Edsyn fluxi flux in 30ml bottles edsyn fl112 edsyn fluxi fl 112 is a high quality flux for all types of soldering but is particularly suited to use with smd components the flux can be applied selectively and precisely on the points to be soldered using the brush in the lid of the bottle use of the flexible brush helps to prevent damage to sensitive components and parts laboratory tests have confirmed that in general and with careful dosing corrosive residues do not remain on the circuit