840 Solder Flux for Clean Metals


Use When Soldering Clean or New Copper, Zinc and Stainless Steel

The warehouse that stocks our AMG, Freund, Rau, Erdi, Express and Perkeo products will be closed from December 15th 2021 to January 3rd 2022 for the holidays. All orders placed for these products during this time period will begin shipping on January 4th, 2022.



Express Gel Solder Fluxes are designed for soldering copper, zinc and stainless steel metal roofing, wall panels and any project using these metals. This gel flux is perfect for soldering new copper and zinc metal roofing, wall panels and gutters, as well as anything else that needs soldering.

  • 840 Flux (Red Cap) is for use on new, clean metals. 320ml (10.8oz) bottle

Need to solder old, oxidized metals? Use the Express 845 Flux (Black Cap).

This product cannot be shipped by air, so please do not select Next Day Air, 2-Day Air or 3-Day Select.

Hawaii, Puerto Rico and other overseas Customers: UPS & FedEX will not ship this product to Hawaii, Puerto Rico or other overseas destinations with solder flux. 



Express manufactures heavy duty welding tools for sheet metal roofing, plumbing and tradesmen in the metal industry. High quality soldering irons and accessories.

Additional information

Weight 24 oz
Dimensions 5 × 5 × 4 in

Soldering Tool


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