BOWTHRUSTER INSTALLATION

Problem:

Manage and oversee installation of a bowthruster on an aluminium sailing yacht. This kind of installation requires, next to dry-docking in a suitable environment, a shop, which can coordinate engineering work, metal and electrical work, as well as some paint work.

Steps for Installing the Bowthruster:

1. Recommend suitable bowthruster and installation details.
2. Determine suitable shop and dry-docking environment. Receive and evaluate quotes and time-schedule.
3. Have the yacht haul out to dry-dock.
4. Identify exact location for the bowthruster tube. Consult criteria in the thruster’s installation manual and determine conditions of the hull.
5. Check carefully for the  correct orientation of the bowthruster tube.
6. Mark the hole on the hull. A special cutting compass can be used both for marking and for cutting/ milling the hole perimeter. Smoothen hole edges.
7. Machine tube to required diameter. Place tube into the bowthruster bore. Mark tube’s cutting line and machine aperture for the thruster leg. Consult manual.
8. Remove tube and cut to lengths. Consider that around the tube the hull will have to be shaped. Consult manual.
9. Carefully weld tube into the bore. First tack and then weld around. Inert gas welding is required.
10. Sand or grit blast exposed bare metal and prime.
11. Install  bowthruster motor and leg, wire electrical connections. Carefully test system on hard.
12. Model shapers around the thruster with epoxy filler.
13. Apply antifouling.
14. Launch vessel, carry out seatrials, hand over vessel.

Contact us for your custom management needs.

REPAIR of BALSA and CORE OSMOSIS

Problem:

The owner of the Contest sailing yacht contacted marineSOLUTIONS because of a broken starboard rubrail and two blisters greater than 10 cm in diameter that had appeared on the hull. These bubbles were about 15mm thick. Two wet water marks running down the side were apparent. When the blisters were opened during our inspection, they were found to contain liquid with a pH in the aceitic range. Salt seawater that is trapped between polyester layers may cause hydrolysis, or as it is also known, osmosis.The well-known tell tale signs of osmosis: are blisters filled with liquid that smells like vinegar. We determined that this liquid was coming from the balsa core and had entered via the delamination on the starboard rubrail.

Procedure:

Repair work would entail a drying out period of at least 4 months. The yacht was first hauled to dry-dock. The paint and epoxy were removed from the necessary areas on the starboard side using our gel plane machine, which exposed the outer layer of the balsa sandwich, and the boat was left to dry out naturally.

Work step 1:

A few balsa samples were taken from a small area on the starboard side of the hull and examined for rot.

Work step 2:

The designer of the yacht was contacted and the problem was explained to him. Information was obtained about the structural details of the balsa and upper layers (paint, filler, thicknesses of balsa etc.)

Work step 3:

The entire area affected by water was cleaned of paint and filler to expose the uppermost layer of the sandwich.

Work step 4:

The sandwich was allowed to dry naturally, and the level of moisture was checked regularly.

Work step 5:

When the moisture had decreased to acceptable levels, the upper layer of the balsa was impregnated with an antifungicide.

Work step 6:

The whole of the exposed area was covered with a coat of epoxy and fibreglass to give reinforcement.

Work step 7:

After this, baxial fibre was applied to the layers that would provide the necessary reinforcement in connection with the boat’s structure.

Work step 8:

The glassed surfaces were covered with epoxy filler, levelled with a gauge and sanded smooth by longboarding.

Work step 9:

The areas that had been repaired were sprayed with gel coat to match the original colour, and the surface was faired and polished.

Work step 10:

Layers of waterproofing epoxy were applied to the hull below the waterline to protect this area.

Work step 11:

The boat topline was painted with two good coats of paint in its original colour.

Work step 12:

Three coats of selfpolishing antifouling paint were applied.

Work step 13:

The yacht was launched and handed over to the owner.

KEEL REPAIRING

Problem:

A 49-foot Jeanneau Sun Odyssey sailing yacht hit rocks with the front edge of her keel while sailing at a speed of 4 knots. The keel was damaged on the lower front section and underneath, and the boat began taking on a little water through the keel.

Procedure:

After the yacht owner had obtained the necessary approval from the insurance company, he contacted yachtWORKS and requested that the boat be transferred from Ayvalik to our centre in Turgutreis for repair.

Work step 1:

The stages and costs of the repairs were determined. The yacht owner informed the insurance company of the repair costs and received their approval.

Work step 2:

A repair team and sailing crew were sent to Ayvalik to bring the boat via the sea route. Having made temporary repairs to the boat, our team sailed it to D-Marin where the keel would be removed and repaired.

Work step 3:

The yacht was dry-docked as soon as she arrived at D-Marin, her hull below the waterline was pressure-washed and then examined carefully.

Work step 4:

There was a tear on the underside of the keel and the coating had been scraped off, there was separation between the keel and the hull, and cracks in the hull as a result of the separation of the keel connecting plate.

Work step 5:

The keel was removed from the hull. The section of the hull that joins to the keel was opened up and reinforced with epoxy and fibre. It was then sanded smooth, filler was applied and the area was sanded again. An epoxy primer was then applied, followed by antifouling paint.

Work step 6:

The paint and filler on the damaged section at the bottom of the keel were removed and the metal was cleaned. Following application of protective paint; epoxy filler, epoxy undercoat and antifouling paint were applied.

Work step 7:

Meanwhile, each of the keel bolts was individually inspected, and damaged bolts were replaced with new ones produced in our lathe workshop.

Work step 8:

While these procedures were being carried out on the exterior, on the inside of the boat, the cracks around the keel connection were repaired as follows: the cracks were opened up and filled with epoxy and fibreglass, then covered with filler, sanded to a smooth finish and painted.

Work step 9:

The keel connection plate was repaired and straightened in a press.

Work step 10:

The yacht was put on a lift for the remounting of the keel. This very delicate operation was carried out with great care and was successful. Sikaflex, an elastic glue used for its anti-leak and bonding properties, was applied liberally to the whole of the top of the keel. After the keel had been put in place, while the bolts connecting it to the hull were being tightened on the inside, excess Sikaflex from between the hull and the keel was cleaned away on the exterior.

Work step 11:

After the final coat of antifouling paint, the yacht was launched, and handed over to the owner.

Comment of the customer:

“As promised, marineSOLUTIONS did a very professional job and completed the work on time. The firm’s knowledge of their subject and experience ensured that everything went smoothly. I am thoroughly satisfied with marineSOLUTIONS’ service and will definitely use them again in the future.”