Boatyard Vessel Work and Antifouling FAQ’s
Frequently Asked Questions on Vessel Work and Antifouling
In a typical year Cleanlift Marine will service and antifoul hundreds of vessels ranging from runabouts to the larger sail, motor yachts and commercial vessels. Our high level of repeat business gives us the ideal opportunity to undertake continual evaluation of our products and performance. Our experience has led us to the point where we feel we can offer the best possible advice to our customers.
- Estimation & Work Request
- Variations to Quote
- Why antifoul annually?
- One coat or two?
- Hard or ablative antifoul
- What is Propspeed?
- When should I Acid Wash?
- What is osmosis?
Quotation & Work Request
At our yard we take the hassle out of having your boat antifouled. We also understand you may have a budget for the maintenance of your boat and we will make every effort to accommodate you.
Once we have discussed exactly what you require, in most cases, we can offer an accurate estimate on pricing – though it is difficult to give a definite cost, without knowing what additional work may need doing, until that boat is out of the water.
Variations to an Estimate
From time to time, unexpected issues may arise and need attention, which can only be identified when your boat is out of the water. Even with the best efforts of the owner and boatyard staff, situations can arise that require extra labour or materials.
In this event, you will be contacted and invited to the boatyard, if possible, to discuss and decide for yourself the necessity of our recommendations. If you are unable to visit in person, an estimate of cost and photographic evidence can be provided to you for your approval.
In no circumstance will we proceed with any repairs or upgrades outside the original estimate, no matter how necessary, without your express consent.
To assist those customers with busy schedules, who may not be able to take the time off to deliver and collect their boat, we offer a towing service from her berth and back again.
Why antifoul annually?
Your boat is a significant investment. To protect your investment and provide reliable leisure time aboard, maintenance is the key.
There are antifoul paints that, depending on vessel usage and local environmental factors, can provide varying periods of satisfactory service, if you are prepared to pay the premium for the product. Notwithstanding, your boat still should be slipped at least every year to change her anodes, check propeller shaft bearings, rudder bearings and skin fittings.
Our advice is to haul your boat annually and carry out these inspections; apply a full coat of antifoul all over, with a manufacturer specified DFT of 75 microns, and a 2nd coat around the waterline, leading edges of the keel, rudder(s) and running gear. Year in year out, we find that this is the most cost effective programme for boat owners.
One coat or two?
What are the merits of applying two full coat of antifoul as against one?
Of course we will do whatever the customer requests, however our observations are that boats which receive two coats, in most cases, become just as fouled after 12 months as those which receive a single coat.
Antifoul by nature is very thick; it has various solids and resins that are designed to dissolve out of the paint during its life. This causes any remaining paint to be slightly “brittle” and weak in structure. Over years of antifoul build up, the old paint is prone to cracking or flaking and may simply fall off in patches. There comes a time when all old flaking antifoul needs to be removed, with an abrading process such as Abrasive Blasting or scrapping which may be delayed by annual slipping and one good coat of professionally applied antifoul.
Hard or ablative antifoul?
Both have their place and limitations, peculiar to each, but both generally provide 12 month service life. It is a personal preference of type and brand.
Ablative antifoul is softer and self polishes as the boat moves through the water. It works well if the boat is used regularly. For best results the vessel needs to be moving through the water for the ablating action to work effectively. not sitting on her mooring or berth for extended periods of time. Ablative antifouling will typically give a service life of 12 months, if the boat is used regularly. If the boat is not used regularly, we find the boat, especially the running gear, will be fouled within 8-10 months.
Hard antifouling can stand some scrubbing with a soft brush to remove the slime bacteria which precedes weed and mussel growth, without causing the toxins to be released into the water. It has similar lasting characteristics as ablative antifoulings.
If you wish to change antifouling types generally speaking ablative antifouling can be applied over hard antifouling, but if wishing to change from soft antifouling to a hard type it is recommended you either removal the coating or at least apply a primer coat to seal off the old antifoul prior to applying the paint of your choice.
What is Propspeed?
Propspeed is a relatively new innovation specifically designed for application on propellers, rudders, shafts, skegs and trim tabs. Propspeed works because it is slick, not because it is toxic.
Application of Propspeed is a two step process using a 2-part etch primer followed by a silicone based top coat. Propspeed is an environmentally safe product and does not contain copper, tin or any other toxic substance which may cause environmental pollution.
Propspeed will increase vessel performance, increase fuel efficiency and will provide a full 12 months of service. Its limitations are only if the vessel has an electrolysis issue, or coated surfaces come into contact with any abrasives such as a diver cleaning your hull or a sand bank.
Cleanlift Marine is an approved Propspeed Applicator.
When should I get an Acid Wash?
The gel coat on a GRP boat over time will oxidize, stain and loose its gloss. An acid wash when she is on the slip or hardstand is a cheap and easy way to remove the oxidization, brighten the colour and remove stains. It will not restore any shine whatsoever, for that you will need to have the vessel machine polished (see Polishing below).
All boats time can get a brown “moustache” where the water pushed up from the bow wave is constantly washing past the hull. The acid wash process will remove this stain without scratching or causing any damage to the gelcoat. Your boat will look much cleaner and brighter.
Machine polishing is highly recommended to protect your boat from the salt and sun by introducing a wax layer to the surface. Newer boats that are polished will retain their gloss much longer with regular polishing. They will stay looking new and help add value upon re-sale against a similar boat that has not been polished.
Older boats are more difficult to bring a shine to, though with an acid wash and a good machine buff, you will certainly notice the difference, even if you do not achieve the “as new” shine. For older boats it is a longer process and the machine buffing provides a good platform to build upon; the more you polish during your regular maintenance days, the better she will become.
What is Osmosis?
Osmosis occurs when moisture is drawn through the underwater gelcoat or laminate to an air void in the fibreglass lay–up. Over time it continues to draw moisture and ultimately forms an osmotic blister.
How is it identified?
Osmosis is initially recognized as small blistering on the underwater surface of a GRP vessel.
How is it caused?
However hard or well cured they may be all polyester gelcoats, even those laid down to down to the best commercial practices, represent “semi permeable” membranes! This is a biological term which, in abbreviated terms, means that they allow a proportion of water molecules to pass through into the laminate when the vessel is immersed, a sort of “molecular wave” Improved polyester resins have been developed together with vinylester resins; they offer added resistance to osmosis and should remain blister free for a longer period of time.
Which vessels get it?
It is estimated that about 40% of all GRP hulls, with no initial protection, show symptoms of osmotic blistering within 5 years, and as much as 80% after 10 years. This information applies to vessels permanently immersed.
How can it be repaired?
The extent of the osmosis is often the reason to justify the cost of repairs.
Initially before treatment can begin the blisters need to be exposed. This is best achieved by strip planning or abrasive blasting. Once all the “osmosis damage” has been exposed, the vessel is left to “dry out” with periodic washing down to remove the acidic moisture exuded from the surface.
Once acceptable moisture meter readings are recorded repairs can begin. The damaged area is sanded and coated with epoxy resin. This may be followed by a glass layup if deemed necessary. All voids are filled with epoxy filler, then, the area is resanded and refilled. A final sand and another application of epoxy resin coating followed by multiple coats of epoxy high build primer. The area is then prepared for the coatings of antifouling.
The end result provides the desired hard, waterproof barrier between the layup and the sea water. This process will protect the vessel from further osmosis activity for a considerable period of time. The duration of the repairs is dependent of the time the hull takes to «dry out”