How to choose a compatible flux to the insides of the solder wire?

[Alexandre Mello]

Hello.

I want to try a new lead-free solder wire, the Stannol KS115 (PN 574101). I contacted their customer service asking for the right flux to use with it, but the fluxes they recommended to me are sold only in 2.5L bottles and this is way too much for my usage. Then comes the question on how to choose a compatible flux to the insides of the solder wire?

The description of the solder is:

"The 574101 is a Solder Wire contains a rosin-free, halide activated synthetic resin. STANNOL KS-Series electronic solder wires have been designed for special requirements of lead-free soldering. They meet all demands of industrial manufacturing as well as for rework and repair. Flux is an excellent combination of high activity at thermal stress with amber bright and electrically safe residues. The flux formulations KS115 are classified to DIN EN 29454-1 Type 1.2.2.B. Due to their high activity (1.0 and 1.5%), the fluxes are classified as REM1 to DIN EN 61190. STANNOL solder wires KS115 is designed for use with robotic and manual soldering for electric and electronic devices. Flux residues may remain uncleaned. This must be examined in individual cases, where environmental stress is applied to the circuit."

The TDS for the fluxes they recommended to me are attached.

Anyone has a tip or a suggestion?

Thanks

[Niklas]

The X32 flux seems to be a safer choice as it is from the same group as the flux in the solder wire. Both are resin type fluxes (RE), moderately activated (M) and the difference is in the halide content (0 or 1).   

[Alexandre Mello]

Hi Niklas.

I’m not in doubt between these two fluxes. Their minimum quantity is way too much for me. I’m trying to figure out what other high quantity flux of another brand can be compatible with this solder I want to try. I just put these two here to help with information that can lead to the right choice, as they were recommended to me by the manufacturer as compatible ones.