F2 EcoHull is a special fouling-release system – not a classic antifouling paint. When applied correctly, you get a very smooth, robust surface that is easy to clean and offers good performance over several seasons.

Application is also achievable for DIY users, provided you follow the instructions precisely. Deviations can lead to poor adhesion or detachment of the coating.

IMPORTANT SAFETY INSTRUCTIONS

• Risk of slipping: The F2 surface is extremely smooth. Secure the vessel appropriately during lifting and blocking.
• Personal protective equipment: Always use gloves, safety glasses, and protective clothing. A mask is recommended but not mandatory.
• Fire hazard: Larger quantities of F2 EcoPrimer residues generate strong heat during curing. Never leave residues unattended.

Understanding the F2 EcoHull System

Each component has its own technical function:

• F2 Degreasing Solution: Environmentally friendly, solvent-free cleaner. Dilute 1:10 with water.
• F2 EcoPrimer: Water-based 2K epoxy primer. Acts as a bonding bridge, but not as osmotic protection.
• F2 EcoHull Adhesive Coat: 1K polymer bonding layer and color base. Mix thoroughly.
• F2 EcoHull Top Coat: Final transparent protective layer, with or without Sparkle effect.

Tip: Top Coat with Sparkle effect helps to visualize uniform coating thickness.

Brief Overview

The substrate must be dry, clean, and load-bearing.

Do not use solvents – only Degreasing Solution.

Consumption: approximately 10 m²/L. Do not apply too thinly.

Mixing is important – use a mixing attachment.

1. Preparation and Environmental Conditions

1.1 Checklist – What you need to have ready

• F2 EcoPrimer, Adhesive Coat, and Top Coat
• F2 Degreasing Solution and personal protective equipment
• High-quality masking tape and eccentric sander
• Mixing attachment for cordless drill
• Epoxy mixing containers and paint trays
• Hard foam rollers or lint-free felt rollers (no long fibers!)
• Fine brushes and large paper roll for cleaning

2. Substrate Preparation

2.1 Scenario A: Hull is coated with antifouling

• Inspection: Thoroughly check the existing coating – are there blisters, cracks, flaking, or soft spots?
• Removal: Consistently remove anything that is damp, poorly adhered, soft, or brittle until a clean and load-bearing substrate is reached.
• Silicone: Silicone coatings must be completely removed without residue.
• Coppercoat: Coppercoat coating usually does not need to be completely removed; sanding until the green oxidation layer is completely gone is sufficient. Then clean very thoroughly.

Tip: If in doubt, we recommend removing old antifouling down to the basic barrier coat. This way, you start with a clean substrate to which F2 EcoHull adheres optimally.

2.2 Scenario B: Hull is “bare” (new or sanded)

If the hull is “bare,” we recommend applying a barrier coat for osmosis or corrosion protection before applying F2 EcoHull.

Tip: Although F2 EcoHull creates a water-repellent surface, it is generally not sufficient as a barrier coat against osmosis and corrosion.

Which primer to use?

• 2K epoxy primer with low solvent content (e.g., Hempel Light or Hempel High Protect II) can be easily overcoated with F2 EcoHull Adhesive Coat within 24 hours. If work continues beyond 24 hours, the surface must be thoroughly sanded with P180 and cleaned.
• Solvent-based 2K epoxy primers: Can be used, but must dry for at least 7 days at 20 °C after application for solvents to evaporate. Then the surface must be sanded with P180 and cleaned.

Tip: If you apply a fresh 2K epoxy primer, you can often proceed directly with the Adhesive Coat (step 3.2) and skip the EcoPrimer.

2.3 Sanding and Cleaning

• Sanding: Sand with an eccentric sander (grit P80–180) until you achieve a uniformly matte and smooth surface. Treat edges and hard-to-reach areas manually.
• Cleaning: Dilute F2 Degreasing Solution 1:10 with fresh water.
• Wiping technique: Wipe with a clean sponge or cloth in one direction only. Do not rub back and forth, as this will only spread grease and dirt. Repeat if necessary until the surface is completely clean.
• Rinsing: After degreasing, thoroughly rinse the surface with clean water.
• Drying: The substrate must be completely dry before the first application. Moisture under the coating will inevitably lead to detachment.

Tip: Never use acetone, nitro thinner, or other solvents. They can damage the surface or leave invisible residues that interfere with the chemical bonding of F2 EcoHull.
Tip: If in doubt, check dryness with a moisture meter.

3. Application Process

For all layers: the goal is a uniform, closed wet film with a slight sheen. If the layer is uneven or dry, apply a little more material.

• Consumption: approximately 10 m²/L (per component) ≈ thickness ~100 microns per layer.
• Technique: apply in a cross-hatch pattern (horizontally, then vertically).
• Support system (overlapping):
  When painting, leave a 5 cm edge for the primer (for Adhesive Coat) and a 5 cm edge for the Adhesive Coat (for Top Coat). This allows for correct application later when moving the supports.

3.1 F2 EcoPrimer (2K system)

A. Mixing

• Observe pot life: Since the material reacts quickly after mixing, only mix as much as you can safely use within the working time. The pot life is approximately 30 minutes at 20 °C.

Tip: Higher temperatures mean shorter working time. If necessary, place the cans in a cold water bath.

• Pre-mixing: Before taking out the contents of the BASE, thoroughly mix it in the can to homogenize settled components.
• Mixing: Mix BASE and ACTIVATOR in the exact ratio of 60:40 in a clean mixing container.
• No additives: Do not thin the primer. Adding water or solvents destroys the chemical formula.

Safety (fire hazard): Mixed 2K systems generate heat during curing. Large amounts of residue in containers can cause intense heating. Never leave containers with residue unattended on flammable surfaces.

B. Application

• Layer thickness: Target coverage is approximately 10 m²/l. Apply the material neither too thin nor too thick to achieve a closed film.
• Cross application: Apply the primer in a cross pattern – first horizontally, then immediately vertically. This ensures the hull structure is completely wetted.

C. Time and intervals

• Recoat window: The primer is touch-dry after approximately 4 hours at 20°C and ready for the next coat.
• 24-hour window: The best chemical bond with the next layer (Adhesive Coat) is achieved if applied within 24 hours.
• If interval is exceeded: If more than 24 hours pass, the surface is too hardened. The surface must be re-sanded with P180 and cleaned to establish mechanical adhesion.

3.2 F2 EcoHull Adhesive Coat (1K)

Adhesive Coat is a one-component polymer that acts as both a bonding and color layer.

A. Preparation

• Mix thoroughly: Open the can and mix the contents very well (preferably with a machine mixer). Pigments tend to settle at the bottom.
• Do not thin: The material is ready to use and must not be thinned.

B. Application

• Full coat: Ensure good coverage (~10 m²/l). Do not apply too thin.
• Cross application: First horizontally, then vertically. The goal is a completely even and smooth film without defects.
• Supports: Leave approximately 5 cm border around supports to the edge of the primer.

C. Time and intervals

• Drying: The layer is touch-dry after approximately 4 hours at 20°C.
• Recoat window: A major advantage of Adhesive Coat is that there is no maximum interval for the next layer. Top Coat can be applied even after several days if the surface is clean, dry, and dust-free.

3.3 F2 EcoHull Top Coat (1K)

Top Coat is the functional layer that provides the fouling-release effect and speed.

• Application: Same as Adhesive Coat – mix well and apply in cross pattern (~10 m²/l). Do not thin.
• Immediate corrections: Immediately level any drips or runs.
• Overlap: Again leave a 5 cm border to the edge of Adhesive Coat to allow for later overlap application after moving supports.
• Drying time: Top Coat is touch-dry after approximately 4 hours.

4. Lifting, curing and maintenance

This final step is crucial. Although the coating is already applied, it only now achieves its final mechanical properties. Since F2 EcoHull is extremely smooth, special care is required when handling the vessel.

4.1 Preparation for lifting

Before the lift operator installs the straps, consider the following to prevent damage to the vessel or coating:

• Waiting time: After applying Top Coat, wait at least 36 hours before suspending the vessel in straps. The coating must be sufficiently pressure-resistant to bear the weight of the vessel.

Tip: Curing can be accelerated if necessary by lightly moistening the surface.

Anti-slip protection (IMPORTANT): Ask the lift operator to tie the straps under the hull together so they cannot spread apart.

Safety (slip hazard): Due to the extremely smooth surface, there is a risk that straps may slip or spread apart.

• Clean straps: Ensure the straps are clean, without sand or sharp edges. If possible, use soft padding or felt between the strap and hull to protect the fresh coating.
• Tackiness: Do not be surprised if Top Coat is initially slightly tacky. This is normal and disappears when the vessel is in water.

4.2 Treatment of areas under supports

When the vessel is suspended in the lift (or moved), the areas where it previously stood on supports become accessible. These areas must be re-treated.

• Preparation: Sand these areas with P180 and thoroughly clean with Degreasing Solution (1:10). Allow to dry.
• Layer application: Then quickly apply the missing layers (as needed: Primer – Adhesive Coat – Top Coat).
• Overlap: New layers should overlap the edges of the already painted surface. Due to the previously left borders (5 cm), you will achieve a smooth, invisible transition.
• Launch: For these small areas, you do not need to wait an additional 36 hours. The vessel can be launched when the Top Coat in these areas is touch-dry (approximately 4–6 hours).

4.3 Curing and first weeks in water

F2 EcoHull is a modern system that requires water to achieve final hardness.

• Curing process: Complete chemical curing is finished after approximately 8–12 weeks in water.
• Extended time on land: There is no limit to how long the vessel can remain on land before launching. If it remains dry for an extended period, curing can be supported by lightly spraying the hull with water (when the coating is touch-dry).
• First cleaning (“Early Clean”): After the first 8–12 weeks in water, we recommend gentle cleaning with a soft sponge or cloth. This removes the initial biofilm and allows the fouling-release system to achieve full effectiveness.

Tip: Never use hard brushes, coarse sponges, or aggressive chemicals. The surface is designed for self-cleaning – gentle wiping with a soft brush or cloth is sufficient.

Tip: After complete curing, the F2 EcoHull surface can also be cleaned with a pressure washer. Maintain sufficient distance and use only as much pressure as necessary.

Clean and professional hull preparation is the most important step for a long-lasting F2 coating. Only if the substrate is dry, clean, and in good condition can F2 EcoHull adhere optimally and provide its full effectiveness.

In this article, you will learn step by step how to prepare the hull so you can begin applying F2 coating without “old” layers trapped underneath.

Quick overview: key steps

1. Check hull condition (moisture, old coatings, damage).
2. Sand old antifouling layers evenly down to the base primer (our clear recommendation).
3. Apply barrier coat/primer as needed (especially on new or bare hulls).
4. Sand the hull evenly (P80–180), finish edges and details.
5. Thoroughly clean and degrease with F2 Degreasing Solution – without using solvents.
6. Ensure everything is dry, dust-free, and ready for F2 coating.

1. Planning and conditions

Depending on the boat size, condition of old coatings, and your work speed, plan approximately 2–3 working days for hull preparation (excluding actual F2 coating application). Thorough preparation saves you many problems later – poorly prepared substrate under F2 is very difficult to repair later.

1.1 Checklist – what you need to have ready

• Orbital sander with sanding discs P80–180
• Sanding block / hand sandpaper for edges and hard-to-reach areas
• F2 Degreasing Solution
• Clean buckets and soft sponges/cloths
• Protective materials (film, tape) for waterline, hardware, etc.
• Protective equipment: dust mask, safety glasses, gloves, hearing protection
• Optional: hull moisture meter

1.2 Environmental conditions

Pay attention to proper conditions even during preparation – temperature and humidity become especially important when you begin applying the coating.

2. Hull condition assessment

Before taking the sander in hand, the hull must be thoroughly inspected. This initial assessment determines how aggressively old coats need to be removed.

2.1 Visual inspection

• Are there blisters, peeling or cracks on the old antifouling?
• Soft, greasy or heavily chalky areas?
• Areas with previous repairs or osmotic blister treatment?
• Surfaces covered with silicone, sealant or special systems?

2.2 Moisture testing

F2 coatings must not be applied to a wet hull. If you are unsure, a moisture meter (especially for GRP) can help identify critical areas. Elevated moisture levels or suspected osmotic blisters must be addressed first – F2 must not be used as a “sealing layer” over existing problems.

3. Old antifouling coats: our clear recommendation

Important: For F2, we generally recommend consistently sanding old antifouling coats back to the base primer. This prevents old coats from being trapped under the F2 system and reduces the risk of subsequent peeling.

Traditional, soft antifoulings are not designed as a permanent base for modern fouling-release systems. Under the F2 layer, they can still move, swell, chalk or detach – in the worst case, they can compromise the entire coating.

3.1 Why “down to primer”?

• Soft or poorly bonded old coats always present a risk.
• Trapped coats can later cause blisters, cracks or extensive peeling.
• On primer/gelcoat/metal surfaces, you can select a clearly defined, stable coating system.
• You start with a “clean system” without unknown foreign products under F2.

3.2 How to remove old coats

• Mechanical removal: Depending on coat thickness, start with coarse abrasive (e.g., P60–P80) and gradually progress to finer (P80–P120).
• Controlled work: The goal is to sand to healthy primer – not aggressively into the laminate/metal. Regularly check which layer you are sanding.
• Silicones and special systems: Silicone coatings must be completely removed. Even small residues can severely interfere with F2 adhesion.
• Leveling and smoothing: Remove unevenness, scratches and sanding marks with appropriate sandpaper (e.g., P120–P180).

Only in exceptional cases – e.g., after recent professional hull refurbishment with a clearly documented system – can you consider whether complete removal is really necessary. Our standard recommendation remains: thoroughly remove old antifouling coats.

4. Bare hull and protective coatings

On new hulls or where you have sanded to completely bare surface (GRP, metal, wood), the substrate must be covered with an appropriate protective/barrier system before applying F2.

• GRP/gelcoat: Solvent-free epoxy barrier coating (e.g., Hempel High Protect II) for protection against moisture and osmosis.
• Aluminum/steel: Suitable anti-corrosion primer according to shipyard or manufacturer recommendation.
• Wood: Depending on the system, epoxy sealing coating or suitable primer so that F2 coats lie on a uniform, stable substrate.

If using a solvent-based primer, it must first cure completely (often at least 7 days at ~20°C). Only then must it be sanded and degreased with F2 Degreasing Solution before applying the F2 system.

5. Sanding – foundation for adhesion and final appearance

After removing old antifouling coats (and after any protective barrier layer), the hull is sanded to create a uniform, slightly matte surface.

1. Grit range: Usually P80–P180 works well. Coarse grits (P80) for old, stubborn coatings, fine grits (P120–P180) for final sanding.
2. Work evenly: Use a random orbital sander with overlapping movements for an even sanding pattern.
3. Edges and details: Sand edges, curves and hard-to-reach areas by hand so that no sharp transitions or unsanded spots remain.
4. Remove dust: Regularly vacuum or sweep dust to clearly see remaining unevenness and old coats.

6. Cleaning and degreasing – final step before F2

After sanding, the hull must be completely free of dust, grease, oil and wax. Only then can the F2 coating reliably adhere.

6.1 Initial cleaning

• Thoroughly vacuum or sweep sanding dust.
• Rinse the hull with fresh water to remove salt and dirt.
• Allow everything to dry completely.

6.2 Degreasing with F2 Degreasing Solution

• Mixing: Dilute F2 Degreasing Solution in a 1:10 ratio with fresh water.
• Application: Apply the solution to the surface with a clean sponge or cloth.
• Wiping technique: Wipe only in one direction – do not rub back and forth to avoid redistributing dirt and grease.
• Repeat: Repeat the process as needed until the surface is clean and free of visible traces.
• Rinsing and drying: Rinse with clean water and allow the surface to dry completely.

Important: Do not use solvents (e.g., acetone, thinners) for final cleaning. They can leave residues that reduce F2 coating adhesion.

7. Final inspection: is the hull ready for F2?

Before starting application of the actual F2 coating, check the following list:

• All old antifouling coats are removed to healthy primer – no soft or unknown coatings remain under F2.
• The hull is dry; any osmotic problems have been properly addressed, not just “painted over.”
• All protective coatings/primers are completely cured and sanded.
• The surface is evenly matte and smoothly sanded.
• The hull is thoroughly cleaned and degreased with F2 Degreasing Solution.
• No visible dust, grease or silicone residues.

If you can check all these points, the hull is optimally prepared for F2 application – without old coats and with a clearly defined substrate. The next step is actual system application with F2 EcoPrimer (if needed), F2 EcoHull Adhesive Coat and F2 EcoHull Top Coat.

Whether you need primer depends on how your hull is currently configured. Most importantly: F2 must always be applied to a stable, clean and dry surface.

Short answer

• New or freshly sanded hull: Yes – first apply appropriate protective/barrier coating/primer, then F2 system.
• Intact barrier layer already present: No need for additional primer – sand, clean and then apply F2.
• Old antifouling: Antifouling is not primer. We recommend sanding the coats down to healthy, stable barrier layer/primer.
• Solvent-based primer: Allow to cure completely, sand, degrease – then continue directly with F2 EcoHull Adhesive Coat (without F2 EcoPrimer).

1. When you need additional primer

New or bare hull
For new hulls or hulls that have been completely sanded to bare surface, we recommend applying solvent-free barrier coating (e.g., Hempel High Protect II) under F2 to protect the hull from moisture. The F2 system is then built on top of this barrier layer – in this case F2 EcoPrimer is not needed.

Important: We recommend using solvent-free primer (e.g., Hempel High Protect II) so you can continue with F2 system application as specified in the instructions.

If using solvent-based primer, the surface must be allowed to outgas solvent for at least 7 days at 20°C before re-sanding (P180) and degreasing. Only then can you continue with F2 EcoHull Adhesive Coat application.

2. When additional primer is not required

Intact barrier layer already present

If a healthy barrier layer is already present (without blisters, cracks, or peeling), it is usually not necessary to apply a new primer.

• Remove old antifouling down to the healthy, load-bearing barrier layer (if present).
• Sand the barrier coating (e.g., P180) and clean thoroughly.
• Degrease with F2 Degreasing Solution (1:10 with water, wipe in one direction only, rinse, allow to dry).
• Then apply the F2 system according to instructions (F2 EcoPrimer if specified, F2 EcoHull Adhesive Coat, F2 EcoHull Top Coat).

3. Antifouling is not primer

Traditional antifoulings (especially soft systems) are not designed as a base layer for modern fouling-release systems like F2. If these layers remain under F2, they may later swell, chalk, or delaminate – which can compromise the entire F2 coating.

Our recommendation is clear: consistently sand old antifouling layers down to the healthy, load-bearing barrier layer/primer.

• Hard foam or felt rollers without fibers with a smooth surface.
• Rounded edges to prevent visible hard roller edges in the film.
• Short nap (not wool or long-nap rollers) to achieve a smooth surface.

For edges, through-hull fittings, and narrow surfaces, you can additionally use a fine brush.

Complete curing of the F2 coating takes 12 weeks.

The coating fully cures only in water. After 24–36 hours, the Top Coat is already hard enough for the vessel to be lifted with a crane and moved. For launching into water, the final layer (Top Coat) only needs to be surface dry.

Important notes regarding curing

• Initial feel: Immediately after application, F2 Top Coat is very tacky. This is normal and part of the curing process.
• Accelerating curing: Curing can be accelerated by lightly moistening the surface.
• “Early-Clean” (early cleaning): After 8–12 weeks, gentle cleaning with a cloth or sponge is beneficial if needed to remove initial biofilm and make subsequent colonization by larger organisms more difficult.

• Air temperature must be above 10°C.
• Surface temperature must be above 3°C.
• Air humidity should be at most 90%.
• The hull must be completely dry. Pay attention to condensation!

No, this is not necessary. F2 can remain on land indefinitely before the boat is launched into water.

What you need to watch for:

• Time before lifting with travel lift: Wait 24–36 hours before lifting the boat for the first time.
• Launching into water: The F2 coating can be launched into water as soon as the final layer (Top Coat) is touch dry.
• Complete curing: Although the boat can already be launched into water, complete curing only occurs in water and takes approximately 12 weeks. Curing also occurs on land, but is slower as it is only supported by air humidity.

After applying F2, there are several important points to watch for to avoid damaging the fresh coating and ensure safe lifting of the boat.

Waiting time and coating condition

• We recommend waiting 24–36 hours before lifting or moving stands. There is no maximum waiting time; the boat can remain on land indefinitely.
• Immediately after application, F2 Top Coat is very tacky. This is normal and part of the curing process.
• The curing process can be accelerated by lightly moistening the coating.

Important safety instructions

• Ensure that lifting straps are clean.
• Use protective padding if necessary to protect straps from the coating.
• Secure straps safely to prevent slipping.