HOCHLEITNER - INSIGHTS , Marine - Industrial

How to rescue the world's biggest cargo ships

Sun, 05 Jun 2022 17:48:24 +0000

Container ships ferry goods all over the world, but when one of them gets into trouble – as happened with the Ever Given and Ever Forward recently – how can they be saved?

The world's cargo ships, which transport around 90% of global trade, do not always make it to their destination without incident. According to the Safety and Shipping Review by insurance company Allianz, 27 cargo vessels were lost in major incidents during 2021, and 357 during the past decade. They catch fire. They hit rocks, reefs and sand bars. They malfunction. But they don't always sink. Whenever there's a chance to rescue a large ship, their owners almost always take it because these vessels can be worth hundreds of millions of dollars.

How to rehabilitate old oil supertankers

Sun, 05 Jun 2022 17:48:24 +0000

Supertankers are carrying 3.8 b illion barrels of crude oil among them, enough to fuel around 418,000 transatlantic flights and for the world’s cars to cover around 3 billion miles between them. Their sticky cargo is the raw material for billions of plastic bags, combs, trainers, drinking straws, synthetic clothing, toys, water bottles and hundreds of other plastic-based goods that we use in our daily lives. But can they be transformed to be good for the environment?

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Development of Anti-fouling Coating Using in Marine Environment

Wed, 18 May 2022 22:58:00 +0000

Chen Liu. Development of Anti-fouling Coating Using in Marine Environment. International Journal of Environmental Monitoring

The marine organism attaching to the ship hull would slow down the ship and increasing fuel consumption. In order to prevent the problem, anti-fouling paints are used to coat the bottoms of ships. At the same time, the harmful environmental effects of these paints such as tributyltin have been recognized. The International Convention on the Control of Harmful Anti-fouling Systems on Ships was adopted by the IMO in 2001 to prohibit the use of harmful organotins in anti-fouling paints used on ships. As the invention entered into force internationally, the most important work is to develop new material to replace the traditional coating. In this work, we summarize the development of anti-fouling paints all over the world and introduce the progress of the latest research.

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MARINE BIOFOULING TESTING

Wed, 18 May 2022 22:58:00 +0000

MARINE BIOFOULING TESTING:TECHNICAL CONSIDERATIONS ON METHODS,SITE SELECTION AND DYNAMIC TESTS

There is need to optimize testing protocols for marine coatings and develop improved accelerated test systems that best simulate the erosion process on marine paints as ships travel. The selection of a marine environment with aggressive biofouling conditions is necessary to obtain early results on the performance of experimental antifouling coatings. Simulation of the erosion of the coatings on the hull is an important tool in evaluating the efficacy of novel formulations.
Procedures in marine exposure testing, criteria in the selection of ideal sites with aggressive fouling conditions and a proposal for a modified dynamic test system are described.

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Influence of Paint on Steel Corrosion for Marine Applications

Tue, 03 May 2022 22:50:00 +0000

Department of Production Engineering and Printing Technology, Akhbar El-Yom Academy Abdou Abdel-Samad1*, Yaser Soud, M. Zaki

The majority of naval ships are constructed of mild steel. Corrosion is a major concern in a maritime environment. This particular type of material degradation has recently received more attention by the marine industry. The present work aims to investigate the effect of recent coatings used in marine ship surfaces for preventing corrosion. Experiments were performed according to standard tests to evaluate and measure the coating adhesion to steel and to measure the corrosion wear rate if any for three types of coatings.

An accelerated corrosion test was conducted to duplicate in the laboratory the field corrosion performance of a product. The results indicate that all tested types of paint have resulted in a reduction in the corrosion rate compared with the uncoated steel.

A minimum corrosion rate of 0.8 mm/year for the coat “Hempadur 52,140” was obtained compared to 2.1 mm/year for the uncoated steel. A microscopic examination of the corroded steel surfaces was conducted which prevailed pitting behavior with different degree.

The minimum corroded surface exhibited few pitting attack in comparison to other specimens. Although the pitting attack of the surface layer (paint), one can drive a conclusion that sample surface without coating is aggressively attacked by pits.
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Surface Preparation is the most important part of a coating system - Series Part 2

Wed, 20 Apr 2022 19:08:00 +0000

The coatings inspector is the one ultimately responsible for ensuring that the specified degree of surface cleanliness is actually achieved.

Coatings experts often say that surface preparation is the most important part of a coating system.

Effective surface preparation is of paramount importance to the success and longevity of a coating system.

Surface preparation affects the performance of the coating more than any other variable. Given that the proper coating system has been selected, if the surface preparation is poor, coating performance is usually going to be poor.

If surface preparation is good, then the coating applied over it is likely to perform well.

For you, the applicator, it is useful to know the reasons why surface preparation is so important, because knowing why can help you to do a better job.

Surface Preparation Is a Foundation

First, we can express the reason for the importance of surface preparation in a broad, general way, with the help of an analogy or comparison.

Surface preparation is to a coating system what a foundation is to a building. If a building has a poor foundation it can collapse altogether.

If a coating system has a poor foundation / surface preparation), it will fail faster than expected (say, after 5 years rather than 10 years); or it can fail catastrophically, within the first year of application.

Both reduced service life and catastrophic failure, great financial losses occur to a facility owner.

The contractor may be held responsible for these losses if the surface preparation work is found to be faulty.

Surface preparation creates a foundation in 2 important ways: mechanically, by providing an anchor for the coating (adhesion-surface area) ; and chemically, by allowing intimate contact of coating molecules with the steel surface (bonding).

An inspector is likely to examine in the inspection of a coatings project following.

Scrutinize accurately the specification to make firm

1 the standard against which the work is to be measured;

2 the required level of surface cleanliness;

3 the maximum allowable surface profile;

4 special tests that may be required in the contract.

Identify the area being tested and

1 ensure that it is correctly identified in the daily inspection report and

2 ensure that the daily inspection report matches with the progress chart.

Inspect the pre-surface preparation condition of the steel to ensure that the requirements of the specification will be achieved.

Prior to blast cleaning, confirm that:

1 the surfaces are free from oil and grease;

2 the abrasive to be used is suitable and that it is recorded in the daily inspection report;

3 sieve analysis has been carried out, if necessary;

4 the abrasive is free from contamination, especially in cases of shop preparation where recycled media are used.

Beyond the obvious requirement that the abrasive should produce a clean steel surface that is free from contamination, it also should provide an adequate surface profile, a working mix of particle sizes, and particles only within the grading required.

Information should be obtained from datasheets about chemical analysis, hardness, density, chloride content, and conductivity. Conformity of the product to national or international safety regulations is typically indicated as well.

Carry out inspection of the prepared surfaces as necessary and when requested by the coating contractor’s supervisory staff to ensure that:

1 the specified standard has been achieved;

2 the surface profile is not exceeded or inadequate.

3 Overcoming the Negative of Debris

4 Non Visible Contaminants removed

Carry out, when necessary, special tests (e.g., soluble salt, rogue peaks, etc.) required by the specification.

1 Overwhelming the adverse of dirt; dust; grease; oil; rust; moisture; and, in some cases, mill scale.

2 Overwhelming the adverse of Non Visible chemical Contaminants

The most dangerous forms of Non Visible contaminants are soluble salts: chlorides and sulfates.

When chlorides and sulfates are painted over, they are hygroscopic and draw moisture to cause detachment, blistering, and enhanced corrosion of the steel substrate lying beneath .

Blistering caused by underfilm corrosion is a more gradual process, taking many months to appear, but the presence of conductive salts under the paint film and/or in corrosion products will greatly accelerate this.

It is prudent to examine for the presence of soluble salts with approved field test kits before paint application and then to apply further cleaning stages for salts purging, if they are present in negative amounts.

Certain projects conductivity/soluble salt contamination testing is mandatory.

The results of osmotic blistering salt contamination has a significant effect on coating performance and it is critical that monitoring of salt levels on the substrate is undertaken in Cargo, Water Ballast, Potable and Grey Water tanks .

The International Maritime Organisation “Performance Standard for Coatings (PSPC) for Dedicated Sea Water Ballast Tanks in All Types of Ships and Double-side Skin Spaces of Bulk Carriers” specifies a maximum allowable water soluble salt substrate contamination level of 50mg/m2 (5 micrograms/cm2) expressed as Sodium Chloride.

Adhesion is a primary function of paint.

Wet and dry adhesion of a coating system are two very different things with adhesion being significantly decreased in immersed conditions.

Contamination and adhesion, depend exclusively on the method used to prepare the substrate before coating application.

Surface defects unnoticed for normal service, can quickly result in coating failure when painting tanks.

Delamination on an artificial scribe after salt spray exposure should be considered as a one of a set of measurable factors representative of the corrosion protection performance of coatings.

It is absolutely necessary that for immersed environments the highest standard of preparation is achieved, this is the reason Sa 2 ½ blast, or equivalent, is normally required for such applications.

Record the results of the inspection, confirming that the areas inspected may be recognized from the reports.

Where remedial work is necessary, make sure that:

1 the areas are appropriately marked up so that the contractor’s supervisor can recognize them;

2 the supervisor and workers are aware of any reasons for rejecting the work and the requirements for further work;

3 the contractor’s supervisor is informed in writing of remedial work; and

4 the area under preparation is rechecked to make certain that it meets the requisite standards.

·Measure and record the surface profile using the appropriate standard method.

·Ensure that the prepared surface is coated within the maximum over-coating intervals. Over-coating interval related problems are more likely to occur with coatings which cure by cross linking, such as epoxies or polyurethanes.

·Inspect the steel prepared surfaces and ensure that the specified standards have been achieved prior paint application

When the specification calls for surface preparation by mechanical cleaning methods, in addition to the above inspection requirements, it will be necessary to confirm that:

1 excessive burnishing of the metal is avoided; Polishing of actual steel surfaces may also be a problem if brushing is carried out over zealously, because smooth polished surfaces can be detrimental to coating adhesion and

2 any visible peaks produced by power tool cleaning methods are removed. If this type of surface is painted without further preparation, the rough peaks can protrude through the coating and cause rash rusting and coating failure

Surface Preparation and Painting Process Standards - Series Part 7

Thu, 24 Mar 2022 20:00:00 +0000

The company should provide the coatings inspector with the most appropriate European standards relevant to the general activities in the surface preparation and painting process.

The Coatings Inspector job is to inspect the prepared surfaces, advise on whether the specified standards have been achieved, and then to accept or reject them as suitable for painting.

Following is a limited range of relevant standards:

SURFACE PREPARATION STANDARD BOOKS that are in common use in the shipbuilding and repair industry.

They are as follows:-

STANDARD ISO 8501 Corrosion Protection of Steel Structures by Painting

This standard is divided into 4 parts.

ISO 8501-1:2007 - Rust grades and preparation of uncoated steel substrates and steel substrates after overall removal of previous coatings.

ISO 8501-2:2001 - Preparation grades of previously coated steel substrates after localised removal of previous coatings.

ISO 8501-3:2007 - Preparation grades of welds, edges and other areas with surface imperfections.

ISO 8501-4:2006 - Initial surface conditions, preparation grades and flash rust grades in connection with high pressure water jetting.

• ISO 8502 series—Tests for the assessment of surface cleanliness.

Covers field methods for sampling moisture, dust, and chemical products and contaminants;

• ISO 8503 series—Surface characteristics of blast cleaned steel;

• ISO 8504 series—Methods for surface preparation;

ISO 1124-1127Abrasives Standards

• ISO 11124 series—Specification Metallic blast-cleaning abrasives;

• ISO 11125 series—Test methods for metallic blast-cleaning abrasives;

• ISO 11126 series— Specification Non Metallic blast-cleaning abrasives;

• ISO 11127 series—Test methods for non-metallic blast-cleaning abrasives; (Note that although some of these standards have been replaced, they may still be referenced in customer specifications, usually with the comment “or latest revision.”)

ISO 4628, Part 1Rating of Paint Defects

The ISO standard is called "Evaluation of Degradation of Paint Coatings—Designation of Intensity, Quantity and Size of Common Types of Defects. General Principles and Rating Schemes."

ISO 4628, Part 2Degree of blistering

ISO 4628, Part 3Degree of rusting

ISO 4628, Part 4Degree of cracking

ISO 4628, Part 5Degree of flaking

ISO 4628, Part 6Degree of chalking

Specific tests (i.e., adhesion pull-off ISO 4624 , cross-hatch ISO 8780-5 & ISO 787/16, paint film thickness ISO 2178 ,ISO 2808-6Aa & ISO 19840 and Measuring Dry Film Coating Thickness According to SSPC-PA2 for PSPC, holiday detection on painted surfaces ISO 2746, (etc.) are covered in ISO standards.

If specified in the customer’s specifications, these standards should be provided by the company when required.

The PSPC denotes to SSPC-PA2 when film thicknesses measurements are stated.
One important aspect of SSPC-PA2 is that it requires readings to be taken on the bare substrate, prior to any paint being applied, since surface varies from point to point as a result of blast-cleaning.
This methodology is designed to provide a consistent way of assessing coating thickness.
The readings are then corrected to allow for the profile / rough surface on the steel.

In addition to previously issued standards for solvent cleaning, hand and power-tool cleaning, abrasive blast cleaning, water-jetting, coating materials, paint and coating application, and related topics, there are new, revised, and recently issued documents for the following topics.

• Wet abrasive blast cleaning, industrial blast cleaning, and chemical stripping

• Newly manufactured, re-manufactured, and recycled metallic abrasives

• Surface preparation and coating of concrete

• Containment of debris generated during coating removal operations

• Sampling of environmental air, soil, and water during coating removal operations

• Application of thermal spray coatings (Metal Coatings)

• Shop, field, and maintenance painting of steel

In addition

• Primary Surface Preparation and Shop Primer Application

• Newbuildings

The International Maritime Organisation (IMO) Performance Standard for Protective Coatings (PSPC) for Dedicated Sea Water Ballast Tanks In All Types of Ships and Double-side Skin Spaces of Bulk Carriers

IACS have indicated that use of the standards will be mandatory under their Common Structural Rules.

Consequently the coating inspector needs to be familiar with these standards.

Marine paint fomulations: Conducting polymers as anticorrosive additives

Wed, 09 Mar 2022 22:31:00 +0000

Elaine Armelin, Ramón Oliver, Francisco Liesa, José I. Iribarren, Francesc Estrany, Carlos Alemán

Abstract

Within coating technology, there is increasing interest in the development of efficient anticorrosive additives able to replace the conventional inorganic anticorrosive pigments usually added to paints, which may have detrimental effects on both environment and health. A number of recent studies have evidenced that the modification of a paint formulation by the addition of a low concentration of conducting polymer (0.2–0.3%, w/w) increases significantly the protective properties of the coating. Here we focus on the principles of anticorrosive additives based on conducting polymers for marine paints. The article reviews the most important findings achieved in recent studies. The relevant factors that are determinant for the anticorrosive protection imparted by conducting polymers, as the doping level, the miscibility with paint, the electrochemical stability, etc., are discussed in detail.

Innovative paint solution to help protect ships from marine biofouling

Tue, 08 Mar 2022 22:41:00 +0000

European researchers have pioneered an ecologically friendly and sustainable antifouling paint solution that is based neither on biocide emission nor low adhesion.

The EU-funded Low Emission Antifouling (LEAF) project has developed an environmentally- friendly and fully sustainable prototype paint to minimise the damage to cruising ships and static constructions from marine biofouling.

The presence of micro and macroscopic fouling organisms, such as barnacles, on a ship's hull can become a major challenge for seafarers. As they multiply, they build up calcium deposits under a boat's paint, which in turn interferes with smooth fluid flow and can decrease fuel efficiency by up to 40 %, as well as result in higher carbon emissions. This is a major problem in particular for larger vessels and marine constructions.

Traditionally, a biocide-based poison, such as copper oxide, has been applied to hull paint to kill any fouling organisms attached, with 90 % of the world's marine fleet being coated in such a copper-based antifouling system.

However, coating a ship's hull in such a substance significantly increases the risk of toxins being released into the surrounding water, killing other marine life. Additionally, low adhesion coatings suffer from drawbacks of low durability and associated high material and maintenance costs.

In order to significantly reduce ecological damage and provide a solution that is both sustainable and cost-efficient, the innovative approach taken by the LEAF project does not rely on the exposure and release of biocides into the water.

Instead, the prototype paint's antifouling effect is based on the direct contact of a fouling organism with biocide that resides within the coating itself. This will also have the additional benefit of providing longer service life and fewer maintenance costs.

Promising tests held across European waters

After less than three years of development and testing in both the lab and in the field, the LEAF project has recorded successful results over the sustainability and durability of the prototype paint. Highly promising tests have been conducted in Scandinavian, Mediterranean and Caribbean waters.

During a test that took place in Grado's Lagoon, Italy, the hull of a boat that had been launched two and a half months earlier was fully colonised by tubeworms, indicating a high fouling pressure. Additionally, the white paint on the engine anchoring structures was suffering from significant marine biofouling.

Following the application of the prototype LEAF paint, in the same warm waters of the lagoon, the result three weeks later showed that the boat had a high level of antifouling efficacy. The boat owner also confirmed that the LEAF paint performed substantially better than the commercial products that had been used in previous seasons.

Additionally, human exposure and aquatic risk assessments performed within the project have shown that the LEAF paint is likely to comply with the most stringent global regulation systems, such as the European Biocidal Products Regulation (BPR).

The LEAF team is now currently working with external partners on the next steps required to fully commercialise the new technology and successfully bring it to market for all interested end-users.

What is fouling

Sat, 26 Feb 2022 15:15:00 +0000

According to Marine Paint research, is defined as: A particular species adhering to and growing on a hull depends on the waters through which the vessel moves, the season, and how much time the vessel spends in port.
Bacteria, cyanobacteria, diatoms (unicellular algae), and protozoans (unicellular animals) are common species in the initial microfouling. Diatoms excrete large quantities of extracellular polymeric substances (EPS), which contribute to the sliminess of the surface.

Following the microfouling, a macrofouling community establishes itself, consisting of soft or hard foulers. Soft foulers include higher algae, such as the green algae Ulva intestinalis. Ulva releases spores which, on touching a surface, secrete an adhesive consisting of glycoproteins to ensure that the algae adhere to and grow on the surface. Other types of soft foulers are sea squirts, sea anemones or soft corals. Hard foulers include mussels, tubeworms and barnacles, all of which have highly developed abilities to adhere strongly to the surface.

Different types of chemical adhesives, all have the same function; to allow the species to attach itself strongly to the surface.
Consequently, the fouling on a ship’s hull becomes a unique ecosystem in itself, but one that creates major problems for both commercial shipping and leisure boating.
The legislative pressure to develop antifouling strategies with low environmental impact, has led to a substantial commitment from national and international authorities.

The International Maritime Organisation (IMO), agreed in 2001 on a convention to ban of tributyltin (TBT)-based paints, as it has been shown to have severe ecotoxicological effects.

As of 2003, it is forbidden to apply new TBT-containing coatings, and from 2008 there is a ban on the presence of such paints on ship hulls for those states that adhere to the convention.

55 states representing 78% of the world tonnage

When developing new antifouling agents it is of the utmost importance to rigorously anticipate and assess the risk of long-term effects on the environment.