Prevention of Fouling

INTRODUCTION

“Fouling” is the term used to describe the growth of marine plant and animal life on structures, boats etc.  They consist of several specific types, including barnacles, amphipods, weed, slime etc. 

The negative effects of such growths include:

• Reduction of boat’s speed
• Increase of fuel consumption
• Structural damage, breakage
• “Marking”

To restrict the growth of fouling organisms, Antifouling Coatings can be used.  However, the amount of fouling varies not only from season to season but also from coast to coast, from river to river, from lake to lake, from harbour to harbour, even berth to berth.  There is also variation in the type of fouling as well as the amount.  It is not uncommon to find one side of a boat more fouled than the other.  Teamac Antifoulings are designed to be durable, to protect the structure, to be effective in defending against fouling and to be simple to use.  The whole range is fully H.S.E. approved.

In order to obtain the optimum performance from your selected Teamac Antifouling it is vital that the surface is correctly prepared. 

The following information is designed to advise how this may be achieved.

There are five sections:-

1.    Special notes to consider before applying antifouling.
2.    Selection criteria and compatibility to previous coatings.
3.    The types of Antifouling and associated products.
4.    The application of Teamac Antifouling.
5.    Health and Safety during preparation and application.

We strongly recommend reading all the relevant sections, as well as details and instructions provided on the tin and the Technical Health and Safety data sheets, before applying the selected product.  Should you have any doubt about the product, how to use it, compatibility etc, please contact us on 01234 273388

• SPECIAL NOTES TO CONSIDER APPLYING ANTIFOULING

We have tried to list as many as possible of the specific problems which have often to be overcome on boat hulls and structures exposed to the marine environment, either before or when applying antifouling.

a) Menaces to Wooden Hulls

There are two principal menaces to the structure of wooden boats operated in British
Waters – Teredo and Gribble.

Teredo Shipworm is a borer which may attack your boat’s hull.  There are at least three species to be found in British waters.  The free swimming larvae of this worm attach themselves to unprotected areas of wooden hulls and then turn into bivalve molluscs, in this form they bore into the wood through holes often no bigger than a pin’s head and then they start to become worm-shaped.

In the form of  worms with cutting teeth in their shell-like heads, they continue to bore straight in and then, they begin to grow, they feed on the cellulose in the wood.  Worms of up to nine inches long in British waters and up to six feet in tropical waters have been found inside planks with nothing larger than pinholes on the surface to show where they had entered.

Another type of borer which may attack your boat is the Gribble – a worm which resembles a woodlouse but is only one sixth to one third of an inch in length.  The behaviour of the Gribble is quite different from that of the Teredo.  It bores into unprotected timber to a depth of about two inches and then returns to the surface to select another point of entry.  It quickly reduces an area of planking to a pulpy mess which is washed away: then it repeats the process further in.

It is possible that your boat might be attacked by molluscs called Martesia which are often found in localities where Teredo worms are prevalent.  Martesia resembles elongated cockles, rather than worms, and do not bore into planking like Teredo but excavate burrows on the surface.  They are not therefore such a hidden menace but since they can grow to a length of two inches and breadth of over half and inch while excavating burrows longer than themselves, they are still a very definite one; the more so as they attack in large numbers.

b) Fouling to All Types of Hulls

Sea water, in harbours and estuaries, contains immense numbers of microscopic organisms and plants collectively known as plankton.  If given a chance, many of these will settle on the hull of a boat and grow.  They constitute a menace because, as they grow, they increasingly reduce the boat’s speed through the water and its manoeuvrability, and are a direct cause if increased fuel consumption.

Greatest menace among fouling organisms is the barnacle which can grow until it measures 3 inches across the base.  Other animal shell growths include mussels and serpulidae.  The latter form masses of coiled and tangled white shell like tubes, often described as “coral”.

Other growths are formed by ascidians or tunicates which, at the larvae stage, resemble minute tadpoles.  They are usually called jelly-bags or sea squirts.  Others are formed by polyzoa, sometimes in the form of mats which other organisms may attach themselves; and by hydroids.  Those formed by the latter are scientifically known as tubulana, colloquially as roses.

Weed growths include a green ribbon grass known as entermorpha; a brown weed called ectocarpus; and a red one called polysiphonia.  They are distantly related to a slimy, moss like growth likely to be composed of vegetable growths and seaweed related organisms called diatoms.  The slime does not adversely affect a boat’s speed much but weeds certainly do.

c) Antifoulings and Aluminium Hulls

Aluminium has been used in boat building because it is strong for its weight and is relatively easy to work.  However it has proved prone to oxidisation and then structural breakdown.  In addition it is important to prevent contact between copper (present in many antifoulings) and the aluminium.  There can be a reaction between the “salts” of copper and the aluminium metal resulting in further breakdown of the aluminium surface.  These points should be considered when using any antifouling compound containing copper.  An “insulating” coating such as Teamac Metaclor should be used to prevent contact between the antifouling and the aluminium.  If the Barrier is broken it should be repaired quickly to prevent hull damage.

d) Osmosis in GRP Hulls

Osmosis is caused by the absorption of water into “impurity salts” persistent in the materials which make up the glass fibre hulls.  This causes “Blisters” to appear in the hull as water pressure pushes on the Gel coat from underneath.

Although small areas can be treated, once blisters are present throughout the hull, complete replacement of the gel coat is recommended.  A specialist should be consulted.  (Teamac Antifouling paints can help act as a barrier to protect your hull).

e) Rust in Steel Hulls

Rust must be fully removed from steel hulled boats before priming.  Once present, iron oxide will continue to break the structure of the hull until removed.

f) Efflorescence in Ferro Concrete Hulls

This is the formation of salts resulting in the breakdown of the structure of the Ferro Concrete hull.  The best way to treat this is to clean away the source and provide a barrier to protect the hull inside and out.

g) Special Notes:

Amateur Use:- Apply by brush or roller only (not by spray).  Wear suitable protective gloves.
Professional Use:- Apply by brush, roller or spray.  Do not breathe spray mist.  Wear suitable protective clothing (coveralls: of a contrasting colour to the product being applied, underneath a disposable coverall with hood), suitable gloved and impervious footwear that protects the lower leg.  Wear suitable respiratory equipment (such as air fed respiratory equipment with combined helmet and visor) when spraying.  Dispose of protective gloves after use.  Unprotected persons should be kept away from treated areas.
In case of fire use sand, earth, foam or water fog.
This material and/or its container must be disposed of as hazardous waste.

• SELECTION CRITERIA AND COMPATIBILITY

There are two grades of Teamac Antifoulings which are listed below in order of their performance (strongest shown last):

Tropical Killa
Antifouling D

Teamac “Metaclor” Underwater Primer is a metallised chlorinated rubber water and chemical resistant primer which provides an ideal primer/undercoat for further application of the selected antifouling coating (1 litre, 2.5 litre, 5 litre tin sizes).  It is suitable for use on wood, metal and Ferro concrete and aluminium surfaces.

Teamac Tropical Killa Antifouling offers good Antifouling performance and a good level of protection at an economical price.  It is designed for 12-18 months.  This product is suitable for domestic and commercial craft (1 litre, 2.5 litres, 5 litres, 20 litres Red).  Maximum boat speed 30 knots.  Slipping/immersion time min 12 hours max 3-5 days.

Teamac “D” Antifouling is a physically ablative product and offers excellent antifouling performance whilst maintaining a good level of protection.  It is a mixture of soluble medium with insoluble polymers to form a matrix which wears away physically at a controlled rate.  It is new to the market in a range of colours.  Developed over many years involving static and field trials this product is suited to most vessels in a wide range of waters.  It has a softer film than Tropical Killa but has a superior antifouling performance.  It is available in Red, Blue, Green, Grey, Black colours and litre, 2.5 litre, 5 litre tin sizes, 2-3 coats should be used. Maximum boat speed 20-25 knots.  Slipping/immersion time min 12 hours, max 2 weeks.

In all cases full technical, health and safety information is available.  A compatibility chart is shown to help when changing systems but if in any doubt or if seeking advice on any product please contact us on 01234 273388

All Teamac antifoulings are tin free and have full H.S.E. Licenses and are suitable for use on wood, iron, steel, Ferro concrete and GRP hulls ( unsuitable for use on aluminium hulls unless protected by a suitable barrier coat).

In order to obtain the best performance from the selected Teamac Antifouling it is important to ensure the preparation and application are correct.  This includes ensuring that the product you have selected does not react with the previous coating.  In an ideal world all old antifouling should be removed back to a firm substrate.  This is not always practical and more often than not the selected Teamac Antifouling will be applied directly over many types of products and no problems experienced.

The general preparation shown below can be used.  (See application of Teamac Antifoulings for more details).  It should be noted that, due to the variety of products now on the market, an application of the new antifouling to a small area first is the only way to test to ensure compatibility.  Leave the “Test Area” overnight and examine it carefully the next day.  Any sign of reaction (i.e. blistering, splintering or flaking, colour inconsistency etc) and either the barrier coat must be applied or all the old antifouling removed.

“Hard” Antifoulings:

Clean down and remove all traces of fouling, loose material, dirt, etc.  Sand down the cleaned surface with a medium grade wet paper (e.g. 120-180 grade).  This will provide a “key” for the new Teamac Antifouling.

Copolymer/Ablative Antifoulings:

Remove as much of the residue of the old antifouling as possible.  Remove all unstable paint, traces of fouling etc.  Once you are back to a firm surface apply new Teamac Antifouling.

Scrub able / Leaching Type Antifouling:

Thoroughly clean the surface to remove all traces of dirt, fouling etc.  Apply the new Teamac Antifouling.

If in any doubt about antifouling please contact us on 01234 273388

• APPLICATION OF TEAMAC ANTIFOULINGS

Always thoroughly stir all products until there is an even consistency throughout the container.

Wood: New Unpainted Surfaces.

Ensure the surface is clean and dry.  Sand down and fill as necessary.  Apply three coats of Teamac Metaclor Underwater Primer followed by two coats of Teamac Antifouling of your choice.

Wood: Old Previously Painted Surfaces.

Thoroughly clean down the surface and remove all loose and flaking material.   Remove all old antifouling until a firm substrate remains.  Spot prime with at least two coats of Metaclor Underwater Primer.  Now apply two full coats of the Teamac Antifouling of your choice.  If the hull has a combination of old paints and primers which you do not want to remove Teamac Metaclor Primer can be applied to help avoid compatibility problems.

Metal: New Unpainted Surfaces.

Ensure the surface is clean, dry, free of rust and thoroughly degreased.  If shot blasted the Metaclor must be applied immediately after shot blasting has finished.  Apply at least two coats of Teamac Metaclor Underwater Primer followed by two coats of the chosen Teamac Antifouling.

Metal: Old Previously Painted Surfaces.

Thoroughly clean down the surface and remove any old flaking paint.  Remove all old antifouling until a firm substrate is obtained.  Remove all rust, then spot prime any exposed metal areas with at least two coats of Metaclor Underwater Primer and then apply the chosen Teamac Antifouling.
If the hull has a combination of old paints of unknown origin which cannot be removed for whatever reason, Teamac Metaclor Primer can be applied once the surface has been cleaned down.  Then apply two coats of the chosen Teamac Antifouling.

GRP: New Unpainted Surfaces.

Ensure the surface is degreased, clean and dry.  Sand down lightly (but thoroughly) to provide a good “key” for the antifouling.  Apply two or three coats of the chosen Teamac Antifouling to the prepared surface.

GRP: Previously Painted Surfaces.

Remove any loose or flaking material.  Ensure a firm and dry substrate.  Sand down lightly (but thoroughly) any exposed GRP and spot prime with the chosen antifouling.  Then apply two complete coats of the chosen antifouling.

Ferro Concrete: New Unpainted Surfaces.

Ensure the surface is clean, dry and free of any oil or grease.  Seal the surface with a coat of Teamac Chlorvar White thinned 10% withV/607/15 Thinners then apply two coats of Metaclor Underwater Primer followed by two coats of the selected Teamac Antifouling.

Ferro Concrete: Previously Painted Surfaces.

Remove any loose and flaking material.  Spot prime any exposed areas with a coat of Metaclor Underwater primer thinned 10% with V/607/15 Thinners.  If there is an uneven film of unknown previous paints Teamac Metaclor Primer may be used prior to the application of the selected antifouling to help with adhesion and compatibility.

• ANTIFOULING COMPOSITION HEALTH & SAFETY

Flammable

Store and use away from sources of flame and heat

During Use

All Antifoulings contain constituents which may be harmful to skin and eyes and by ingestion and inhalation.  Avoid contact with skin and eyes.  The wearing of impervious gloves, goggles and protective clothing is recommended.
Ensure good ventilation and good inhaling vapour.  Any splashes on skin should be removed immediately with absorbent cloth, the affected area cleaned with proprietary hand cleaner and washed with soap and warm water.  Good standards of personal hygiene are essential.
Keep tin closed when not in use and store away from children and animals.  Do not use on surfaces which might be chewed by children or animals.  Do not burn off or rub down antifouling dry, as fumes and dust can be harmful to health.
All waste should be disposed of in the correct manner, i.e. in accordance with the Environmental Protection Act (Special Waste Terms).

If in any doubt about health and safety please contact us on 01234 273388