• Cleaning of flux residues

  • Special applications

  • Selective soldering

  • Cable assembling/Wire soldering

  • Manual assembling

  • Wave soldering: foam fluxing

  • Wave soldering: spray fluxing
Water- and alcohol-based flux
Flux for cable assembling
Cleaning agents
Otto's Original - Quality products since 1901

Alcohol-based flux


No clean, alcohol-based flux, synthetic resin, di-carboxylic
acids, halogen-free (WEEE/RoHS conformant)
Type // REL0 acc. ISO 9454 // DIN EN 61 190-1-1


Standard packaging units liter_20 20 L

Appearance:colorless to light yellow, clear
Solids content:2.5 wt%
Density 20 °C:0.794 (+/- 0.003) g/cm³
Acid number:21 - 25 mg KOH/g
Activators/resin:synthetic resin with di-carboxylic acids
Solvents:short-chain alcohols
Flash point:12 °C
Durability:12 months

S-250/FR is universally suitable for wave soldering. It features special additives to ensure a stable, fine-pored foam head. It is used successfully for a wide range of systems and wave types in both leaded and lead-free processes. Its high temperature stability and very good activity over a wide temperature range ensures a wide process window with best soldering results. The surfaces are very clean after soldering, the SIR is above the standards.

S-250/FR is suitable for foam fluxing and not recommended for selective and manual soldering (see also product matrix).

Practice has shown, that in most cases no washing is needed for PCBs properly soldered with S-250/FR. The IC test with needle adapters is generally not affected.

Application (recommended): Wave soldering (foam and spray fluxing)

Customer added value:

  • Very good soldering properties (capillarity, wetting)
  • Broad process window (very high thermal stability, good activity over a long interval)
  • Very good residue behaviour (very clean, high SIR)

product overview

Questions about our products?
We will advise you by phone 06123 / 7046-0.