What flux should I use when replacing PCB components?

CircuitWorks® flux pens are available with a variety of fluxes to fit your specific shop requirements, including: no-clean, high temperature no-clean for lead-free soldering, rosin, and water soluble. Flux pens are an excellent way to dispense flux for benchtop soldering. You just hold the pen vertically and briefly depress the tip to start the liquid flow. This will saturate the tip of the pen with flux. Draw flux on the area to be soldered. Gently press the tip again when more flux is needed to keep the tip damp with flux.