Written by: Zygmunt Tyska
Hull bonding of laminate yachts
Yachts
With more and more sailing enthusiasts owning motor or sailing yachts, some even building their yacht “from scratch”, we would like to introduce you to the use of PLEXUS adhesives in yacht building. At sea, every sailor expects a boat he can rely on – durable and resistant to harsh conditions. Therefore, many boat and yacht building companies are inclined to use newer and newer technologies in their construction. PLEXUS adhesives fit perfectly into the manufacturers’ expectations.
Like road vehicles, yachts are subject to dynamic wave action. Vehicles are equipped with shock absorbers that reduce structural loads and improve ride comfort; in the case of yachts, this role is fulfilled by PLEXUS adhesives, which replace rigid joints in the yacht’s structure. The diagram below (Figure 1.) shows the shock-absorbing contribution of the adhesive in the hull structure.
The same amount of energy is absorbed in both constructions, but a yacht glued with PLEXUS adhesives is subjected to gentler loads, which has a positive effect on the comfort of sailing and increases the life of the yacht.
PLEXUS adhesives have the necessary certificates from regional classification societies.
PLEXUS adhesives in yacht bonding
PLEXUS offers a wide range of methacrylate adhesives, but only a few are suitable for bonding basic yacht components. Ideal for these purposes are those that have a relatively low modulus of elasticity and allow a large weld thickness. PLEXUS MA425 is most often used in the production of Polish yachts. However, in the case of larger yachts, the parameters of this adhesive may not be sufficient and another PLEXUS adhesive should be selected.
For the average amateur yachtsman, using PLEXUS adhesives for gluing yachts will bring the following advantages
- Improve the quality of the swim.
- Reduce the magnitude of loads, resulting in a reduction in the amount and size of damage.
- Increase fatigue strength.
- Extend the life of the yacht.
An example of the use of PLEXUS adhesive for bonding a yacht hull
The hull of the motor yacht shown in the photo (Fig. 2) was built at the GEMINI GROUP GDANSK shipyard.
A bottom insert weighing 1200 kg was bonded into the hull with a length of L=50′ (Figure 3). The adhesive used was PLEXUS MA557, which allowed for a 10-37 mm adhesive layer and a shelf life of 80-90 minutes.
Glue was applied using cone-shaped bags to flatten the liner to the desired width and thickness as it was pressed against the jacket, requiring the width, length and frequency of the applied glue rollers to be selected accordingly (Figure 4).
Bonding operations, including mixing the adhesive components, applying them to the surfaces to be bonded, and placing and pressing the insert, took 75 minutes, and bonding the deck to the side plating took even less time. Bonding significantly reduces the time required to join yacht components, and allows for the joining of inaccessible parts that would be impossible to join using lamination. If yachts were to be built on a larger scale, it would be possible to mechanize the application of glue, which would greatly improve the entire yacht production process.
Working safely with PLEXUS adhesives
In the course of any work, it is extremely important to follow health and safety rules. PLEXUS adhesives allow working in safe conditions – they emit minimal amounts of vapors harmful to human health. With proper organization of work, the maximum permissible concentrations (MPC) are not exceeded, and working in such conditions does not threaten the health and life of employees.
In the shipyard of GEMINI GROUP GDANSK, up to 170 kg of glue was used, and the working conditions were very good, the concentration of glue vapors was much lower than the permissible standards.
Advantages of PLEXUS Adhesives
- Preparation for bonding does not require special procedures.
- Production costs are reduced.
- Bonding significantly reduces the time required to join components.
- Joints are strong and durable.
- Allows simplification of construction.
- Improves worker health and safety.
Curiosity
There is a well known case from the now defunct VACE shipyard in Gdansk, Poland, where a yacht ran aground while in use and its hull was badly damaged, but the weld that connected the underwater part of the stainless steel hull to the upper part of the laminate hull was not damaged. PLEXUS MA550 adhesive was used to make this joint, and it turned out to be extremely strong and very good at bonding stainless steel to laminate.
Summary
PLEXUS adhesives are widely used in boatyards for bonding laminate yacht hulls. Thanks to their strength and resistance to harsh conditions, they provide solidity and safety during sailing. PLEXUS adhesives replace traditional rigid joints to absorb the impact of waves and improve sailing comfort. They also make yachts more durable and significantly extend their service life. An example of the use of PLEXUS adhesives is the bonding of the bottom liner to the yacht’s hull, which reduces the time required to join the components and provides strong, durable joints. They are extremely effective and meet the highest standards of yacht builders.
