Duralac Anti-Corrosive Joint Compound, 115ml

Essential Protection Against Galvanic Corrosion

When two different metals come into contact in the presence of saltwater or moisture, an electrochemical reaction can occur, leading to galvanic corrosion.

This is a particularly important issue onboard yachts and boats, where combinations such as aluminium, stainless steel and other metals are regularly exposed to salt-laden air and seawater.

Duralac Anti-Corrosive Joint Compound is designed to form a protective barrier between contacting materials, helping inhibit the electrolytic reaction responsible for corrosion.

It is an essential product for marine installations, assembly work, refits and maintenance where different metals must be joined together.

Designed for Marine Environments

The marine environment is particularly demanding because seawater acts as an electrolyte and can dramatically accelerate corrosion between dissimilar metals.

Duralac is therefore extremely useful for yacht and boat applications including:

• Aluminium masts
• Stainless steel fittings on aluminium
• Bolts and screws
• Rivets
• Winches
• Aerials and antenna installations
• Deck hardware
• Aluminium plates and extrusions
• Battery-related fittings
• Marine equipment installations
• Metal-to-metal joints
• General yacht refit and maintenance work

Applying Duralac during installation can significantly improve protection at the contact point, where corrosion is often difficult to detect until damage has already occurred.

Helps Prevent Galvanic & Electrolytic Corrosion

Galvanic corrosion can occur when:

two dissimilar metals + an electrolyte such as seawater = an electrochemical cell.

One of the metals can then corrode much faster than it normally would.

Duralac works by creating a protective barrier at the joint, reducing direct exposure to the electrolyte and helping inhibit the corrosion process.

This makes it particularly valuable when installing stainless steel fasteners into aluminium structures, one of the most common mixed-metal combinations found onboard.

Ideal for Aluminium & Stainless Steel Connections

A typical yacht application is the installation of stainless steel screws, bolts, rivets or fittings onto aluminium.

Without suitable isolation, the combination of stainless steel, aluminium and saltwater can lead to accelerated corrosion around the aluminium component.

Applying Duralac to the contact surfaces before assembly helps isolate these materials and offers long-term protection.

Typical applications include:

• Stainless steel bolts in aluminium
• Stainless steel screws on aluminium structures
• Rivets in aluminium plates
• Mast hardware
• Aluminium deck fittings
• Antenna brackets
• Marine hardware installations

More Than Just Metal-to-Metal Protection

Duralac can also provide protection where metals come into contact with other materials.

Suitable applications can include metal interfaces with:

• Wood
• Synthetic resin materials
• Composite materials
• Rubber
• Leather
• Fabrics

This versatility makes Duralac useful across a wide range of yacht-building, refit and general engineering applications.

Excellent Resistance to Water

One of the reasons Duralac is particularly suitable for marine use is its strong resistance to water.

The compound offers:

• Low solubility in water
• Very low water absorption
• Excellent adhesion to many substrates
• A tough and flexible protective barrier

These characteristics help it remain effective in locations exposed to moisture, seawater and salt-laden marine environments.

Excellent Adhesion

Duralac offers strong adhesion to a wide variety of surfaces.

Once applied, the compound forms a protective layer between components, helping isolate the surfaces while remaining suitable for tightly assembled joints.

Its combination of adhesion, flexibility and low water absorption makes it particularly useful in areas where corrosion protection needs to remain effective over time.

Ready to Use

Duralac is supplied ready for application.

It should not be thinned before use.

The compound can be applied to the required contact surfaces before components are assembled.

For larger accessible surfaces, application with a small brush can help achieve an even coating.

Important: Assemble While Duralac Is Still Tacky

Correct assembly is important for optimum protection.

After Duralac is applied, the solvent begins to evaporate and the surface becomes touch-dry while remaining tacky for a period.

The components should be assembled while the compound is still tacky.

This allows Duralac to flow under pressure and fill small gaps between the mating surfaces, helping create a more complete protective barrier.

Do not leave a thin exposed coating for an unnecessarily long period before assembling the joint, as it can begin to harden and prevent the joint from closing correctly.

How to Use Duralac

1. Make sure both mating surfaces are clean and free from grease, dirt, oxidation and loose contamination.
2. Apply Duralac to the contact surfaces.
3. Ensure areas particularly vulnerable to galvanic corrosion are adequately covered.
4. Apply the compound to bolts, screws or rivet contact areas where appropriate.
5. Assemble the components while Duralac remains tacky.
6. Tighten the fasteners according to the equipment manufacturer’s specifications.
7. Remove unnecessary excess material where required.
8. Close the tube securely after use.

For professional installations, always follow the current Technical Data Sheet and Safety Data Sheet.

Why Use Duralac on a Yacht?

A small amount of galvanic corrosion around a fitting can eventually become an expensive structural or cosmetic repair.

This is especially true for aluminium components, masts and deck hardware where stainless steel fasteners are commonly installed.

Using Duralac during assembly is a simple preventive step that can help protect expensive yacht hardware and reduce corrosion-related maintenance.

For captains, engineers, riggers and professional yacht maintenance teams, it is therefore an extremely useful product to keep available onboard or in the workshop.

Key Benefits

• Helps prevent galvanic corrosion
• Helps inhibit electrolytic corrosion
• Designed for joints between dissimilar metals
• Particularly useful between aluminium and stainless steel
• Excellent for marine and saltwater environments
• Ideal for bolts, screws and rivets
• Suitable for aluminium plates and extrusions
• Excellent for mast and rigging hardware installations
• Useful on winches, aerials and marine fittings
• Excellent adhesion to many substrates
• Low solubility in water
• Very low water absorption
• Tough and flexible protective barrier
• Supplied ready for use
• Ideal for yacht building, refit and maintenance
• Convenient 115ml tube

Recommended Yacht Applications

Ideal for:

• Aluminium masts
• Mast fittings
• Rigging hardware
• Stainless steel fasteners in aluminium
• Deck hardware
• Winches
• Antenna and aerial installations
• Bolts
• Screws
• Rivets
• Aluminium plates
• Aluminium extrusions
• Battery installations
• Marine hardware
• Yacht refits
• Boat construction
• General marine engineering

Technical Specifications

Brand: Duralac
Manufacturer: Llewellyn Ryland Ltd.
Product Type: Anti-Corrosive Jointing Compound
Primary Function: Prevention of galvanic / electrolytic corrosion
Application: Joints between dissimilar metals and compatible materials
Form: Paste / Jointing Compound
Marine Use: Yes
Water Resistance: Low water solubility and very low water absorption
Application Condition: Supplied ready for use – do not thin
Recommended Assembly: Join components while compound remains tacky
Packaging: Tube
Capacity: 115ml
Cavo Yachting Product Code: XYCE000011182

Storage & Safety

Duralac is a professional chemical product and should be handled according to the information provided on its packaging and current Safety Data Sheet.

For safe use:

• Wear suitable protective gloves.
• Avoid unnecessary skin and eye contact.
• Work in a suitably ventilated area.
• Avoid breathing vapors.
• Prevent release of the product into the marine environment.
• Keep the container securely closed when not in use.
• Store in accordance with the manufacturer’s instructions.
• Keep away from children.
• Dispose of unused material and packaging according to applicable local regulations.