Exploding Sink Drains / Suntan and Massage Lineament Burns / Burns from Hair Colouring Chemicals
Apr 15, 2009

CH 19 - Seed Grain Deterioration / Plastic Food Trays
Apr 15, 2009

CH 20 - Furnace Element Failures
Apr 15, 2009


CH 14 - Defective Sinks / The Old Tractor Trailer Tanker
2009-04-15
Defective Sinks

During the construction of a luxury hotel a number of the suites were equipped with artificial marble vanities. After a relatively short portion of their expected service life the sink surfaces began to crack in a peculiar manner. The crack patterns were unsightly and the hotel owners asked the manufacturers for help in correcting the problem. The supplier refused to provide assistance and denied all responsibility in the premature failure suggesting that improper installation and the use of strongly alkaline abrasive cleaners had caused the problem. The refusal to co-operate left the building owners with no option but to sue. In the ensuing trial it was demonstrated with simple physics that the cracks had developed due to shrinkage in the polymer used to manufacture the sinks. It was also brought out that the epoxy based product would normally be given a heat treatment step to ensure that the polymer had fully cured and would not shrink when in service. The manufacturer had omitted the heat treatment step and over a relatively short time period the structure shrank stretching the surface glaze, which then cracked in the peculiar manner observed.


The Old Tractor Trailer Tanker

We received a request from a trucking company dispatcher to examine a stainless steel tanker trailer in a repair facility yard. The unit had been built in the late sixties and had failed a mandated pressure test in the mid nineties. The unit was leased from an out of province owner who now demanded compensation for the unusable vehicle. The owners of the tanker sued the trucking company suggesting that the chemicals being carried by the transport company caused the deterioration in the tank. The haulage company had only leased the trailer for several years and felt that they had not abused the vehicle during the time it had been in their possession.

The stainless steel of the tank had suffered from a form of corrosion, which is more a problem of aging rather than hard usage. Many forms of stainless steel cannot be exposed to common table salt. The salt causes the deterioration of the stainless to accelerate when the steel is placed under load. Over the time period from the late sixties until the early nineties it is difficult to imagine how the tank could not come into contact with materials containing low levels of salt. Road salt is able to cause the steel to deteriorate.

The haulage company however used the tanker to transport water solutions containing chemicals that are used commercially to preserve stainless steels. From the chemical point of view the transport company contributed to the longevity of the stainless steel structure not its demise