Solder paste for all-tin soft soldering

Emil Otto is aiming at joining steel, stainless steel, brass and copper objects below 450°C with three tin-based soft-soldering pastes.

“The soldering and tinning pastes do not require zinc chloride, are therefore not subject to hazard labelling and can be used for soft soldering and tinning,” according to the company. “Zinnin Green pastes are used in the metalworking industry as well as in electronics production and are also suitable for tinning printed circuit boards

Zinnin Green I is an all-tin paste
Zinnin Green II is SAC305, the Sn96.5 Ag3.0 Cu0.5 paste
Zinnin Green III is a Sn97 Cu3 alloy

“Due to the excellent activity of the contained flux, Zinnin Green III spreads well on the surfaces of the workpieces and penetrates perfectly into soldering gaps,” said company head of marketing Markus Gessner. “If flux residues are formed after the soldering process, they can be removed with deionized water.”

Stirring is required before use, and a colour indicator has been built into the pastes, turning from green in the un-stirred state to metallic silver-grey when stirred sufficiently (see photo).

“This [stirring] is absolutely essential to return the paste to a usable state,” added Gessner. “Stirring can be done with a stainless steel or wooden spatula.”

It is then brushed on before heating.

Zinnin Green web pages: …I (all Sn) …II (SAC305) …III (SnCu)