DCC Concepts Sapphire No-Clean flux is an ideal companion that will make it possible for you to make perfect joints easily every time in electronics, soldering wires to track, working on or re-working brass, whitemetal or nickel silver kits. In fact anywhere that later clean might be difficult to do! The ONLY time you may want to clean this flux off post-soldering is if you wish to paint the area you have soldered, in that case, a simple wipe over with cloth or cotton bud dipped in Isopropyl alcohol or even methylated spirits is all that is needed