How To: Applying Spreader & Chafe Patches

Protecting Your Sails the Right Way

Modern sails work hard. Each tack, gybe and manoeuvre places load and movement into the sailcloth and where sails encounter rigging, chafe is inevitable. Spreader and chafe patches are a simple but critical detail that protects your sails from unnecessary wear and significantly extends their working life. When applied correctly, these patches act as sacrificial protection, taking the abrasion so the sail itself doesn’t have to.

What Are Spreader & Chafe Patches?

Spreader patches are typically made from sticky-back insignia or Dacron cloth and are bonded directly onto the sail. Their purpose is to protect high-wear areas where the sail regularly presses against spreader tips, shrouds, stanchions, or deck hardware. Rather than allowing repeated abrasion to damage the sailcloth itself, the patch absorbs the wear and can be replaced when required – preserving the sail underneath. On performance laminates and membranes, this protection is especially important, as even small areas of repeated chafe can quickly lead to structural damage.

When Should Spreader Patches Be Applied?

If we have identified spreader contact as a concern, patches will either be supplied already fitted or included loose with the sail.

Spreader patches are strongly recommended if:

• You race regularly
• Your genoa overlaps the spreaders when sheeted
• You sail in stronger breeze where loads are higher
• Your rig geometry brings sails into frequent contact with hardware

Never race or sail hard with an unprotected sail if spreader contact is expected.

Finding the Correct Patch Position

Accurate placement is key:

1. Hoist the sail in light conditions and sheet it in firmly.
2. From a bosun’s chair, mark where the spreader contacts the sail when fully trimmed.
3. The patch should extend forward of this point and all the way to the leech.
4. Because the leech rises as the sheet is eased, position the patch so approximately three-quarters of it sits below the contact mark when the sail is sheeted hard.
5. Mark both sides of the sail as patches must always be applied port and starboard.

Before lowering the sail, also mark:

• Where the sail touches stanchions
• Where the foot brushes shroud bases

These areas often benefit from additional chafe protection.

Preparing the Sail

Before applying any patches:

• Ensure the sail is completely dry
• Remove salt and dirt
• Lay the sail out on a large, flat surface
• Keep the sail under light tension so the surface remains smooth

Trapped air bubbles weaken adhesion and reduce patch lifespan.

Applying the Patch

1. Position and mark
   Place the patch in its intended position and lightly mark the outline using pencil, chalk, or tape. Allow the patch to overlap the leech by 25–50 mm so it can be wrapped around.
2. Start from the leech
   Fold back the first few cm’s of backing paper and tack the patch in place at the leech. Ensure it runs parallel to the waterline.
3. Apply gradually
   Working forward, peel away the backing a little at a time while smoothing the patch down firmly. Use your hand or a soft, flat tool to push air out as you go.
4. Maintain tension
   Keeping the sail under gentle tension (often using knees or hands) helps prevent wrinkles and ensures a clean bond.
5. Wrap the leech
   Once the patch is fully applied, fold the overhanging section around the leech and press it firmly onto the opposite side. Trim excess if required.
6. Final pressure
   Use a plastic applicator or wallpaper roller to firmly bed the patch into the sailcloth.
7. Repeat on the opposite side

After Installation

Inspect patches regularly. They are designed to wear; that’s their job. Once a patch becomes thin or damaged, replace it before the underlying sailcloth is exposed. If a spreader ever punctures the sail, stop sailing and have the area professionally repaired. A proper repair will reinforce the area beneath the patch to restore strength and prevent further damage.

The Sanders Approach

Attention to detail like this is what separates sails that merely survive from sails that perform and last. Correctly applied spreader and chafe patches:

• Extend sail life
• Protect performance materials
• Reduce repair costs
• Improve reliability when sailing hard

If you’re unsure about placement, materials, or whether your sails would benefit from additional protection, your local Sanders loft is always happy to advise — or apply patches professionally.