Freund - Flux for oxidized zinc sheet

✔ Highly active special formula – Developed for heavily oxidized and weathered titanium zinc, old zinc, and galvanized steel sheet
✔ Dissolves thick oxide layers – Aggressive formulation of zinc chloride, ammonium chloride, and free hydrochloric acid easily breaks through passive layers
✔ Superior tin flow – Ensures ideal surface wetting and strong capillary action for completely soldered seams
✔ Standards-tested professional quality – Complies with DIN EN 29454 3.2.2.A (DIN 8511 F-SW 11) especially for demanding roofing and sheet metal work
✔ Economical 1-kg container – Large bottle (1.000 ml), ideal for workshop stock or refilling the job-site soldering station

Maximum pickling power for old zinc & thick oxide layers: FREUND flux for oxidized zinc sheet (1 kg)

The FREUND flux for oxidized zinc sheet (SKU: 66402020) is the specialized problem-solving soldering fluid for sheet metal workers, plumbers, and roofers, for renovation and repair work on zinc components that have already weathered. While conventional fluxes often fail on naturally aged or pre-weathered zinc because of its thick patina, this highly active formula ensures uncompromising chemical pre-cleaning of the joint surfaces.

Based on a concentrated solution of zinc chloride, ammonium chloride and free hydrochloric acid, the soldering fluid removes even stubborn oxide coatings in seconds. It creates the necessary metallic contact, allowing the molten bar solder to flow evenly and penetrate deep into the capillary gaps of the overlap. The generous 1 kg stock bottle provides a perfect supply for the workshop and for filling jobsite kits in portions.

Thoughtful features for the demands of sheet metal work

• Extra-strong activation: Specially formulated for used, weathered titanium zinc, fine zinc and galvanized sheets.
• No bonding defects: Prevents cold solder joints and solder beading on heavily patinated surfaces.
• Tested specification: Manufactured according to DIN EN 29454 3.2.2.A (DIN 8511 F-SW 11) to meet the highest professional standards.
• Safe to use: Easy to dose perfectly with acid-resistant brushes from the LÖTMAX set or jobsite bottles.

Technical details at a glance

• Product name: Flux for oxidized zinc sheet metal
• Manufacturer / Brand: FREUND (soldering fluid "ZD-Spezial")
• Item number (SKU): 66402020
• Category: Sheet metal soldering supplies / Specialty flux
• Contents / Weight: 1.0 kg net contents
• Standard: DIN EN 29454 3.2.2.A (DIN 8511 F-SW 11)
• Composition: Aqueous solution with zinc chloride, hydrochloric acid and ammonium chloride
• Suitable materials: Heavily oxidized / used titanium zinc, galvanized steel sheet, fine zinc
• Soldering method: Soft soldering in roofing and plumbing

Matching Accessories & Add-ons

• FREUND LÖTMAX soldering kit: SKU: 03310000 (The stable 3-in-1 soldering station)
• Sal ammoniac block: For cleaning and tinning the copper tip
• Acid- and heat-resistant soldering fluid brush: For even flux application
• Soldering Rod: For durable soft-solder joints on gutters and sheet metal
• MASC Work Shears 10-inch (MAS10): For precise cutting of film and fleece

Why the highly active FREUND flux 66402020 belongs in your workshop

The key advantage lies in its reliability for repairs and older buildings. Where ordinary soldering fluids fail, this formulation quickly breaks through the dense oxide layer and enables strong, completely watertight solder joints without time-consuming mechanical sanding.

Master even the most difficult zinc repairs. Order the FREUND Flux for Oxidized Zinc Sheet (1 kg) now from the Roofer's Shop at your roofing specialist Roofify!