Adhesives, marine applications

There is a need for an accurate assessment of the mechanism of cathodic debonding of thick adherends. This would contribute to better control over the selection of formulations resistant to attack. One of the objectives of this work was to develop an accelerated screening test. The screening test was used to evaluate the relative performance profiles of a number of commercial adhesives which were recommended for marine applications. It is hoped that a screening test such as this one could be used to isolate measurable primer properties which can be related to the long term prospectus of the primer, and the variability of this prospectus under permutation of substrate type or additives. 

Much of the focus of the following work was aimed at the previously mentioned Chemlok adhesive system. This was because it had been used extensively in a familiar marine application, we were acquainted with its long term performance so it could be used as a baseline for comparison with other commercial adhesive formulations. All of the commercial adhesives used, including Chemlok 205/220, are proprietary formulations, thus the exact functional nature of each adhesive is not available. 

To further understand the action of the hydroxide ions on the primer properties, weight gain tests were undertaken on various, commercially available adhesives. We attempted to prepare neat samples of ten types of adhesive agents (ie top coats and primers) which had been recommended by the manufacturers as suitable for marine applications. The neat samples were prepared with the use of a commercial adjustable wet film applicator supplied by the Paul Gardner Company. This applicator will lay films up to 0.25inches... 

At least one conclusion can be drawn from all of this. Primers that experience large increases in swelling in the presence of hydroxide ion, despite stability and considerable bond strength in salt water, would probably perform poorly if a cathodic potential was applied. Thus, the qualification of an adhesive system for a marine application that includes exposure of the metal substrate to a cathodic potential, should Include examination of the... 

Fillers with a density lower than that of epoxy can be used to provide reduced specific gravity in cured products. These are usually gas-filled microballoons. Although they generally bring about a significant increase in viscosity, the microballoon filled epoxies (sometimes called syntactic foam adhesives) are often used in marine applications where low density and buoyancy are important criteria. 

Adhesives for Structural and Engineering Applications, C. O Reilly, Loctite (Ireland) Ltd. Polymers in Marine Applications, C.F.Britton, Corrosion Monitoring Consultancy. 

Conventional calcium greases have good adhesive properties and they are extremely water resistant. At relatively low cost, their use today continues in cool, wet conditions such as in marine applications, propeller housings and water pumps. 

A unfilled, highly thixotropic paste, urethane acrylate flexible adhesive for shock absorbing and impact absorbing structural fillets. Bonds FRP and a wide range of substrates. Accepted by Lloyd s and Det Norske Veritas, for marine application. 

A thixotropic low density core bonding adhesive paste designed to bond primed balsa and PVC cores in sandwich constructions. Accepted by Lloyd s for marine application. 

Typical Use Marine applications. General purpose adhesive for the Typical Use Construction. Wall-panelling and stiffeners. Steel, wood, ... 

Sikaflex -291 One-component, polyurethane-based sealing/adhesive compound All-purpose grade is used for general marine adhesive sealing applications Low viscous, medium modulus. 

However, due to the considerable commercial pressure by the aluminium companies, many aeroplanes, by that time, were essentially wooden aircraft built out of metal . The use of U/F glues, therefore, was initially confined to marine applications. With the outbreak of the Second World War and the potential shortages envisaged for aluminium, the industry turned back to the use of wood and to U/F adhesives. 

Although they were patented in 1930, resorcinol-formaldehyde (R/F) adhesives, based on resorcinol novolac resins, started to appear in the mid- to late 1940s, following the discovery of how to control flieir reactivity by ensuring that their pH was close to, or just slightly above, neutral. However, their formulation is somewhat complex and the pure R/F systems have, essentially, only been used in marine applications. However, there is an exception as these systems do stUl have one application in the aircraft industry. They are used in wooden propeller... 

University of Glasgow (M Cowling - adhesive bonding of ship-related structures, S Hashim - bonding of composites including marine applications)... 

This section will first present the particularities of adhesive bonding for this industry. There are a number of specific marine requirements, resulting from regulatory requirements, the way marine structures are assembled, and the environment they meet in service. Thus, when considering adhesive bonding of structures for marine applications, in comparison with other industrial applications, the following points need particular attention ... 

Polymers maybe sensitive to all these environmental factors, and particularly to water and temperature. In addition, the influence of different parameters such as mechanical loading and water diffusion are known to be coupled mechanical loads accelerate water ingress and water affects the stresses developed in a joint. Adhesive formulation for marine applications is therefore critical but, as will be discussed in more detail below, it is not yet possible to fiilly predict long-term marine performance of adhesive assemblies. Appropriate testing is therefore again essential to guarantee satisfactory performance. 

There is a vast literature on surface preparation for adhesive bonding and readers will find detailed discussions both elsewhere in this volume and in various reference books (Kinloch 1987 Adams 2005). Here, only some aspects specific to marine applications and the marine environment will be discussed. Modern boat structures are generally composite, mainly for... 

In most cases in boatyards only steps (2) and (5) are used, but for many marine applications peel plies are used to protect the surface of molded parts before bonding. These are fine polyester or nylon fabric layers, which are placed over the region to be bonded, O Fig. 48.12. The peel ply is peeled off just before the adhesive is applied, to reveal a clean,... 

Davies P, Baley C, Loaec H, Grohens Y (2005) Interlaminar tests for marine applications. Evaluation of the influence of peel plies and fabrication delays. Appl Compos Materials 12(5) 293-307 Diez de Ulzumin 1, Lopez F, Herreros MA, Suarez JC (2007) Tests of deck-to-huU adhesive joints in GFRP boats. Eng Fail Anal 14(2) 310-320 DNV (Det Norske Veritas) Standard for Certification, No. 2.9, Type Approval Programme No. 1-501.12, Adhesives, October 2009... 

Pressure sensitive adhesives and adhesive-coated articles have found a growing list of applications in the automotive, marine, airplane and appliance industries. The main uses are in assembly and decoration, but applications in the areas of... 

About 8,000 metric tons of peroxides were consumed in 1972. This consumption was strongly stimulated by the rapid growth in reinforced plastics (Ref 23). The largest volume product is benzoyl peroxide which is used in polystyrene and polyester markets for such items as toys, automobiles, furniture, marine, transportation and mil requirements. Also, methyl ethyl ketone peroxide is used in large volumes to cure (as a catalyst) styrene-unsatur-ated polyester adhesive resins used in mil ammo adhesive applications, as well as in glass fiber reinforced plastic products such as boats, shower stalls, tub components, automobile bodies, sports equipment, etc. The monoperesters are growing slowly because of some substitution of the peroxydicarbonates and azo compds (Refs 8,9 23)... 

Marine coatings Organic coatings for corrosion control Paint acrylic ester polymers, 7 388-389 adhesion, 7 90-92 advanced ceramic, 7 704-705 alkanolamines from olefin oxides and ammonia, 2 136 alkyd resins, 2.T67-168 amino acid resin applications, 2 635—637 anticorrosion, 25 134 anticorrosion metallic, 7 713-714... 

Other applications for phenolics are switchgears, handles, and appliance parts, such as washing machine agitators (that s why they re usually black). Phenolics are widely used to bond plywood, particularly exterior and marine grades. Although urea-formaldehyde resins are cheaper for this purpose, they were not nearly as water-resistant and have been limited to interior grades. Abrasive wheels and brake linings also are bonded with phenolic adhesives. 

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