Proprietors of ships and shipyard companies word-wide collaborate with steel manufacturers, lacquer producers, specialized service providers and engineering offices to optimize the safety, cost-efficiency and quality level of operating, building and overhauling boats and ships. Among Germany, the most important countries involved in the building of steel ships are South Korea, Japan, China, Poland and Croatia. Staff working for classification societies and engineering offices monitor the separate steps of work in all shipyards, ensuring a quality classification of ships for insurance companies and the registration in the register of shipping. In this regard, inspection of the construction as well as monitoring of coating work are executed according to international standards when building and renovating ships, as the classification societies, organized under the umbrella organization IACS (International Association of Classification Society LTD) and the IMO-member countries (International Maritime Organization) have agreed upon harmonized standards. The most important goals of lacquer and anti-corrosion coatings as well as its control during inspection and renovation work are to prevent corrosion damage resulting from aggressive salt water and the growing of sessile organisms on a ships outer hull thus ensuring a safe and cost-effective operation of the ship.

Professionals know: corrosion never sleeps
Due to the experience that “corrosion never sleeps”, and because corrosion endangers the stability of a ship [1], the separate areas of a ship are coated differently and accurately according to their particular kind of exposure. Therefore, the highly exposed hull below waterline and the ballast tanks, for example, have to be protected with a cathodic corrosion protection combined with coating systems [2]. Inside and on deck of ships epoxy based coating systems usually guarantee a reliable anti-corrosion protection. Whereas special antifouling coatings reducing fouling on the hull below waterline [3][4] result in reduced head resistance and an increased cost-efficiency of ships.

For these different multi-layer protection systems to be applied professionally and documented, a methodical procedure of coating work is required following the ISO 12944 as well as other standards [5][6][7] and the resolution “Performance standard for protective coatings“ which will probably be in effect from 1st July 2008 onward [8].

Concerning this resolution, a generally recognized training of inspectors has been demanded, as the shipbuilding industry world wired currently bases such a training mainly on the originally Norwegian FROSIO- the British ICORR and the US NACE certificates.

The modular QNix® 8500 measuring system in corrosion protection management
Precise, robust and at the same time easy-to-use measurement devices are required to ensure a high quality standard of professional execution in corrosion protection and for the management of complex projects. Paint Gauges and coating thickness systems for determination of coating thickness are used in different areas. Despite the various measurement conditions such as the different kinds of steel used in ship building workers must be able to rely on the accuracy of measurements taken. In this regard, measurement principles according to ISO 2808 [9] have been established, helping to non-destructively determine the coating thickness in wet state using measurement combs (fig. 1) as well as in dry state using magnetic measurement methods (fig. 2).

Coating thickness measurements, using small radio controlled probes
Difficult to access areas inside ships provide recesses for humidity. As these areas often are particularly crucial to safety, they are given special consideration when inspected during safety and final inspections, as in these areas especially the danger of to little coating being applied due to streaming conditions increases the risk of corrosion. Only gauges and measurement probes with low installation heights can be used in such difficult to access areas. An only thump-sized independent probe such as the radio-control probe QNix® 8500 sat is of special advantage in such difficult conditions: as, for example, a worker can even in such areas safely and accurately record his measurements almost completely free and unhindered (as shown in figure 3 and 4).

Ruby gauge heads guarantee lasting measurement precision
As usually several thousand measurements have to be recorded when measuring on large ships, rugged gauge heads are required because only the contact surface of an undamaged gauge head guarantees correct and accurate measurements. Therefore, special coating thickness gauge head contact surfaces with a ruby tip have proven to be the best choice for high quality gauges. The rubies hardness makes it one of the hardest materials after diamonds. Figure 5 shows the example of such a gauge head in which centre the ruby can clearly be recognized. Its robustness ensures productive measuring and reliable results even through out large projects.

Quality management: Statistics and documentation for a safe and structured data collection of large ship building projects
Modularly attachable probes allow measurement systems to be adjusted to any given measurement task. Furthermore, the availability of the separate system modules increases, as the measurement probes can be interchanged among the devices. In addition to the simple gauges without a statistics function for coating workers, gauges featuring such a function are required for general and final inspections of ships, as several thousand measurements have to be recorded during such inspections. A fast and structured measurement recording taken from each separate layer of the usually applied multi-layer systems, depending on location and time is essential (ref. to fig. 6) allowing for an effective operation, thus increasing cost-effectiveness of the quality management. Additionally particular evaluation procedures are necessary for the various measurements on large surfaces; with the special SSPC-PA2 procedure of the “Society for protective coatings” worth mentioning in particular [10].

The adjustment of the coating thickness gauges’ menu navigation to different languages allows for a fast and effective training of international staff members and the exchange of the devices even across language barriers. In addition to the convenient multi-language operation, the safety of all recorded measurements is of highest priority. The radio transmission of recorded measurements to a PC for statistical analysis and documentation with Microsoft Excel allows for fast and convenient work without dirtying the gauges plugs in the rough surrounding conditions avoiding related problems. Using the convenient and versatile spreadsheet program, a user can analyze the measuring data in a structured manner, print it or send it to project partners via an internet connection.

Quality by Excellence: Precision and robust reliability during everyday use
The new modular QNix® 8500 coating thickness measurement system is the measurement device of choice – providing flexible and individually interchangeable measurement probes, easiest operation and fast data transmission. The only thump-sized and 30 grams light radio-control probe of the QNix® 8500 paint gauge system allows precision measurements. Thanks to its extremely small dimensions it provides accuracy and high functionality even on measuring spots until now considered inaccessible but crucial to safety and under rough everyday conditions. Short repair and replacement times guarantee the particularly cost-efficient use of QNix® coating thickness devices worldwide.

In ship building especially the permanent and uninterrupted function of coating thickness measurement devices is of particular importance through out the complete works during the only short dry-dock times. Flexible systems with statistics function allowing printout via PC facilitate the quality management of executive coating companies in particular. The high quality of coating thickness measurement devices from AUTOMATION Dr Nix, exclusively manufactured in Germany, and the fast customer oriented service guarantee users world wide a high amount of productivity and an improvement of their benefit. Quality made in Germany pays off

Literature:
[ 1] J. K. Paik and A. K. Thayamballi
” Ultimate strength of ageing ships”
Proceedings of the Institution of Mechanical Engineers, Part M
Journal of Engineering for the Maritime Environment
Volume 216, Number 1 / 2002; pages 57-77
[ 2] W. Schwenk
“Prinzipien der Korrosion und des Korrosionsschutzes in Meerwasser“
Vorträge der Fachtagung „Meerwasser-Korrosion“
Schiffbautechnische Gesellschaft e.V. Hamburg
[ 3] Callow Maureen
“ Ship fouling. Problems and solutions“
Chemistry and Industry, no. 5, pp. 123-127. 1990
[ 4] Brady, R. F. Jr
“ Clean hulls without poisons: Divising and testing nontoxic marine coatings“
Journal of Coatings Technology (USA). Vol. 72, no. 900, pp. 45, 47-56. Jan. 2000
[ 5] DIN EN ISO 12944
“ Korrosionsschutz von Stahlbauten durch Beschichtungssysteme“
CEN Europäisches Komitee für Normung
International Organization for Standardization (ISO)
[ 6] ISO 8501-1
“Preparation of Substrates Before Application of Paints and Related Products- Visual Assessment of Surface “
International Organization for Standardization (ISO)
[ 7] ISO 8502
“Preparation of Substrates Before Applications of Paints and Related Products- Tests for Assessment of Surface Cleanliness: “
International Organization for Standardization (ISO)
[ 8] Resolution MSC.215(82) „Performance standard for protective coatings“ IMO Naval Architectural Group - Maritime Safety Committee (MSC)
[ 9] DIN EN ISO 2808 ” Paints and varnishes -- Determination of film thickness”
CEN Europäisches Komitee für Normung
International Organization for Standardization (ISO) (TC 35/SC 9)
[ 10] SSPC-PA 2
“Measurement of Dry Coating Thickness with magnetic Gages” SSPC: The Society for Protective Coatings

Figures:
Figure 1: Wet film measuring comb for determination of undried coating according to ISO2808

Figure 2: QNix® 8500 gauge for the non-destructive determination of coating thickness on metal such as steel according to ISO 2808 providing individual language adjustment and, if requested, measuring data analysis according to SSPC-PA2

Figure 3: Coating thickness measurement even at difficult to access measuring spots using small measuring probes (figure showing modular measurement system QNix® 8500 With radio-control probe Q-Nix® sat).

Figure 4: Convenient coating thickness inspections using radio based measuring data transmission (figure showing the modular measurement system QNix® 8500 with radio-controlled probe QNix® sat).

Figure 5: Measuring head of a coating thickness measuring probe with a ruby contact

Figure 6: methodical acquisition of coating thicknesses on a ship based on location and time

(For Information from TestCoat, Inc. Phone 717-334-3372 or mail us at sales@testcoat-usa.com).

Reference
Ealey, L. (1987, July). QFD Bad Name for a great system. Automotive Industries, CLXVII(7), 21.

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Gettysburg, PA 17325