What are the methods for stripping wax from optical cable splices

Wax or protective coatings on optical fibers can be removed using mechanical, chemical, or thermal methods, with careful cleaning to preserve fiber integrity.

Mechanical Stripping

Mechanical stripping uses precision tools designed to remove the fiber coating or wax without damaging the glass core. Common tools include handheld fiber strippers, adjustable strippers for non-standard diameters, and automated stripping machines. The process involves: Using a fiber stripper to remove the buffer coating or wax over a defined length (typically 30–40 mm) without nicking the fiber.

Minimizing the number of passes to reduce surface flaws on the glass, which can weaken the fiber. For multi-layer cables, stripping is done progressively: first the jacket, then aramid yarn, and finally the buffer coating. Mechanical stripping is generally preferred because it produces a clean, well-defined coating termination and avoids chemical residue.

Chemical Stripping

Chemical methods dissolve the wax or coating using solvents or acids. Common approaches include: Applying high-purity alcohol (e.g., 99% isopropyl alcohol) with a lint-free pad to remove residual wax or gel. Using specialized solvents or degreasers compatible with optical fibers, such as Fiber-Clean™, d'Gel, or HydraSol, to wipe off petroleum-based gels.

For more stubborn coatings, chemical strippers like paint stripper gels or controlled exposure to sulfuric acid (H₂SO₄) at elevated temperatures can soften the coating for removal with lens tissue. Care must be taken to remove all chemical residues, as leftover solvents can continue to soften the coating and compromise splice reliability. Chemical stripping is recommended when very high reliability is required, but it requires careful handling and adherence to safety regulations due to potential hazards from solvents or acids.

Thermal Stripping

Thermal methods soften the coating or wax using heat, making it easier to remove mechanically: Heated hand tools or thermal strippers (e.g., Vytran FFS-2000, FiberStrip 7030) can safely strip coatings on standard and specialty fibers. Some tools combine heat with mechanical stripping to reduce the risk of fiber damage and improve consistency.

Best Practices

Always use lint-free materials to avoid contamination. Wear safety glasses and work in a clean area to prevent injury from fiber shards or chemical exposure. For multi-layer cables, strip each layer individually to avoid damaging underlying fibers.

Inspect the stripped fiber to ensure a clean, straight edge without jagged or torn coating. By combining these methods appropriately, technicians can safely and effectively remove wax or protective coatings from optical cable splices while maintaining fiber strength and splice reliability.